Abstract:Due to their excellent characteristics of light weight, high specific strength/stiffness, and good vibration and energy absorption, truss lattice structures have been widely used in the design of key load-bearing components of spacecraft. However, in view of the numerous topological configurations and significant difference in mechanical properties of truss lattice structures, the traditional empirical design method cannot achieve an optimal configuration under complex load conditions, and failing to meet the urgent performance requirements of ultra-lightweight and high load-bearing for high-end equipment. This paper proposes an intelligent design method of truss lattice structures with free configuration by two design strategy of fast restarting intelligent algorithm and deleting lattice struts. Firstly, a geometric parameterization model of a lattice unit cell is constructed by the explicit topological description function, achieving independent description of each strut of the lattice structures. Secondly, an energy homogenization method is employed to calculate its macroscopic effective properties of a lattice unit cell, to further perform efficient mechanical performance analysis for lattice structure. Finally, taking the geometric description parameters as design variables, allowable material usage as constraint conditions, and the overall compliance minimization of lattice structures as objective functions, an optimization mathematical model for lattice structures is established. And then an efficient surrogate-assisted particle swarm optimization algorithm is adopted to solve the above optimization model. To address the issue of traditional ESPSO algorithm tending to fall into local convergence, a fast restart strategy is applied to improve ESPSO algorithm, enhancing its global search capability. And to further expand the optimization space of ESPSO algorithm, a lattice strut deletion strategy is also designed, improving the design flexibility of lattice topological configurations and maximizing the material utilization rate. Numerical example results show that the proposed design method can significantly enhance the load-bearing capacity of truss lattice structures, and also provides a theoretical reference for the design of lattice structures for high-end equipment.