An iterative generative design approach for multi-material components

The lightening of the components is playing an increasingly predominant role in modern industry to create ever more sustainable machines, reducing energy consumption while increasing the performances. Indeed, components and subassemblies are usually made of multiple materials to satisfy the design requirements. The definition of the material lay-out within the component's could be a challenging process and may lead to sub-optimal designs. The proposed Generative Design approach faces this task with an iterative topology optimization based algorithm. Indeed, with the proposed approach it is possible to optimize the materials lay-out and their related inner interfaces within a specified design domain. The approach consists of a two level optimization method and it can consider also non-linear hyperelastic materials as in the case of automotive seats. The production of seats requires a large use of polyurethane foam, combined with plastic and/or metal frames. In particular, the car seats consist of different materials such as steel frame, filled polyurethane foam for seat cushions and vertical backrests, and external textiles. For the considered test case, the method here developed proposes an optimization loop to consider the influence of the polyurethane foam in the topological optimization of the plastic part of the seat, allowing the possibility to modify boundary regions between the different materials. This loop continues optimizing both material regions, achieving an optimized material distribution of the multi- material part.