Stress‐related topology optimization for castable design

Abstract

AbstractConsidering structural strength and castability in topology optimization is very attractive from the perspective of theory and application. This article introduces stress considerations into casting‐oriented topology optimization to explore structural optimization methods that simultaneously consider the above two vital design indicators. Two stress‐related topology optimization formulations for castable design are proposed and assessed systematically, namely, a compliance minimization with stress and casting constraints and a stress minimization with casting constraint. An effective optimization algorithm is developed to overcome various numerical difficulties caused by stress and castability issues in the solution. Particularly, a nonuniform threshold scheme along with the corresponding implementation algorithm is proposed to improve the casting constraint on irregular structures without appreciably increased computational effort. Benchmark examples are presented to discuss the numerical characteristics of the achieved designs and demonstrate the effectiveness of the introduced algorithms. This research illustrates the necessity and feasibility of stress considerations in casting‐oriented topology optimization. The results show that it is more appropriate to treat stress as a constraint rather than an optimization objective in the casting‐constrained topology optimization. The proposed formulations and algorithms allow designers to effectively achieve high‐performance castable designs with required structural strength requirements.