Structural optimization and experimental study on the Ti-alloy Kagome structure formed by the superplastic forming/diffusion bonding process

The structural optimization of Ti-alloy lattice structure formed by the superplastic forming/diffusion bonding (SPF/DB) process is a high-nonlinear problem with multiple design variables. The problem is solved in this research by introducing the modified Kriging response surface model based on structural mechanics analysis and the genetic algorithm into the optimization design of the Kagome structure. The comprehensive influence of the structural parameters on the shape and compressive strength of the structure is analyzed, and the optimized structural parameters are obtained. The SPF/DB forming and performance test of the optimized Kagome structure are carried out for verifying the accuracy of the model. The results show that the modified Kriging response surface model of the Kagome structure performs well in describing the relationships between the structural parameters and the simulation results, the average relative error of the predicted groove depth and compression strength are 2.4% and 4.5%, respectively. The specific compression strength and the specific compression modulus of the optimized Kagome structure are 5.21 x 10(4) N . m/kg and 1.50 x 10(6) N . m=kg. Based on the compression strength results calculated by the Kriging model, a new Ashby plot for the compressive strength as function of density is obtained.