Optimisation of Complex Geometry High-Rise Buildings based on Wind Load Analysis

Abstract

Wind analysis for the structure of buildings is a challenging process. The increasing strength and frequency of wind events due to climate change only add higher demands. In addition, high-rise buildings are growing in number and include many of unconventional shape. Current methods used in practice for calculating structural wind response either do not account for these geometries, such as the Eurocode or are prohibitively time-consuming and expensive, such as physical wind tunnel tests and complex Computational Fluid Dynamics simulations. As such, wind loads are usually only considered towards the end of design. This paper presents the development of a computational method to analyse the effect of wind on the structural behaviour of a 3D building model and optimise the external geometry to reduce those effects at an early design phase. It combines Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA), and an Optimisation algorithm. This allows it to be used in an early design stage for performance-based design exploration in complement to the more traditional late-stage methods outlined above. The method was implemented into a rapid and easy to use computational tool by combining existing plugins in Grasshopper into a single script that can be used in practice on complex shaped parametric high-rise building models. After developing the method and testing the timeliness and precision of the CFD, and FEA portions on case study buildings, the tool was able to output an optimal geometry as well as a database of improved geometric options with their corresponding performance for the wind loading allowing
for performance-based decision-making in the early design phase.