Nick Cole, Robert Bird Group
Using Topology Optimisation to Produce Enhanced Concept Designs As engineers and designers, we are regularly presented with concept design challenges, from choosing the best structure for a long span roof or high rise lateral stability system down to selecting the best secondary steelwork arrangement to support a cladding system. C O N C E P T U A L A S S I S TA N C E
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o make these choices we rely on two main tools:
Our intuition – Much like meeting a new person, much of our decision-making process is carried out in the first few moments that we are presented with a new problem. We ‘see’ solutions to the problem at hand and instantly set about planning them. Our intuition is honed through the combination of our academic teaching and our professional experience and we like to think that as both our training and experience increase, so too does our intuitive ability. Fig.2. Draw the most efficient truss system within the bounding box for the load and supports
Our analytical nature – As designers we naturally like to analyse solutions to find optimal ways of tackling problems. Our approach to ‘analysis’ is often quite rigid, constrained by the fact that the basis of our analysis (geometry, intended load paths, structural arrangement) is pre-determined by our intuition. The analysis tools available to us are typically able to give very accurate answers to the very specific questions that we ask them allowing us to create optimal solutions within the original constraints. However, our analysis tools are typically not capable of telling us that we asked the 16 • CONCEPTUAL ASSISTANCE
wrong question in the first place or that our engineering logic was flawed. This article, and subsequent presentation at Stålbyggnadsdagen (7th November 2019), will look at how Topology Optimisation can enable structural designers to deliver optimal solutions, offering material savings over our intuitive ‘text book’ responses to engineering problems. Before you read on, I have a question for you. Please look at the image in Fig.2. and, with a pen, draw the most efficient (minimum weight/ maximum stiffness) simply
supported truss geometry for the load/ supports shown, staying within the bounding box. This could represent a column transfer truss in a high-rise building. This question has been chosen as one of the most basic structural systems that we all come across – a simply supported truss – with a trivial loading condition. We would expect our intuition to lead us directly to the optimal solution for something as basic as this. I have asked this question to over 100 practicing structural engineers from fresh graduate to N R 3 • 2 0 1 9 • N Y H E TE R OM STÅ LB Y GGN A D
