Application and practical validation of topology optimization technology for the frame of biaxial tensile testing machine

Abstract

Biaxial tensile testing machines are used to improve accuracy of yield loci and constitutive model for sheet materials. The frame of these machines is the main load-bearing structure significantly affecting the machine accuracy. However, the available loading frames are too heavy to be practical for popularization and application. To reduce both the total weight of the frame and install consumption, this study develops a design method of stepwise multi-stage topology optimization based on the solid isotropic microstructures with penalization (SIMP) method. First, the validity of the finite element model during the optimization is verified by experiments. Next, the design method of stepwise multi-stage topology optimization is proposed based on the results of conventional topology optimization and the influence law of key parameters. This method is then applied to the topological optimization design of frames for a biaxial tensile testing machine. Finally, the optimized frame is manufactured, and biaxial tensile tests are conducted on the designed machine. The measurement of frame deformations shows that the frame weight is decreased by 19.5% compared with that of the initial design and that the frame stiffness meets design requirements. These results prove the effectiveness of the proposed method.