Multi-Material Topology Optimization in LS-TaSC™ Using Ordered SIMP Interpolation

Topology optimization allows for the design of structures with an optimum distribution of material for a given set of load cases that may have conflicting requirements. Though the methods used in topology optimization help to generate better and novel designs, they are generally limited to a single material only. In contrast, modern vehicle structures are composed of parts made of multiple materials, exhibiting usually superior performance compared to single-material designs. In order to support the design process of such structures, this problem requires the ability to use multi-material optimization methods within commercially available software like LS-TaSC, to optimally distribute multiple materials within a single design domain. In this paper, a method for integration of the ordered SIMP in LS-TaSC to realize multi-material TO is proposed and evaluated using a solid beam that is subject to static and crash load cases. The optimization uses the updated material distribution, based on ordered SIMP, to assign material/density values to elements in the design domain. To demonstrate the potential of the multi-material TO and validate the results, the obtained topologies are compared to single material designs as well as to the structures optimized using the state-of-the-art gradient-based approach based on ordered SIMP. The results show that LS-TaSC can be successfully used for deriving multi-material structures superior to the single-material designs. Finally, due to the low computational costs, the method seems to be suitable for the optimization of large-scale industrial models.