Multi-material topology optimization involving simultaneous structural and thermal analyses

Traditionally, the design of building envelope components is primarily focused on meeting technical requirements rather than finding optimal design solutions. New components are typically generated using numerical models validated by experiments, and the general methodology mainly consists of extensive numerical parametric studies. Since the basic geometrical shape is chosen beforehand, it is not possible to know if an optimum is reached. In view of this, topology optimization has emerged as a new design technique which offers much more design freedom. In this work, topology optimization is used to simultaneously improve the mechanical and heat transfer characteristics of building components. The first study shows that using a density-based method intermediate densities can constitute part of the optimized solution and the choice of certain parameters in the interpolation functions becomes influential. The second study presents a multi-material topology optimization approach in which an additional predefined material is added to the optimization problem. The results of both studies are compared. Finally, a practical case is optimized using this multi-material, multi-physics approach, and an optimized brickwork support bracket is found. Results show that a combined structural and thermal topology optimization approach with multiple materials can provide interesting and innovative design solutions.