Optimization of Tetrahedral Lattice Structure under Multiple Loading Conditions

To address the difficulty of designing lightweight lattice structure, a parametric modeling method of lightweight lattice structure based on tetrahedral cell configuration is proposed, and a parametric mechanical simulation model of lightweight lattice structure is established. In order to improve the mechanical properties of lattice structure, the optimization method of lattice structure is studied. In this paper, the lightweight lattice structure specimen composed of tetrahedral cells is used as the object, and the lattice cell bar radius, length and inclination angle are set as design variables, maximize the stiffness of the specimen under compression and shear load, and at the same time minimize the mass of the specimen are set as the target to build the optimization model. In order to improve the efficiency of optimization, a response surface model is obtained based on the simulation model and the optimized Latin hypercube experimental design method. A response surface model is proposed to reflect the mapping relationship between the design variable and the objective function, and the accuracy of the model is verified. After then, the optimization problem is solved based on the agent model and the second generation non-inferior ranking genetic algorithm (NSGA-II), and the Pareto optimal solution set satisfying the design requirement is obtained and the appropriate solution is selected. Compared with the initial design scheme, it can be seen that the stiffness under compression and shear load are significantly increased, and the mass of the lattice structure is obviously decreased.