How to obtain diverse and efficient structural designs through topology optimization

Topology optimization techniques are widely used to maximize the performance or minimize the weight of a structure through optimally distributing its material within a prescribed design domain. However, existing optimization techniques usually produce a single optimal solution for a given set of loading and boundary conditions. In architectural design, it is highly desirable to obtain multiple design options which possess not only high structural performance but also distinctly different shapes and forms. Here we present three simple and effective strategies for achieving diverse and competitive structural designs, including (i) penalizing precedent designs, (ii) using constraints as design drivers, and (iii) introducing randomness into structural models. These strategies are successfully applied in the computational morphogenesis of a variety of structures. The results demonstrate that the developed methodology is capable of providing the designer with structurally efficient and topologically different solutions. The structural performance of alternative designs is only slightly lower than that of the optimal design. This methodology holds great potential for practical applications in architecture and engineering. The examples shown in this study are based on the bi-directional evolutionary structural optimization (BESO) technique. However, the proposed strategies are general and would be applicable to other commonly used topology optimization techniques.