Topology Optimization Method of Structures with Surface Corrosion Considered

Engineering equipment served in harsh environments for a long time will inevitably corrode, resulting in a loss of mechanical performance and a reduction in a lifetime, and even threatening production safety. Although conventional post-treatment anti-corrosion technologies can slow down the corrosion rate, it is important to consider the corrosion effect on the structural performance in design. This paper proposes a topology optimization method with prior consideration of structural corrosion resistance during the design phase, so the structures designed by the approach can have excellent corrosion resistance, considerably reducing the cost of post-treatment anti-corrosion technologies. First, an erosion-based method is utilized to identify the structural surface layer. In the procedure, the initial structure is eroded to generate a reduced-scale eroded structure, and then, the eroded regions are specified as the surface layer. Second, dual-material interpolation is used to create the corrosion model by modifying the material properties of elements on the structural surface layer, which is set to 0 to simulate uniform corrosion. Finally, the topology optimization method with structural surface corrosion considered is enforced through a two-step filtering/projection process. After the entire lifetime corrosion analysis, various numerical examples indicate that the structural performance of the proposed method is superior to that of the standard method (SIMP interpolation) without considering the influence of corrosion, demonstrating the effectiveness of the proposed method.