Topology Optimization Using the SBFE-BESO Approach for Composite Structure Design

Abstract

This paper presents a topology optimization method that integrates the image-based Scaled Boundary Finite Element (SBFE) method with the Bi-directional Evolutionary Structural Optimization (BESO) algorithm. The approach targets composite structures composed of multiple materials, each exhibiting distinct mechanical properties under tension and compression. The structure is partitioned into tension and compression regions using the first invariant of the stress tensor, derived from the sum of the diagonal (or principal) stresses. Materials optimally suited for each stress state are then selectively assigned to their corresponding regions. Engineering structures are used to demonstrate the method's effectiveness. Results indicate that the proposed approach enhances structural performance, improves material utilization compared to single-material optimization, and reduces overall material volume, contributing to cost efficiency.