Integrated optimization framework for multi-domain assemblies A novel polygon topology to non-matching meshes and materials

Current traditional topology optimization primarily focuses on single-domain design, practical engineering structures often require multi-domain assemblies with geometric complexity, material heterogeneity, and localized load demands. This paper proposes a novel polygon topology optimization framework of assemblies, addressing the need for adaptive mesh strategies across subdomains. The proposed approach overcomes key limitations of traditional single-domain optimization by enabling seamless integration of non-matching meshes with diverse material properties through subdomain-specific discretization. The framework automatically enforces compatibility at interfaces without remeshing by utilizing S-elements of Scaled Boundary Finite Element Method (SBFEM) to connect different mesh types while maintaining equilibrium. A generalized node-to-node coupling scheme is employed to handle multi-material interfaces, accommodating both anisotropic and isotropic material combinations. The method incorporates an efficient SIMP-based optimization with subdomaindependent volume constraint. Adaptive mesh strategies further enhance computational efficiency relative to uniform mesh method, as demonstrated in practical applications such as automotive floor frame. By eliminating ad-hoc post-processing, the framework provides a unified workflow from mesh assembly to optimized design. Numerical examples confirm the method’s effectiveness in handling variable mesh densities, practical assembly constraints, and complex geometries structures.