Directed evolution-based non-gradient method for structural topology optimization

Existing non-gradient optimizers often rely on stochastic search strategies, which require a large number of finite element analyses to evaluate the objective function. In this study, a directed evolution-based non-gradient topology optimization method is proposed to reduce the high computational cost. A directed generation strategy of load path components is presented, based on the idea of fixed-point enumeration. This strategy determines the position and direction of components by locating the region with the maximum stress and enumerating samples with different orientations at each iteration step. Then, an element removal criterion is developed to gradually eliminate the redundant elements from the components. Consequently, an adaptive adjustment technique of component size is presented to overcome the numerical instability. The applicability and effectiveness of the proposed method are illustrated through numerical examples. The results show that the proposed method can reasonably generate structural load paths with exceptional efficiency compared to existing non-gradient algorithms.