High Resolution Topology Design with Iso-XFEM

Topology optimization, as a challenging aspect of structural optimization, has gained interest in recent years as a method of designing structures to take advantage of the design freedoms of advanced manufacturing techniques such as Additive Manufacturing (AM). The majority of topology optimization algorithms are integrated with the Finite Element Method (FEM) to enable the analysis of structures with complex geometry during the optimization process. However, due to the finite element-based nature of the subsequent topology optimized solutions, the design boundaries are dependent on the finite element mesh used and tend not to have the desired smoothness for direct fabrication. The topology optimized solutions may, therefore, need smoothing, reanalysing and shape optimization before they become manufacturable. In this study, an Extended Finite Element Method (X-FEM) is employed and integrated with an evolutionary structural optimization algorithm, aiming to avoid/decrease the post-processing required from topology optimization design to manufacture. Rather than using finite elements for boundary representation, an isoline/isosurface approach is used to capture the design boundary during the optimization process. The comparison of the X-FEM-based solutions with the FE-based ones for the topology optimization of test cases representing real industrial components indicates significant improvements in the solutions’ boundary representation as well as their structural performance.