Direct Load-Carrying Boundary Identification-Based Topology Optimization Method for Structures With Design-Dependent Boundary Load

Abstract

During topology optimization with design-dependent boundary load, updating the load conditions is necessary. However, it is challenging to identify the load-carrying boundary in density-based topology optimization frame. To address this issue, a direct load-carrying boundary identification method is proposed to describe and update the design-dependent boundary load, and a topology optimization method for structures with design-dependent boundary load is presented. First, a Flood Fill algorithm (FFA) based domain extension method is introduced to generate a new structure with a boundary equivalent to the load-carrying boundary of the original structure. Then, the erosion boundary identification method is applied to the new structure to identify the load-carrying boundary instead of the original structure. Finally, the load information (direction and magnitude) of the design-dependent boundary load is determined using a normalized gradient algorithm, which completes the update of the design-dependent boundary load. This method overcomes the difficulty of identifying the load-carrying boundary in density-based methods. The effectiveness of this method is demonstrated by several examples of minimum compliance (including 3D) and flexible mechanisms.