Topologically optimised facade brackets: an embodied carbon, structural and residual stress analysis

Abstract

The research investigates the topological optimisation of the metal brackets that connect curtain wall panelling to the floor slabs of a building. As is typically the case with standard building components, the brackets are overdesigned with higher load margins than real applied loads. Optimising them results in reduced mass and a more evenly spread stress distribution. Correspondingly, the question that the project asks is whether the optimised designs have a comparable structural performance to the standard bracketry used in construction, and a lower embodied carbon. To answer this, several optimisations of a standard facade bracket are performed, resulting in a total of six converged design options, with three of them progressed for fabrication. The manufactured designs are then horizontal and vertical load and residual stress tested to assess their performance, and an embodied carbon analysis is performed to calculate the corresponding emissions for raw material extraction, processing, and component fabrication. The results indicate the presence of compressive yield magnitude residual stresses, and that structural performance is comparable to a standard bracket, but embodied carbon is in most cases higher. The paper concludes with a discussion of the findings, and possible next steps in the optimisation, structural testing, and embodied carbon analysis workflow.