考虑铸造约束的空间结构节点拓扑优化设计研究

Aiming at the design problem of high-performance spatial structural nodes considering castability for industrialized batch production, a continuum topology optimization method integrating casting constraint was introduced to conduct the concept design of typical spatial structural nodes. An optimization model for minimizing the strain energy of the nodal domain (equivalent to maximizing nodal stiffness) was established under multi-loading conditions, which simultaneously considers casting and material volume constraints. To improve the design performance, threshold projection technology was used to suppress the generation of a large number of intermediate-density elements caused by density filtering. The optimization program was implemented through MATLAB. Comparative research was conducted on the topology optimization of spatial structural nodes with or without casting constraint, using the classic 3D four-ear plate spatial structural node as the design object. And the effects of different filtering radii, loading conditions, material volume, and meshes on the optimized design were evaluated. The results show that the traditional optimization method cannot ensure the castability of the optimized design of spatial structural nodes, and the casting constraint consideration is a necessary and feasible method to solve this problem. Reducing the filtering radius and increasing the amount of material will help enhance the design stiffness of the optimized nodes. Refining the finite element mesh can improve the design quality of nodes, but it will significantly increase computational costs.