For our office Christmas tree this year we decided to do something a bit different and build our own. We also needed a new centrepiece for our London reception area after the Leadership Bridge moved to our new Birmingham offices. The design team behind that earlier project was reconvened to tackle this new challenge and once again RCD took responsibility for the geometric design.
We decided to take the opportunity to combine two of our favourite structural forms; tensegrity and hyperboloids.
Tensegrity structures were so-named by Buckminster Fuller as a portmanteau of ‘tension’ and ‘integrity’. While most structures support themselves through continuous solid elements (such as walls or columns) that carry compressive loads directly into the ground, in a tensegrity structure the compression elements are instead separated from one another and held in place by tension members (such as ropes, cables or chains). They are fascinating structures because their behaviour is so counter-intuitive – the solid parts seem to float in mid-air and look as though they should simply drop to the ground. Individually, they would – it is the overall arrangement and precise balancing of tension and compression that provides stability. They are therefore notoriously difficult to design and construct, so it is fortunate that we enjoy a challenge.
Hyperboloid geometries (not to be confused with Hyperbolic Paraboloids) are a special kind of double-ruled surface formed between two circles. They possess interesting structural properties and have been notably used in architecture by Vladimir Shukhov and Antoni Gaudi, among others. It is also possible to use them as the basis for a stable tensegrity module, which is what we did here. (For more information about them, including how to generate them for yourself in Grasshopper, see this recording of my lecture on the topic at Imperial.)
Each module is actually formed of two hyperboloids – the compression elements lie on one surface and the tension elements on another. It is the difference between these two surfaces that give the structure its stiffness and prevent it from collapsing.
The overall tree consists of a stack of five of these modules with differing dimensions. The bottom of each module hangs from the top of the one below with an overlap to give the classical Christmas tree ‘zig-zag’ profile. A third hyperboloid surface formed of tension elements connects the top of each module to the top of the one above – this provides lateral stiffness to the structure and prevents the modules from being displaced.
The individual modules
The geometry was parametrically defined in Grasshopper. We used Kangaroo 2 for some early stage stability checks and to test out different ideas, but then moved onto using a custom-written dynamic relaxation module built on our own Salamander 3 tool, as Kangaroo does not use physically accurate properties in its simulation. For final checks, the model was exported to Oasys GSA (again via Salamander). This was all complemented by some modelling of the old-fashioned kind in order to demonstrate the concept.
No Christmas tree would be complete without lights; ours came in the form of an illuminated base kindly custom-designed for us and provided by Clearvision Lighting.
As a final touch, every tree also needs a star on top. Our star, however, isn’t technically on top of our tree – instead the criss-crossing pattern of elements itself forms a star-like pattern in plan which is then projected onto the ceiling above the tree. The tree is its own star.
In this tutorial, I will provide a very simple demonstration of the use of Grasshopper, a visual scripting environment embedded into the 3D modelling package Rhinoceros and a very useful computational design tool. This example is intended to give a brief overview of how the software works to people with no prior exposure to it and explain the core theoretical principles. Some basic prior knowledge of Rhino itself is assumed, however (i.e. you need to at least be familiar with the general interface – this video will cover most of what you need).
The example should take under 30 minutes to run through but will teach you everything you need to know in order to start using the software by yourself. Each step is accompanied by an animation showing exactly what you need to do.
We’re focusing on Grasshopper in this case, but most of the concepts shown here are also transferable to other similar node-based visual programming environments (for example, Dynamo).
Grasshopper is a free plugin for Rhino and can be obtained from its official website: www.grasshopper3d.com. In Rhino 6+, Grasshopper will be incorporated into the main Rhino install and will no longer need to be downloaded separately. Rhino itself can be downloaded here and will run as a free evaluation version for a full 90 days.
In this example, we will create a very straightforward parametric definition which will draw a line between two points. These two points will be our inputs; create these in Rhino by using the ‘Point’ command twice.
Once Grasshopper is installed, you can run it from inside Rhino by typing the command ‘Grasshopper’ at the command prompt.
Grasshopper’s subwindow will appear, and should look something like this:
The title bar. This shows the name of the currently opened file (if any). It can also be double-clicked to collapse Grasshopper to just this title bar – useful if you are working on a single screen and want to get Grasshopper out of the way quickly.
The menu bar. We’ll talk more about this in a minute…
The component library. This is categorised into several different tabs for different kinds of functionality. (You probably won’t have as many as are shown in the images – many of these are optional plugins.)
The component library is further sub-categorised into different groups. You can click on the title bar at the bottom of each group to expand it and see all of the components in that group with their names.
The canvas toolbar. Contains several quick-tools to save the file, scribble on the canvas and change the way that things are being displayed.
The main canvas. This is where the magic happens.
The recent files grid. You probably won’t see this if it is your first time opening Grasshopper as you won’t have any recent files! This will disappear as soon as you start adding things to the canvas.
The status bar – occasionally displays useful information.
Let’s go back to the menu bar to make a couple of important points:
Grasshopper files can be opened, saved, etc. via the File menu. Grasshopper definitions are saved separately from Rhino files, so make sure you save both if you don’t want to lose any data!
In the ‘View’ menu you can turn on an ‘Obscure Components’ option which will show more components in the library ribbon than you get by default. This option is presumably there to stop people getting scared by lots of component icons when they start out, but also makes it harder to find things.
In the display menu, turn on ‘Draw Icons’. This changes the way components are displayed on the canvas. This is a matter of personal taste and some people prefer the default (which just shows text), but these people are wrong.
You should also make sure ‘Draw Fancy Wires’ option is on (which it should be by default). This is not even a matter of personal taste; having this turned on will make certain definitions much, much easier to understand.
3. Grasshopper Basics
3.1 Adding Components
Now onto the creation of our actual definition.
The first step is to get the points we created in Rhino and put them into Grasshopper in a form that we can use. To do this we’ll need a couple of Point Parameter Components which you can find on the ‘Params’ tab in the ‘Geometry’ group on the component library ribbon. Left click on the icon and then left click again somewhere on the canvas to create one of those components.
This is one way of adding components to the definition. The other way is to search for them by name. To do this, double-click somewhere on the canvas (not on a component). In the text box that appears, type in ‘Point’. It will then show a range of suggestions – click on the component just called ‘Point’.
3.2 Referencing Rhino Geometry
These components are intended to store point data, but at the moment no data has been assigned to them. This is why they are showing up in orange – this indicates a warning, typically that the component does not have all of the inputs it needs to do whatever it is meant to be doing.
We’ll need to set up these components to refer to the two points we created earlier in Rhino. Right-click on the first component to bring up its context menu. Select the option ‘Set one Point’ and then in Rhino pick the first point.
This will assign the point to the parameter and the component should turn grey to indicate that everything is working as planned.
Repeat this for the second component and the second point.
You may notice that little red ‘x’s have appeared over the points in Rhino – these indicate that the geometry is also present in the Grasshopper model. If you left-click on one of the Grasshopper components it will become selected and will turn green. The ‘x’ in Rhino related to that component should also turn green. You can use this to remind yourself which Grasshopper component refers to which bit of Rhino geometry.
3.3 Creating Data Flows
Now that we have our input points in Grasshopper we can generate the line between them. Navigate to the ‘Primitive’ group on the ‘Curve’ tab and find the component called ‘Line’. Left click on the icon and left click again on the canvas to create a Line component.
This component has a few more features than the Point parameter components. Whereas the Point components simply store a bit of data, this Line component represents a process which will consume input data and generate an output from it. The process inputs are shown on the left hand side of the component (called ‘A’ and ‘B’) and the outputs are shown on the right hand side (called ‘L’). Hover your mouse over these letters and you should see tooltips that provide more information about them.
A and B are the start and end points of the line, respectively. We can populate these inputs using the data stored in our Point parameter components. To do this, hover your mouse over the small nodule on the right hand side of one of the point components. You should see a small arrow icon below your cursor. Click and hold the left mouse button and drag the mouse away to see a snaking arrow follow your mouse. Move your mouse over the first input of the line component and release.
This will create a connection between the output of the Point parameter component and the input of the Line component.
Repeat this for the second point and you should see the Line component turn grey and a red line appear between the two points in Rhino.
Congratulations! You now know how to use Grasshopper!
Grasshopper allows you to describe parametric models by essentially drawing a flow diagram of the process you want to follow to create that model. If you can diagram a process, you can use Grasshopper.
All components essentially work the same way; inputs on the left and outputs on the right. Click and drag to create connections between inputs and outputs and choose the way that data will flow between different operations. Simple!
So far we’ve just used this to draw a line, which isn’t enormously useful – we could have done the same thing in Rhino just by using the ‘Line’ command. But the power of Grasshopper comes from the fact that several different processes can be daisy-chained together, with the output of one operation feeding the input of another.
To demonstrate this, we’ll take the curve output from the Line component and we’ll create a tubular surface around it using the ‘Pipe’ component from under ‘Surface’/’Freeform’. Drop one of these onto the canvas and connect the ‘L’ output from the Line component to it’s ‘C’ input.
The ‘C’ input is the centreline curve around which the pipe surface will be created. You should be able to see this surface in the Rhino view. Click and drag one of the two initial points to move it and you should see the pipe geometry automatically update.
This is the power of Grasshopper. Changing an input (in this case a point) will prompt an update of any geometry which is linked to it. The process you have set out will be run again automatically and the model regenerated, without you having to go through all the pain of manually remodelling everything.
Complex chains of hundreds of different operations can be built up and whole buildings can be defined and controlled by just a few simple inputs, with changes automatically propagating throughout the model.
3.4 Number Sliders
The Pipe component is already working even though we haven’t put anything into the ‘R’ and ‘E’ inputs. This is because these inputs have default values – hover your mouse over these letters to see what those default values are. ‘R’ is the radius of the pipe, which we might want to be able to adjust. (We won’t bother looking at ‘E’ in any detail, but this can be used to control what the ends of the pipe look like).
We’ll control the radius with a Number Slider component from ‘Params’/’Input’. Drop one onto the canvas and connect the output to ‘R’ to override the default value.
This is a little input widget that we can use to control a numeric input just by dragging the slider left and right. If you want to change the maximum and minimum values right click on the slider and click on ‘Edit’ to access a form which will let you set up the properties of the slider, including the numeric domain it covers.
Grasshopper features many different input widgets that allow you to enter and modify different types of data easily.
We’ve now finished creating our definition for this example, but we will use the model that we’ve made to explore a few other aspects of the program.
4. Geometry Preview
You may already have noticed that the red transparent geometry that you can see in Rhino has some peculiar properties – you can’t select it, it won’t be saved in the Rhino file if you try to save it, if you hit the render button then it won’t show up, etc. This is because none of this geometry actually exists in Rhino yet – it is merely a ‘preview’ that Grasshopper is drawing in the Rhino viewport to show you what is going on.
If you want to turn this preview off – now that we have our pipe you might no longer care about seeing the centreline geometry, for example – you can turn it off by right-clicking on the middle part of the relevant component (not over one of the inputs or outputs) and toggling on or off the ‘Preview’ option.
The preview geometry associated with that component should disappear and the component should turn a darker shade of grey to indicate that its preview is turned off.
You can also change how everything is displayed using the first three buttons on the right-hand side of the toolbar just above the canvas, to ‘off’, ‘wireframe’ and ‘shaded’ modes respectively.
To add this previewed geometry to Rhino, so that we can manually modify it, export it, render it, etc. we need to ‘bake’ it. This will add a copy of that geometry into the current Rhino document.
To bake some Grasshopper geometry, right-click on the component whose geometry you wish to add to Rhino (again, this needs to be on the centre part of the component, not over any of the input or output components) and click on the ‘Bake’ option. This will throw up a small form which allows you to select certain properties of the new object in Rhino (for example, the layer it will be placed on). Click ‘OK’ to bake the geometry.
You can now modify, delete, move, export etc. this geometry the same way you would any other Rhino object. Note that there is no link between this baked object and the Grasshopper definition that created it – if you change the model in Grasshopper these changes will not be reflected in the Rhino model and likewise changes made to the geometry in Rhino will not matter a jot to Grasshopper. If you wish to later update the Rhino geometry from the Grasshopper model you will need to delete it and re-bake; for this reason it is a very good idea to keep baked geometry on its own set of layers in Rhino so that it can be easily selected and deleted in one go.
6. Data Matching
One advantage of Grasshopper is that, as we have already seen, (non-baked) geometry can be parametrically linked and automatically updated. Another advantage is that once we have a process defined, we can apply that process over and over and over again on multiple inputs, which is what we will do now. We do not have to modify our actual model definition at all for this; we simply need to change the inputs.
Rather than creating a single pipe between two points, we will now use our definition to create multiple pipes between multiple pairs of points. Add four more point objects to your Rhino model (using the ‘Point’ or ‘Points’ command) for a total of six.
Right-click on the first Point parameter component. Just below the option to ‘Set one Point’ is another which allows you to ‘Set multiple Points’. Click on this option and select in Rhino the three points you want to use as pipe start points. Press return or right-click once you have finished.
Note that this will override the data previously stored in this component, so you’ll need to include the original start point in this selection if you want to include it.
This component now contains multiple bits of data. Those multiple points are being passed along to the Line component and it is now generating three different lines from each of those three points to the single end point we currently have selected. Those three lines are being passed in turn to the Pipe component to create three different pipes. You can tell at a glance that multiple pieces of data are being passed between components by looking at the wires between them – provided you have the ‘Draw Fancy Wires’ option turned on these should now appear as double-lines rather than one. This indicates that a list of data is being passed along that connection instead of just one individual piece of data (which will be a single line).
Repeat this operation to set the three end points.
We now have three start points and three end points going into our Line component, and as an output we are getting three lines (and consequently, pipes). You might have expected that we would get nine lines connecting every start point to every end point, but instead Grasshopper is ‘pairing up’ start and end points and just creating one line for each pair – this behaviour is known as ‘Data Matching’ and it is a very important concept to understand when using Grasshopper.
Whenever a component has multiple pieces of input data plugged in Grasshopper will first determine which sets of inputs to use together and then will run the process once for each set. To figure out which inputs belong together, Grasshopper follows two simple rules:
RULE 1: When matching two or more lists of objects, items at equivalent positions in those lists will be matched together.
So, the first item in the first list will be matched with the first item in the second list, the second item in the first list will be matched to the second item in the second list, third with third, fourth with fourth and so on.
Imagine we have two lists of letters – in the first list we have A, B, C, D and E, while in the second we have F, G, H, I and J. Data matching these two lists together would give us the pairings A-F, B-G, C-H, D-I and E-J.
So, the order that things are stored in is important – in this case the order that the points were selected will be the order that they are matched up in.
This all works great when we have lists which are all the same length, but what if one is shorter than the others? This is where the second rule comes in.
RULE 2: When one list is shorter than the others, the last item in the list will be matched with subsequent items in the others.
Grasshopper will ‘re-use’ the last item in a list when there aren’t any further pieces of data to match up. If we dispose of the last two letters in our second list (so list 2 is now just F, G and H) the resultant pairings will be A-F, B-G, C-H, D-H, E-H. H will be used in three different pairings!
We can see this effect in action by setting our ‘end points’ input to only contain two points (or just one, as we originally had it) while the start points have three:
Now, the last end point will be connected to the last two start points.
This behaviour applies to any component and any type of data, not just lines and points. This means that we can take advantage of this to give us individual control over the diameter of each of the pipes we are creating.
Create a second Number Slider (you can press Ctrl-C, Ctrl-V to copy and paste the one we already made) and connect it to the Pipe component ‘R’ input. If you try and do this normally it will automatically replace the connection to our original slider, but if we hold down the shift key as we’re making the connection we can connect multiple outputs to one input.
Our ‘R’ input will now be a list of numbers comprising the values of the sliders that we’ve plugged in (in the order that you plugged them in) and these will be data-matched with the list of curves going into ‘C’. As a consequence, the first slider will control the radius of the first pipe and the second will control the radius of the others. If we wanted, we could add more sliders to give us total control over each pipe.
You now know everything you need to get started using Grasshopper. There is certainly a lot more to learn – there are thousands of different components available and as well as flat lists data can also be passed around in the form of multidimensional ‘Data Trees’ (essentially, lists of lists), which can make data matching a lot more confusing, but these all follow the basic principles we have covered here.
Becoming more proficient is largely just a matter of learning what tools are available to you and of getting used to manipulating the data flows between components to achieve the effect that you want. The best way to start is simply to choose something that you want to model, think about the basic geometric steps you would take to create it manually and then try to express that process in Grasshopper.
The official Grasshopper forums feature a very active and helpful community and are a useful resource to get help. For a little more structured learning, the ‘Parametric Engineering’ course that I co-teach at Imperial College London is available to view on YouTube. You can also discover how to use Grasshopper to create parametric structural analysis models via RCD’s Salamander plugin in the video below:
RCD’s Footbridge Layout Early Assessment (FLEA) tool is an interactive client-focussed App which was developed rapidly in the space of just two weeks in order to address a specific project’s needs.
The context of the project was a busy public road and complex junction separating one of our client’s buildings from the rest of their campus. The need had been identified for a footbridge to provide a safe and secure route for their staff to move between the two sides, but the precise location and alignment of this new bridge was not yet fixed.
To aid with the decision-making process RCD, in close collaboration with bridge engineers in our London and Southampton offices, developed a small generative App that would allow exploration of the various options. The tool allows the client to simply click and drag to move the bridge ends. The structure between these two points is generated, following various set-out rules coded into the software.
A simple static analysis is performed by the tool itself, which allows key members to be automatically sized. Complementing this was a series of far more detailed studies done by our bridge engineers on a range of geometries within the continuum of possible options. By using these data points as a guide, we were able to have the tool calculate and display in real-time an estimation of the overall structural tonnage for any arrangement the client cared to investigate, which we could be confident would be accurate.
Typically, a structural engineer might investigate only two or three different options in such a study. By instead developing a bespoke tool that could interactively analyse any potential arrangement we were able to be far more analogue and put the client firmly back in the driving seat.
A Load Take-Down is a procedure frequently performed by structural engineers to assess the amount of loading carried by the columns of a building into its foundations. It is an important early-stage analysis necessary to inform the choice of column layout and foundation system, but it is also a notoriously tedious and time-consuming process that is regarded as something of a ‘rite of passage’ for young engineers to endure.
Typically, the take-down is performed in one of two ways. Either the tributary areas (the region of loading that each column nominally supports) must be calculated manually for each column on each floor and then tallied up (commonly via a spreadsheet), or a full 3D finite element model of the entire building must be constructed and the forces extracted. The latter requires resolution of a level of detail which is often inappropriate during the early phases of a project and the former is both slow and prone to errors. Most importantly, both methods can require significant re-work in order to adapt the analysis to modifications of the geometry and this limits our ability to experiment and respond to design changes.
RCD’s TADPOLE (TAke-Down Process On Loaded Elements) is an in-house software project that provides a new alternative method that automates and greatly speeds up the analysis. The standalone tool can read in 2D floor plan drawings and assemble them, level by level, into a complete representation of the building. Loading areas and column positions can be automatically interpreted by the tool if present, otherwise the software contains a full suite of drawing tools to allow the engineer to sketch out loads, columns, walls etc. Once this data has been input the software automatically determines tributary areas and performs the take-down. Changes to the input data can be made easily and the impacts assessed instantly.
This eliminates the need for tedious manual calculation and, because the application is designed and streamlined for this specific purpose, there is no need for any extraneous data to be input. Because the tool is graphical, odd results and input errors can be spotted and traced far more easily than in a spreadsheet.
To help further manage the data the results of the analysis can be output to an interactive online dashboard via Power BI, making it easy for the lead engineer and client to interrogate. A full report can also be generated to document the process, results and assumptions. To eliminate re-work, the tool can also assemble the input plans into a full 3D building model that can be exported to Autodesk Robot to form the basis of a more detailed analysis.
This has allowed us to do in hours what would previously have taken days, and in a way that would not have been possible without building the tool ourselves. Commercial software is typically made to be as broad as possible in order to capture a wide user base. This means that it is often poorly optimised for certain tasks. By developing our own tools designed to meet our exact requirements and workflow we can plug these gaps and work more efficiently, enabling us to beat time pressures by responding faster, iterating more often and, ultimately, to produce better, more rigorously-checked designs.
Salamander 3, a new structural modelling and interoperability tool developed by RCD lead Paul Jeffries, is now in open beta and available to download from Food4Rhino. The tool adds the ability to model structural elements such as beams, slabs, nodes etc. inside Rhino and for this data to be exchanged with analysis packages (at present, Autodesk Robot and Oasys GSA).
The tutorial videos below demonstrate how to install the Rhino plugin and utilise some of the basic modelling commands in the tool to develop a simple structure.
A recording of the talk I recently gave as part of the ‘Design Discourse’ series at Imperial is now available on YouTube, here:
Unfortunately many of the animated embedded .gifs in the presentation did not display properly on Imperial’s hardware (computers, eh?), so they have been included below instead – click on each one to view the animation:
SketchPad – the first graphical CAD tool – in operation.
On Tuesday 16th May Paul Jeffries will be delivering a public lecture at Imperial College London entitled ‘Emergence: The development and future of computational design’. The talk will be held in Room 201 of the Skempton Building and begins at 18:30. All are welcome to attend.
For the 2017 Ramboll Leadership Conference in Copenhagen, which took place on the 22nd and 23rd of January, RCD was involved in a collaboration between the Transport and Buildings departments to design and construct a ‘bridge’ installation between their respective stands. We had a little over a month to develop and manufacture the design so timescales were tight and we had several key criteria to consider – the bridge was to support a model train running between the two stands (in reference to the Holmestrand Mountain Station project), it needed to be light and easily demountable enough for us to carry from London to Copenhagen, build in an afternoon, break down in an hour and then return back to London (for later re-assembly in our home office). We also wanted it to form an interactive part of the conference rather than merely being a static display piece.
We approached the project the same way we would any other – pulling together a team with relevant expertise, brainstorming ideas, analysing and developing them. For the interactive element, we realised that business cards made an ideal impromptu craft material and were one of the few things we could rely on most of the attendees to be bringing with them. The decision was thus made to allow people at the conference to leave their business card, folded into a specific 3D form, as part of the bridge’s cladding.
Design of the overall structure progressed rapidly through several meetings, based around a flexible parametric Grasshopper model developed by RCD that allowed for collaboration around real-time adjustments to the geometry. After the examination of several options we settled on a timber shell/arch structure as an aesthetically pleasing, lightweight, robust solution that would reference both Ramboll UK’s expertise in timber structures and previous RCD project the TRADA pavillion and which could be rapidly manufactured and assembled.
Throughout the development of the bridge the geometry was exported to and analysed in MIDAS by the London Bridges team in order to make sure the design was structurally feasible and to guide further refinement of the form and material thicknesses. Additionally preliminary samples of sections of the bridge were laser cut to allow us to physically examine and test the manufacturing process and connection detail design.
In order to enable the bridge to be rapidly assembled and disassembled we wanted to avoid the use of adhesives or mechanical fixings. The connections were therefore designed as simple slotted plates, held in place laterally by a matching slot in one of the plates they joined and restrained laterally by small standard ‘U’-shaped clips, all cut from the same 6mm plywood as the rest of the structure. The nature of the shell form meant that the angle between each panel (per quarter of the structure) was different. Generation of these connector pieces was thus integrated into the Grasshopper model in order to determine cutting patterns for each connector and panel, each of which was also automatically labelled with a number to be engraved onto the inner side of each piece to allow easy identification of which pieces connected together during construction. Each connector also incorporated a small hole through which the line which would support the bridge deck could be passed.
The slots into which business cards could be placed were likewise incorporated into the Grasshopper model, arranged so as to fit in the maximum amount of business cards without compromising the structural integrity of the panels. Due to the variety of panel shapes and sizes no one placement algorithm was found to give consistently good results, consequently two separate arrangement algorithms were utilised to determine slot placement and the best of the two automatically selected for each panel to give the final arrangement.
Foundation design is a key component of any project and this one was no different. Two pedestals were designed to support the feet of the bridge. As an arch, the natural reaction of the structure under load was to try and push outwards. To resist these thrusts without having to tie the base of the arch together or carry over heavy weights in our luggage, these pedestals contained hidden compartments to conceal bottles of water which were procured on-site and provided the necessary ballast.
This being a conference for engineers in Denmark, it was a foregone conclusion that the train the bridge would carry should be made out of LEGO. The train in question came with a seven-speed remote control, however to avoid having to manually drive the train for two days straight it also fell to RCD to automate this by hacking the controller. The rotary dial which controlled the train’s speed produced different signals when turned clockwise or anticlockwise – instructing the train to accelerate and decelerate. By hooking up these contacts to an Arduino Uno board programmed to mimic these impulse patterns it was possible to control the train’s movements programmatically and have it moving backwards and forwards across the bridge without human intervention. Unfortunately several key wires were damaged in transit, requiring some frantic (but ultimately successful) repair work with a borrowed soldering iron the day before the conference.
Besides that, the bridge made it to Copenhagen without damage and was erected successfully at the conference. It proved very popular with the conference attendees, becoming packed with business cards by the end of the second day and successfully demonstrating the capabilities of computational design and collaboration to the wider business.
“Our team was made up of people with different skills sets and backgrounds, who were unified by a desire to create something unique. The bridge was a success because all team members contributed their technical expertise, yet listened to and challenged each other to continually improve and refine the design.
This project shows that having the right mix of people with a passion for a common goal can generate great design in a short period of time.”– Sarah Ord, Project Manager
“The Transport and Buildings teams collaborated seamlessly, bringing our respective strengths together created a more complete and superior design
“The use of parametric modelling and rapid prototyping and manufacture released the team’s time to concentrate on the creative design of the bridge through swift iterations. Designing and building the bridge in one month would not be possible without this approach”– Ollie Wildman, Director
“I worked on the structural analysis of the bridge ensuring that the design was robust enough to stand and carry the applied loads. It was great to have worked on such an innovative project and of course it could not have been done without this amazing and passionate team. Overall it was a brilliant experience and I am looking forward to work on similar stuff in the future!”– Neophytos Yiannakou, Bridge Engineer
“Parametric modelling has enabled quick optimisation and adjustment of the bridge geometry, making it easier to model and analyse. In a short period of time we were ready to print and test a first prototype, which has been key to meet the project deadline
“It has been a wonderful experience to design and actually build the bridge with such a diverse and motivated team. It is in projects like this where you realise the potential of combining different disciplines.”– Xavier Echegaray Jaile, Bridge Engineer
The complete bridge is now on display in the reception area of Ramboll’s London offices at 240 Blackfriars Road.
From January 2017, Imperial College London will be running an evening course on Parametric Engineering, co-taught by RCD lead Paul Jeffries. The course will cover the application of Rhino and Grasshopper for computational design within an engineering context and is open to anybody in full time education or academic employment. To apply contact Simply Rhino.
If you’ve arrived at this blog, you will probably have had some exposure to the concept of ‘computational design’. You may also have heard some of the related terms that fall under this heading – ‘parametric design’, ‘algorithmic design’, ‘generative design’ and so on. As computational design is still a relatively young and evolving field the meanings of these terms can be a little vague and are used by different practitioners in different ways. This article presents the vision of computational design that we have in Ramboll and the role that we see it having in the future of the industry. This is what *we* mean by computational design.
But, before we can answer the title question we need to first answer another – what is design?
Even within a single discipline, we might divide the process of delivering a project into two – the mental and the physical. In the former category we have the cerebral work that goes into a design – generating ideas, understanding requirements, thinking (and talking) through problems and deciding on the fundamental principles that go into forming ‘the design’. But this cannot stay a purely ephemeral undertaking – we as designers also need to test our ideas and communicate them to our clients and colleagues and for this we must engage in a range of more tangible activities – performing calculations, writing documents, producing drawings and models and so on. These are not merely end-products, however – they are integral to producing a better understanding of the problem we are trying to solve and the implications of our assumptions in solving it. There is thus an interplay between the mental and physical sides of design. The process as a whole is highly iterative, with many embryonic design options dreamt up, examined and refined or discarded on the way to the ultimate solution.
Recently, computers have been increasingly used as a method of production, to the extent that the second half of the above equation might often be termed ‘virtual’ rather than ‘physical’. Whereas previously we would have produced drawings by hand, we now more commonly draw on the computer using CAD (Computer-Aided-Design) packages such as AutoCAD and Rhino. Whereas in the past we would have had to physically construct an architectural model to see what a project looked like in 3D, we can now build and view a virtual 3D model, perhaps with additional detailed information embedded into it. Whereas we would have had to perform engineering calculations by hand we now have a plethora of software packages available to perform analysis and run through standard calculations on our behalf.
These are some of the ways in which computers are now used in design, but is this what we mean by computational design?
These technologies augment the process of design to make it more efficient, but they do not represent any fundamental change to the process itself. The first generation of CAD software set out to replicate as closely as possible the previously existing paradigms – they swapped out the mechanical pencil for the mouse and the eraser for the delete key but otherwise the experience was maintained. To draw a line, you press down and move your hand from start to end. This was deliberate and, to an extent, necessary during the first transition into the virtual world, but in treating a computer as merely a replacement for a sheet of paper the true power of computation was overlooked.
Computers are not inanimate objects. They are machines of logic and process. They can think; not quite in the same way we do but in a way which is certainly compatible. That means that they can be integrated not only with the physical aspects of the design process but with the mental ones as well.
A (good) design is a fundamentally logical construct. Every aspect will have some reason to be the way it is, whether that is structural, functional, aesthetic or some combination of the above. Walk into the office tower of your choice, for example, and you are likely to find that the columns which support the building are not arranged randomly – they will be evenly-spaced and follow a regular grid. This is done to make the structure more efficient, easier to build and to allow for standardisation of components. Where columns deviate from this grid there will likewise be good reasons for that to be the case – perhaps to keep an auditorium space column-free, perhaps to allow enough clear space for access to be provided for large vehicles, perhaps to better support large loads from above. Each column will have an underlying logical process determining its placement.
Traditionally, it would be for humans to both decide upon this logic and then work through it to determine the arrangement it suggested, drawing or modelling the result. But this second stage is well within the capabilities of the computer, which is after all nothing more or less than a machine for the evaluation of logical processes. If the human can describe the principles driving the design in a form that the computer can understand – i.e. as an algorithm – then the computer can begin to take on a much larger role in the design process, becoming not just a recipient of data but also a generator of it, creating the design representation from the rules the designer has set. This shift is what demarks Computational Design as distinct from simply using computers in a more traditional design exercise.
In brief; Computational Design is a change in the medium of design expression from geometry to logic.
There are a number of advantages to this approach; firstly being that the geometry of the design tends to be changed far more often than the logic. As a structural engineer, I may want to try out several different arrangements of the column grid in order to find the frame that best fits the geometry and construction type of the project. I am unlikely, however, to discard the principle of using a regular grid altogether. If changing the grid means having to redraw every single column position, or perhaps even having to fully recreate from scratch whatever analysis model I am using to make my assessment, that is going to limit the number of options I can feasibly examine (and make me far more likely to stick with whatever I first came up with). If changing that grid merely means adjusting a few input parameters of my generative model and having everything else done for me by the computer then I have far more freedom to explore the design space, find a more optimal arrangement and to adapt to external changes and new information introduced later in the design process. I can, in short, come up with a better design.
Leaving the resolution of the design logic to the computer also removes the restriction that said logic must be resolvable by humans. When rules begin to combine with one another their effects can sometimes be hard for the human brain to visualise. A fractal image, for example, is typically generated by very simple operations repeated over and over and over again, but while the rules may be easy to understand it can be very difficult to anticipate the geometric result without prior experience. So too with buildings, the many competing design drivers of which are often dealt with through simplification and convention far more than they are by optimisation. Computational design allows us to break through these barriers and produce responsive virtual models to do what brainpower alone cannot.
Computational design is an excellent means of dealing with complexity, whether that complexity is caused by the interaction of the factors we have control over or the uncertainty surrounding the factors we don’t. Traditionally this approach has been applied mainly to niche projects whose obvious visual complexity demanded it – buildings with highly sculptural forms, intricate facades and so on that would be next to impossible to design through any other means. However, all projects are complex in their own way, and can benefit from automation to handle that complexity. At Ramboll we recognise this, and so are working to make computational design technology and expertise a more deeply embedded and mainstream part of our design process across all types of project.
Building Structures Director Stephen Melville was recently invited to the Digital Design-themed Henderson Colloquium.
The aim of the annual event is to bring together a select group of industry experts to discuss a subject of topical importance with a view of making recommendations to the engineering and construction industry.
The invitation to attend the roundtable reflects the growing perception of Ramboll as digital design and thought leaders within this cutting-edge field. Other guests in attendance represented firms including Arup, Foster+Partners, Zaha Hadid Architects and Laing O’Rourke.
IABSE has held the two-day colloquium annually since it began in 1975. The event sees a specially invited group of invited guests taking part in a topical discussion of a structural engineering theme, with each participant making a presentation which is designed to stimulate a lively debate.
A summary of discussions and recommendations made for industry will be announced at the IABSE conference in Madrid this September. Whilst the recommendations are confidential until then, Ramboll’s involvement in the event (including a presentation on ‘Meta Parametric modelling’) and debates demonstrate that our focus on importance of design using digital tools and strong philosophical approach to the subject position us as leaders in the rapidly evolving and specialised discipline.
Kristjan Nielsen of the RCD team has recently returned from Hong Kong, where he helped run the SG2014 workshop cluster entitled: The Bearable Lightness of Being. The goal of the cluster was to design and construct a flexible, light-weight and optimised pavilion, through the use of grasshopper plug-ins Karamba and Octopus.
More information on the cluster can be found here.
The RCD team have recently had a paper accepted at the AAG Conference, held this year in London on 18th-22nd September. The paper describes the work done by RCD during the Ongreening Pavilion project, constructed in March this year. In the paper, the form-finding process of a bending active shell structure is described, as well as documenting how the assembly method was influenced by real-time structural analysis using Karamba (plug-in for Grasshopper).
More information about the conference can be found here.
RCD and Ramboll Italy have assisted in the geometric tiling of the Vanke Pavilion, by Libeskind Studio for Milan Expo 2015. The pavilion’s doubly curved exterior will be clad in bespoke ceramic tiles of identical size and shape. In order to achieve this, we developed an algorithm similar to the Chebyshev Net approach to generate the layout and minimise the amount of special tiles required.
RCD are currently working with KAAN Architecten on PLANTA, a new Art Museum to be situated in Lleida, Spain. The building is a reinforced concrete single storey structure, partially buried underground.
As part of the ongoing design, we produced an optimisation study for the 200x70m concrete waffle roof slab in order to improve its efficiency. A bending stress field informs both the subdivision of an orthogonal waffle layout and the varying of its depth to generate a suitable distribution of structural material.
The Ramboll UK Cambridge office have constructed a small timber shell for the Papworth Trust, a local charity that works with those who have learning disabilities.
RCD assisted by generating the plate shell geometry, using the planar remeshing method previously seen on the TRADA Pavilion. The method allows doubly curved shells to be constructed with planar elements, utilising the 3-plate principle to allow a hinged connection whilst maintaining the rigidity of the shell.
RCD’s work on the intelligent modelling of voids in the stems and canopies of the Oxford Brookes School of Architecture Rain Pavilion has been accepted as a paper to the eCAADe 2014 conference in November. The paper Populating surfaces with holes using particle repulsion based on scalar fields will be presented at the annual gathering at the University of Northumbria and contributes to the overall theme of fusion; data integration at its best.
Details of the conference can be found here
The 2014 EcoBuild exhibition at London’s Excel centre opened this week and an egg-shaped plywood pavilion designed for OnGreening’s stand at the event is showcasing the work of Ramboll Computational Design (RCD).
OnGreening is a new web-based platform devoted to the research and profiling of green building technologies. The organisation required a pavilion and lecture theatre that would make them stand out from the crowd at the world’s largest event for sustainable design at the ExCel centre in London.
The look of the structure is intended to echo Ongreening’s goal of capturing and filtering the world’s knowledge of green data. The pavilion has already attracted a lot of attention.
The pavilion’s egg-like geometry was generated using form-finding techniques pioneered on previous RCD projects. The structure itself is unique in that it uses thin 6.5mm birch plywood timber laths which are bent into shape, creating a so-called ‘bending active’ structure which is incredibly stiff and acts like a monocoque, enabling the shell to carry most of the stresses.
The timber laths are aligned along geodesic lines between pre-seeded generation points set out using a parametric model. The primary geodesic members are restrained by secondary laths of the same narrow and thin profile of plywood with a simple bolted connection. This method allowed the use of straight and short length pieces of timber, making it more practical to purchase and build compared with other similar looking structures.
Further details about OnGreening and their work are available on their website.
Ramboll Computational Design has been appointed to provide structural and in addition to computational design services on a pavilion to be built in Milan for EXPO 2015. We will work with Studio Daniel Libeskind and VANKE, China’s largest residential developer, to design and build their Pavilion.
By using generative modelling and coding techniques, the computational design team (RCD) digitally sliced and analysed the pavilion’s structural design, as well as providing the panelling geometry for the pavilion’s exterior which will be covered in bespoke ceramic tiles. By digitally rationalising the façade surface, the complex pattern has been optimised to enable it to be realised from identically sized tiles.
The corporate pavilion will be three to four storeys tall. Containing a bamboo structure and Chinese artworks, the pavilion will be dismantled and rebuilt in China after the expo, echoing the sustainability theme of the Italian exposition. Construction will start in May this year ahead of the exposition.
RCD have collaborated with the staff and students of the Architecture and Fine Arts departments at Oxford Brookes University on a striking new urban intervention/sculptural pavilion at the entrance of the new Abercrombie building. The structure compromises 20 extremely tall and slender steel ‘trees’ that support a thin folded steel plate ‘leaf’ or canopy. The overall impression is that of a wooded glade where light is filtered through varying diameter circular voids in the canopies and the stems bathing the visitors to the installation in a dappled light. RCD were an integral part of the conceptual design process following the initial student competition.
The extreme slenderness of the stems (only 89mm diameter and 6000mm tall) required extensive input from Ramboll’s fluid dynamics team in Copenhagen and fatigue analysis by our Advanced Engineering team in Southampton to model the complex wind interactions in order to prevent dynamic failure and to keep the structure as slim as possible. The canopies are 2500mm at their widest but only need very thin steel plate (2mm) because of the inherent stiffness provided by folds and creases in the form.
We developed routines to allow the circular voids to intelligently self organize on the surface of the stems and canopies in relation to the level of stress. High stress in a particular area meant that voids were fewer in number. Dampening factors were built into the initial coding to ensure that the overall impression of the holes was a gradual fading rather than unsightly bunching. The work will be extended to include our work on integrating a lightweight finite element solver within the automatic void generation and movement process in order to give more control and instant feedback on structural performance. A technical paper will be presented at a future paper conference.
The TRADA Pavilion project from 2012 used numerical form-finding to derive its shape. By using shape functions to apply a dynamic load at each node, a continuous funicular (compression only) shell was found.
The KREOD Pavilion has won a coveted Structural Award at the prestigious ceremony at The Brewery in London. The awards are held annually by the Institution of Structural Engineers (IStructE) to celebrate excellence in structural engineering both in the UK and internationally. The KREOD Pavilion won the Small Project award.
KREOD Pavilion is a sustainable, portable, demountable and multi-functional indoor or outdoor exhibition space that was launched at Peninsular Square near the O2 and Emirates Airline at North Greenwich in London in 2012. Pavilion Architecture led the project.
KREOD’s organic form is inspired by nature, closely resembling a seed. It sits on castors allowing the structure to be moved and rearranged into different forms. Ramboll’s Computational Design (RCD) team contributed to the conceptual design of the pavilion, helping to translate the concept into a rational and buildable form using high technology and imaginative engineering – a creative design led by constraints on cost and appearance.
The team developed digital design techniques to model and shape the pavilion leading to a more efficient and buildable form. They also made innovative use of a reciprocal jointing system that can be fully dismantled and flat packed. The project saw the first use of Kebony a structural element, which required the Computational Design team to embark on a programme of material testing at Cambridge University.
The judging panel praised the KREOD Pavilion for its pioneering approach to creating a functional and demountable enclosure in a striking yet sustainable way:
“Once in a while developing new techniques and processes, coupled with imaginative and perceptive engineering skills, allow the realisation of a design that previously would not have been feasible or financially viable. Though temporary by nature, the KREOD Pavilion is a seminal structure, demonstrating the possibilities of the exoskeletal approach to permanent habitable buildings of the future”.
As part of the Bartlett School of Architecture Plexus series of lectures John Harding of the Ramboll Computational Design team spoke about structural form-finding at RCD. The talk focussed on how computation can help to bridge the gap between architecture and engineering at the early stages of projects where there is most to be gained.
The Bartlett Plexus series is an initiative to bring together the creative talent of different disciplines to share techniques, solve problems and build networks of collaboration. The events will happen every other month inviting young designers, architects, engineers, programmers, game designers and visual artists.
Ramboll Computational Design (RCD) has been selected to design modular toilet buildings for schools throughout India.
The client is a joint venture between a UK-based investor who specialises in funding female entrepreneurs throughout the developing world and NVH Technology, an award-winning entrepreneurial provider of sanitation services in India.
The client plans to expand their range of commercial products into toilet facilities for schools, and has appointed Ramboll to provide design services. The client approached Ramboll Computational Design after seeing RCD’s presentation on the Trada Pavilion, given at the Ecobuild exhibition in London’s Excel Centre earlier this year.
This is an exciting project for Ramboll as it broadens our product design expertise and capabilities in design for mass manufacture. It also provides an opportunity to create a significant beneficial impact on improved sanitation and achieving universal education through improving the standard of school facilities. The United Nations estimates that up to 2.5 billion people worldwide lack access to basic sanitation and reforming this situation is a United Nation’s Millennium Development Goal.
As a commercial venture, Ramboll have worked with the client to develop a unique fee structure which is partially based on royalties gained through the licensing of Ramboll’s intellectual property. Additionally, a custom scope for product design work was prepared and tailored to the client’s particular brief.
John Harding of the RCD team will be presenting our work on the Trada pavilion at the International Associate for Shell and Spatial Structures symposium in Wroclaw, Poland on the 23rd September 2013. The talk, simply titled The TRADA Pavilion – A Timber Plate Funicular Shell will be given as part of the session dedicated to Structural Morphology – Faceted and origami structures.
The Rambøll Computational Design (RCD) team were invited to help design a number of installations at the world-famous Burning Man Festival in Nevada, USA this year by Westminster University School of Architecture.
Burning Man is an annual event held in the Black Rock Desert in northern Nevada. It takes place annually beginning on the last Monday in August, and ending on the first Monday in September to coincide with the Labor Day national holiday. The event takes its name from the ritual burning of a large wooden effigy on the Saturday evening and is described as an experiment in community, art, radical self-expression and radical self-reliance.
The week-long gathering of counter culture takes place in August, giving the team a very tight programme in which to design three climbable sculptures, two recursive ‘fractal’ forms, and a double curved and cantilevering timber shelter, and then help organise their digital fabrication.
In recognition of RCD’s recent experience of collaborative digital modelling of unusual forms, combined with the hands-on production of the Belvedere festival sculpture in New York and Trada Pavilion in the UK, our team were invited by tutors at the Westminster University School of Architecture to assist the student team that won the international design competition earlier this year.
The KREOD Pavilion has secured a place on the 2013 Structural Awards shortlist. The Structural Awards are held annually by the IStructE to celebrate international excellence in structural engineering. KREOD has been shortlisted for the Small Projects award. The full shortlist can be found on the Structural Awards website.
Ramboll Computational Design have conceived and created a weave shell structure from strips of Perspex to transform the foyer of our London studio. The unique doubly-curved triaxial mesh shell installation explores how engineering, digital fabrication, and imagination can fill the boundaries of the space. It inherits the tradition of innovation and material exploration from our 2011 Foyer 1.0 timber principal curvature shell but extends the automatic form finding and associative modelling in new directions. The form has been generated using our self coded dynamic relaxation techniques and the cutting patterns for the flat perspex elements are automatically generated from the Grasshopper model.
The structure will built by early September in time to feature in the London Design Festival 2013.
Ramboll engineers have conceived the Fitzrovia Chalkboard for the Great Titchfield Street Festival as part of London Festival of Architecture 2013. One of a number of events planned for the month long festival, the inaugural street project will promote positive change in the area, transforming Great Titchfield Street – from Mortimer Street up to Langham and Foley Street – into a pedestrianised haven for the day.
Fitzrovia Chalkboard is a temporary installation that creates a single point of display for collective messages in the local community – a structure that is a massive writing surface for all to contribute. It is inspired by how local, independent businesses rely on the traditional chalkboard as a means to advertise and mark their place on the street, in a time when technology offers many alternatives. Fitzrovia Chalkboard is designed using such recent advances and the public are invited inside the structure to view its innovative construction.
Inspired by Ramboll’s recent Trada Pavillion, the structure comprises of 47 birch plywood panels joined together by steel hinges. It is designed using the Tangent Plane Intersection (TPI) methods developed by Ramboll Computational Design to break down any double curved form into flat planar elements. Exact cutting patterns for digital fabrication are then automatically generated from the TPI mesh. All panels are numbered sequentially and this approach ensures that all panels fit together to create the form in a quick assembly process.
RCD collaborated with Architects and light installation artists Cinemod on the design for the RIBA organised Radio 4 Listening Pod competition, a brief to create a portable and memorable looking recording studio.
Christened the Geode, the pod was inspired by natural mineral formation and by the TPI mesh surface techniques developed by us on the Trada Pavilion. The TPI mesh enabled the structure to be broken down into small, light and easily transportable plywood and acoustic foam components which could then be slotted together on site by hand. Our entry was not shortlisted but did us give a valuable opportunity to develop the planar intersection modelling techniques further, to build on our knowledge of digital fabrication and to explore new ideas with creative partners.
Our KREOD proejct has been shortlisted for the BCI (British Construction Industry) awards in the Product Design/Innovation category. We are extremely pleased and congratulations to our collaborators Pavilion Architecture without whose vision and tenacity the project would not have moved forward in the way it did. The awards are announced on the 9th October at the Grosvenor House Hotel, London.
Working in collaboration with the staff and students of Oxford Brookes School of Architecture we are prototyping the new Forum sculpture, a 4metres high by 25metres long installation which is to be built within the courtyard of the new Abercrombe building. The structure is to be a series of aluminium plate boxes following the lines of principal curvature along a looping form. By breaking down the surface in this way we are able to simplify the geometry into simple elements folded out of a flat planar shape. More development is needed, particularly of the joints, but we are encouraged by the behaviour so far. The Forum sculpture will be built early Autumn 2013.
Duncan Horswill and Mark Pniewski represented Ramboll Computational Design at the 4th Annual Building Envelopes Asia conference in Singapore on the 17th and 18th April.
The conference is in its fourth year and brings together 25 world class speakers to discuss cost efficient design as well as engineering and material technologies for high performance building envelopes.
Together Duncan and Mark used the work of the team to demonstrate the advantages of a computational approach to the design of complex glass envelopes. The presentation drew on our experience of working with complex architectural geometries on projects such as the Astana National Library in Kazakhstan and the National Holdings HQ building in Abu Dhabi to demonstrate the inherent issues with the application of traditional facade solutions to complex surfaces and how, with the help of computation, we can meet these challenges.
As well as the above case studies we will be presented our latest research which has been developed over the past four years in collaboration with the University of Bath, the EPSRC and AG5 Architects in Copenhagen to develop a digital design strategy which allows the designer to experiment with novel form whilst retaining an underlying engineering and construction logic. This work is at the cutting edge of its field and combines dynamic 3D modelling with genetic programming and analytical tools to create a virtual environment where building forms evolve from the bottom up as a result of the requirements of the designers, client and site.
Harri Lewis and Stephen Melville of the Ramboll Computational Design team presented their paper ‘ TRADA Pavilion – Searching for Innovation and Elegance in Complex Forms Supported by Physical and Software Prototyping’ (authors Harri Lewis, Stephen Melville and John Harding) at the the Prototyping Architecture conference at the Building Centre, London. An e-book of the conference papers can be downloaded here
The KREOD, a temporary exhibition space designed by Pavilion Architecture and Ramboll Computational Design, has won the best temporary structure at the 2013 Surface Design Awards.
The Surface Design Awards recognise progressive design and the use of innovative surfaces in design projects, both in the UK and internationally. The awards also highlight the wealth of creativity and innovation in the industry.
KREOD is a sustainable, portable, demountable and multi-functional indoor or outdoor exhibition space. The project was led by Pavilion Architecture with its organic form inspired by nature, resembling a seed.
The structure sits on castors, allowing the structure to be moved and rearranged into different forms and spaces to create a versatile event space with practical considerations for transportation, storage, disassembly and reassembly.
The structure is made up of three reciprocal timber gridshells that implement a number of geometrical optimisation and fabrication algorithms that have not been previously applied to a real structure. The form is a creative response to the need for a building that can be easily erected and subsequently demounted by hand, uses Kebony timber – a previously untried material – of a given size and limited thickness, and had to be delivered within a strict budget.
Using digital technology to its fullest, KREOD was delivered in a collaborative manner with each member of the design team understanding the innovative work and challenges of the other contributors and designed accordingly.
The awards were presented at the Surface Design Show, which took place at London’s Business Design Centre.
John Harding and Harri Lewis of the Ramboll Computational Design team recently gave a talk on ‘Finding Form: Embedding materiality in Computational Design’ at the Materials, Tectonics and Structures Colloquium at the University of Nottingham School of Architecture. The talk was well received and generated a lively debate.
Working with Architects Innovation Imperative, Ramboll Computation Design have helped with digital fabrication advice and structural analysis of a small and potentially adaptable ‘garden office’. Tetra Shed is a free standing single-storey timber structure designed to create an architecturally striking and comfortable space that can be internally adapted to suit the unique requirements of every client whilst maintaining the same structure. Expected uses are as a home office, extended living space or commercial applications.
The structural frame builds upon the expertise Ramboll Computational Design have developed in the CNC fabrication and jointing of thin ply sections on the London Funnel and Trada Pavilion projects
In this unique project the client, digital film distributor Arts Alliance, wanted a lightweight, easily transportable venue to house its new performance of ID: Identity of the Soul on a worldwide tour. The brief required a structure that would meet the technical requirements for video projection and surround sound during live performances, as well as accommodating up to 3,500 people without impeding views of the stage. The structure had to be capable of being erected within two weeks and when demounted it had to fit inside a reasonable number of shipping containers for transportation across the world. It also had to be of the highest architectural quality.
Oslo-based practice, Various Architects proposed a dynamic oval form within an inflatable hexagonal PVC outer skin and drum-like fabric roof. Together with specialist contractor ESS, we developed a structural concept that has met the challenge.
After evaluating a number of different structural options an arrangement of radiating spokes, akin to the wheel of a bicycle, formed by tension cables running between inner and outer steel ring beams supported on steel lattice columns was chosen. The resulting structure is ultra-light, easily transportable and quick to assemble, whilst providing a large, clear space for the theatre area.
The exterior skin is self-supporting and consists of a web of inflatable fabric tubes coated in PVC, with translucent inflatable pillows as infill. To help generate the hexagonal pattern of the pneumatic skin, Generative Components software was used to parametrically control the size and scale of the hexagonal tessellations.
The Arts Alliance theatre is believed to be the largest mobile entertainment venue in the world measuring 90m by 40m on plan and in 2008 won the Spark Award.
Rambøll Computational Design (RCD) and artists Loop.ph have completed the design and erection of a 6m tall carbon fibre and perspex arch structure for Belvedere Vodka’s RED street party in New York, USA.
Taking over Manhattan’s Meatpacking district with a dramatic light show and music, the event was a one of a number of international celebrations in the run up to World AIDS Day on 1st December. World AIDS Day was first ever global health day, providing an opportunity to unite in the fight against HIV, show support for people living with it and commemorate those who have died from the disease.
Guests watched the area become illuminated in red against a backdrop of 20ft white neon trees to helpBelvedere Vodka and (RED)™ raise awareness of the campaign to eliminate the transmission of the HIV virus from mothers to their babies and achieve the first AIDS-free generation born by 2015.
The teams worked intensively for a month and collaborated on parametric 3d models in order to develop a form initially based on a flat pattern of 85 number, thin carbon fibre rods which was then warped and twisted to give the shape a natural stiffness. Perspex ribs linked the carbon rods together to ensure that the sculpture acts as coherent entity. The carbon fibre rods acted as natural conductors powering LED lights fixed in the corporate logo of Belvedere Vodka. Rambøll Computational Design provided structural engineering, 3d modelling, construction advice and practical assistance.
Just an hour before the production deadline, the Loop.ph and RCD teams finished assembling the structure and were able to pivot it into its final position. Shortly afterwards the New York public filled the square off Gansevoort and Hudson Street, milling around and under the arch, for a set by electro-funk DJs Chromeo to promote the cause.
Both the Trada and KREOD pavilions have been shortlisted for the Surface Design awards in the temporary structures category. The awards are announced on the 7th February 2013. Full details can be found here
A full size trial erection of one of the plywood timber legs of the Trada Expo pavilion will be exhibited at the Prototyping Architecture Exhibition in Nottingham starting 17th October.
The trial was undertaken to test the stiffness of the reciprocal support panels, the ease of erection, quality of finish and the effect of adding edge stiffeners upon the overall performance of the structure under accidental load. It proved an extremely useful exercise, validating the time and effort expended in ordering and building the test leg. It will be accompanied in the exhibition by a 1:10 scale model of the pavilion, built to assess the potential modes of failure.
Ramboll’s Trada Pavilion, a plywood structure inspired by the efficient curved forms of Frei Otto and Heinz Isler, was unveiled to the public for the first time this week at the Timber Expo 2012. The exhibition is the premier show in the UK for all those involved in the timber sector.
Trada commissioned Ramboll’s computational design team to design the timber pavilion, which was the focal point of the Timber Expo 2012 stand and one of the biggest draws at the exhibition. After this exhibition, the sculpture will showcased again on TRADA’s stand at the 2013 Ecobuild exhibition.
The team set themselves the challenge of creating a planar three-valent mesh approach for the double curved surface, rather than the conventional triangular mesh. A hexagonal mesh has the advantage of fewer connections and greater structural efficiency, but requires coding from scratch and a great deal of research. The final design utilizes techniques from the computer game industry coupled with engineering intuition.
Based on the team’s previous research into funicular form finding, the design uses weak springs to automatically generate a zero bending moment surface, enveloping a large trade stand and allowing the public to circulate underneath. It uses a mesh of thin plywood plates joined via simple expressed hinged pin connections. The structure was modelled with the extensive use of generative 3D systems with the output linked to a CNC router.
The KREOD (formerly known as Dpod) pavilion, located at the North Greenwich Olympic site, has now been completed – a significant event as it marks the culmination of a challenging design and fabrication process.
KREOD is a sustainable, portable, demountable and multi-functional indoor or outdoor exhibition space that will be installed in multiple locations within London. The project is led by Pavilion Architecture with its organic form inspired by nature, resembling a seed.
KREOD will sits on castors allowing the structure to be moved and rearranged into different forms and spaces to create a versatile event space with practical considerations for transportation, storage, disassembly and reassembly.
The structure, which has taken some time to come to fruition, is made up of three reciprocal timber gridshells that implement a number of geometrical optimisation and fabrication algorithms that have not been previously applied to a real structure. The form is a creative response to the need for a building that can be easily erected and subsequently demounted by hand, uses Kebony timber – a previously untried material – of a given size and limited thickness, and had to be delivered within a strict budget.
Using digital technology to its fullest, KREOD has been delivered in a collaborative manner with each member of the design team understanding the innovative work and challenges of the other contributors and designing accordingly.
KREOD will be launched and unveiled to the media today at its current site, adjacent to the North Greenwich Arena in East London, where it will remain for six weeks before being moved to its next site.
Stephen Melville of Ramboll’s Computational Design team has been invited to speak at the Den Kloke Tegning (The Smart Drawing) in Oslo on 25th October 2012. Details are here: http://www.denkloketegning.no/
John Harding of the RCD team together with Sam Joyce, Paul Shepherd and Chris Williams of the University of Bath has been selected to present a paper on Thinking Topologically at Early Stage Parametric Design at the Advances in Architectural Geometry conference in Paris, September 27-30.
John Harding’s current EngD topic looks into the inflexibility of parametric modelling software for the early stage of design. By using techniques in genetic programming (GP), a new way of working with parametric models is proposed. The idea was recently published at the Advances in Architectural Geometry Conference in Paris. Abstract:
“Parametric modelling tools have allowed architects and engineers to explore complex geometries with relative ease at the early stage of the design process. Building designs are commonly created by authoring a visual graph representation that generates building geometry in model space. Once a graph is constructed, design exploration can occur by adjusting metric sliders either manually or automatically using optimization algorithms in combination with multiobjective performance criteria. In addition, qualitative aspects such as visual and social concerns may be included in the search process. The authors propose that whilst this way of working has many benefits if the building type is already known, the inflexibility of the graph representation and its top-down method of generation are not well suited to the conceptual design stage where the search space is large and constraints and objectives are often poorly defined. In response, this paper suggests possible ways of liberating parametric modelling tools by allowing changes in the graph topology to occur as well as the metric parameters during building design and optimisation”
A Preprint of the paper can be downloaded here here
Harding, J. and Derix, C., 2011. Associative spatial networks in architectural design: Artificial cognition of space using neural networks with spectral graph theory. In: Design Computing and Cognition ’10. New York: Springer Science and Business Media, pp. 305-323.
Paper presented at the International Association for Shell and Spatial Structures Symposium, 2011. Abstract:
“This paper describes a new method for the form-finding of funicular structures in two or three dimensions using a zero-length spring system with dynamic nodal masses. The resulting found geometry consists of purely axial forces under self-weight, with zero bending moment at nodes for both shells and tension net forms. A real-time solver using semi-implicit Euler integration with viscous damping is used to achieve system equilibrium. By using a real-time solver, the designer is able to alter the gravitational field or apply new point loads without re-starting the analysis, leading to an interactive experience in generating design options. The advantages of this method over existing approaches are discussed, with its successful application in a recent real case-study project also shown.”
With input from several Architectural practices in Denmark we are currently working on an application which models and evaluates alternative commercial tower typologies in real-time, giving instant performance feedback during the early design stages where the most important decisions are made but also when the least amount of time is available.
Evaluation criteria include solar gain, heat loss, structural performance, gross floor area, etc… as well as site specific impacts such as shadow casting of neighbouring buildings. This quantitative performance data (which can be numerically optimised) is then combined with the qualitative aspects of design such as aesthetics, social impact, iconography, etc. when making informed decisions in how to progress the design. Different modes of representation including physical models are also implemented to allow integration with existing tried and tested methods of working.
As the design space is so large at concept design stage, modelling variations in different tower ‘types’ has meant us going beyond traditional optimisation of numerical sliders in parametric models, and as a result this has opened up interesting avenues of research.
As part of the feasibility study into the most efficient structure for a dome over two hundred metres in diameter Ramboll Computational Design built upon and refined the techniques developed for the Tallinn Town Hall roof project. A double skin stick and node structure is automatically generated within the semi sphere volume first using the physical properties of a gas and then electrical repulsion to locate every node the same distance apart thus making every structural element the same length. This technique can be adapted to free form shapes and our software also allows for structural feedback and automatic reconfiguration to suit the stress distribution within the frame.
The design for the roof structure of the roof of a National museum in North Africa used our own software to automatically generate efficient funicular forms by dynamic relaxation. The components of the roof were thus uniformly tensioned, use a minimal amount of material and benefit from the visual harmony of repeatable section profiles throughout the space.
Our competition entry for the headquarters and research building of a large corporation in Finland exploited the ideas first postulated by Pier Luigi Nervi at the Gatti Wool factory in 1953. Lines of principle stress are joined to form ribs in the soffit of a reinforced concrete flat slab. The volume of concrete is reduced in comparison to a ‘conventional’ reinforced concrete slab, reducing emboddied carbon and enhancing the thermal mass characteristics. The exposed lines of structure are an expression of the reaction of the frame to external load. We have written our own software to model the stress vector field and resulting downstand ribs.
Our pavilion for Trada is progressing with a deadline of 11 weeks until it has to be built and ready to receive the public. The structure is proving to be incredibly complex for an installation of only 6m by 8m on plan and made even more challenging due to the decision to adopt a planar hexagonal mesh for the double curved surface rather than the conventional triangular mesh. A hexagonal mesh has the advantage of fewer connections and greater structural efficiency but has required coding from scratch and a great deal of research. The final design uses techniques from the computer game industry coupled with a great deal of engineering intuition.
The D_pod pavilion took a step closer to reality recently with the completion of the joint testing at Cambridge University. The pavilion has changed a great deal since the first iteration back in 2010. The mesh is hexagonal rather than quadrilateral meaning a different approach has been needed to the engineering of the joints in order to keep them cheap, to use the material on hand and to give them a ‘furniture like’ appearance. RCD specified a reciprocal joint fixed with hidden bolts, which because the Kebony timber was being used for the first time in a load-bearing structure had to be validated by testing. After several tweaks to the detailing we are glad to report that the connections performed as hoped and it’s straight into construction in time for the opening at the Greenwich Olympic site in June.
As part of his role as a part time Structural Engineering tutor at Oxford Brookes School of Architecture, Stephen Melville will be giving a lecture on Thursday 2nd February on the subject ‘Structuring Architecture’. This is a great opportunity to help convey the principles of collaboration and critical thought in the overlapping space of Architectural Design and Engineering Optimisation.
Stephen Melville recently gave a lecture to the Architectural faculty of the Technical University of Delft on Computational Design and the practical application of the RCD team’s on-going research to live projects and future directions such as urbanism. The lecture was at the invitation of the high rise unit of the school.
With Texere Studios, this was the first time we applied the research into digital urbanism and the science of emergent behaviour. taking the free roaming ponies in the new Forest as a inspiration for a traffic calming measure in a london site we helped with a design which created an inner city farm with sheep instead of horses.
Working with Foster + Partners we developed an in-house routine to automatically determine the optimum three dimensional roof form giving the right degree of internal solar shading in the new villa structures on the coastline of Montenegro.
The application automatically shapes the roofs of villas in relation to the solar shading needed. We were able to prove to Foster + partners the absolute minimum of roof overhang needed for this purpose.
A number of different parametric design tools were then used to set map the structure in an efficient manner on the doubly curved roof form such that the minimum amount of timber was used with the simplest orthogonal joints.
A least energy structure the form being determined by rcd’s own routines together with principle curvature mapping to form efficient framing
The timber members were set out in relation to the lines of principle curvature on the efficient surface. we developed the routines to do this and it enables a simple orthogonal structure to be set out on a complex surface.
Computational analysis of caternaries enhances 3D modelling capability
On a competition submission for Riga Airport, the RCD group used computerised analysis to model the undulating roof structure which was inspired by the catenary form. In the 19th century Gaudi defined the form of his iconic La Sagrada Família by making scale physical models using chains with hanging weights – catenaries.
In the case of the Riga Airport roof the form was found using the modern day computational technique of dynamic relaxation – a digital modelling tool ideal for analysing catenaries. The rationale behind Riga airport’s undulating roof surface was that it should dip where there are check-in desks and rise where natural light is needed to channel into the space below. At one end of the building the roof needed to drape down to the floor to create a sense of enclosure.
The initial geometry was created by the architect using some simple structural rules. Engineers then developed the geometry, maintaining the integrity of the shape but optimising the structural performance significantly using dynamic relaxation.
As a result the final design achieved the architects’ vision for an irregular curving roof while optimising the structure.
An algorithm inspired by electrical behaviour of sub-atomic particles rationalises a complex facade
Both archive and museum, the National Library will be a place for work and study, as well as education and tourism. A place for progress and a place for pleasure. As a national concentration of knowledge about the Kazakh culture and history, geography and demographics, government and presidency, the National Library will be a place for the people to learn about the president, as well as a forum for the president to meet with the people.
The initial scheme for the façade of the new Presential Library envisaged a triangulated diagrid of steel members set out in the form of a Möbius strip. If a ‘traditional’ rectilinear grid pattern were to be adopted for the setting out of the cladding panels then every panel and member length would be different making the façade package extremely expensive. The engineers’ challenge was to refine this complex and expansive steel façade structure to make it simpler and less costly to construct.
By applying an optimisation routine based on the theory of electrical repulsion engineers were able to refine the design so more panels were the same area and more supporting members were the same length.
The engineers created an algorithmic software script that ascribed to each nodal point in the facade a simulated electrical charge. Following the principle of electric repulsion, the nodes ‘repelled’ each other until they were evenly distributed, thus creating steel members of a standardised length.
A second algorithm was then used to push nodes towards areas of high stress, thus tuning the structure to the forces flowing within it, making it more structurally efficient.
Using digital intelligence to identify lines of principle stress in a structure.
For the competition-winning design of the new Greenland National Gallery the RCD group developed a reinforced concrete slab solution that looked original and striking while also being more energy efficient than a conventional reinforced concrete flat slab. The engineering design was based on extensive research into mapping stress flows through flat plate structures, using advanced digital tools. The concept uses new research into the actual stress flows through a flat plate structure and also revisits work from the early 1950’s by the great Pier Luigi Nervi.
Pier Luigi Nervi famously expressed the lines of principle stress in the reinforced concrete floor slabs of the Gatti Wool Factory. When he analysed the stress vector field, he used an intuitive approach based on trial and error.
The engineering team wrote a computer script to map stress flow pathways accurately and comprehensively. By mapping the principle stress vector field of a flat concrete plate with support locations based on the positions of columns in the building frame they were able to design a precisely calibrated slab, where slab thickness varies according to the structural requirement. When the stress flow paths are expressed in reinforced concrete they create elegant, curved, ribbed structures.
Computational analysis optimises uniquely curved form
D-Pod is a multi-use temporary grid shell structure. The architect’s original design (created using parametric software) posited each member as both curving and twisting. However, elements are often easier to fabricate if they are curved in one direction only. Connection detailing is also easier to standardise and therefore less costly if the curvature occurs only along one plane.
The engineering team created a digital tool to reveal the lines of principal curvature in real time to the designer. The architect was able to assess the curve network aesthetically before deciding on a final surface form.
Applying this curvature network constraint early made it easier to remove the twist effect and simplify connections once the design was finalised.
To make the shape of the grid shell more structurally efficient, the engineers morphed the underlying surface into a new position using a self-written script that integrated with the parametric software. Applying the principal curvature tool from the previous exercise to each new surface ensured the resulting structure was buildable.
The new town hall for Tallinn, the capital of Estonia, is a structure composed of 13 intersection boxes, the largest of which is a 60m tall tower comprising the main council
chamber and 37m high lightweight glazed façade. A deep roof structure incorporating a staircase to take visitors to a viewing arcHitect platform was required and as a result the
RCD team developed a tool for finding the most efficient way of fitting structure to the irregular volume of the roof void.
As well as providing support against wind and snow loading, the roof serves to prop the high side walls and huge glazed façade allowing lateral forces to be transferred to the stability core at the rear of the structure.
The tool that was developed used a routine that served to release a specified number of nodes into the volume. Each node is then given a simulated electrical charge so that they repel each other. When the nodes find an equilibrium position they are all an equal distance apart and members are drawn between adjacent points. As such a triangulated structure is derived where all members are of equal length. Engineering judgment was then used to refine the structure in areas of high or low structural density.
Algorithm mimics natural selection to evolve optimal structure.
The new town hall for Tallinn, the capital of Estonia, is a structure composed of 13 intersecting boxes, each of which cantilevers a considerable distance from inset columns at ground floor level. The side walls of each box are blank and therefore provided the opportunity to hide the arcHitect supporting cantilevering trussed frames.
The RCD group used the theory of genetic design to evolve and engineering solution that went beyond the traditional structural typology of a truss to deliver a more
The genetic algorithm was originally developed by John Holland in the 1960s and is a computer simulation of Darwinian evolution.
The engineers’ genetic algorithm solver initiated a population of possible truss arrangements which were assessed against a performance-related fitness criterion – in this case the deflection of the trussed frame. The resulting solution, which could not have been intuited using guesswork or traditional engineering assumptions, is the best optimised solution that effectively reduces deflection.