The efficiency of the element removal or addition is of significance for evolutionary structural optimization (ESO) process. The key is to find an appropriate rejection criterion (RC) which allows to assess the contribution of each element to the specified behavior（stress, stiffness, displacement, etc.）of the structure, and to subsequently remove elements with least contribution. This paper proposed a varying elements removal ratio (VERR) method which uses a larger ERR (Element Rejection Ratio) value at early iterations where exist a lot of redundant material, and decreases the value of ERR in the optimal process to lessen the number of elements removed at later iterations. Meanwhile, this paper proposed a strategy for element addition based on stress level and the contribution of elements to the structure in order to decide which elements should be added to the model and the sequence of the element addition. With the proposed VERR and the strategy, the optimization procedure of the structure evolves more quickly and smoothly.
Improved Bi-Direction Evolutionary Structural Optimization Method and Its Application
