Study on deformation behavior of clinching process for three-layer aluminum alloy sheets

To solve the problems of low strength and unsatisfactory connection quality of clinching in three-layer sheets, a method of clinching aluminum alloy three-layer sheets with an inclined wall die was proposed. AA5052 aluminum alloy sheets were chosen as the research objects. Elastic-plastic finite element simulation and experimental research were conducted to analyze the mechanism of clinching joints in three-layer sheets and a finite element method has been used to investigate and summarize the five stages of forming a three-layer aluminum sheet clinching. Six load distribution methods were designed to investigate the strength of clinching joints in three-layer sheets. The failure mode and failure mechanism of the joints in the shear and peel experiment were comprehensively studied. The comparison between the experimental and finite element results had an error of less than 8%, indicating that the finite element model was highly reliable. The failure strength of the joints and the energy absorption values were determined by physical experiments, and the results show that the D-2 joint has a maximum shear strength of 3400 N and an energy absorption of 6.67 J. The D-3 joint has a shear strength of 3040 N and an energy absorption of 9.29 J. The T joint has a lower strength and a higher failure displacement, with the T-3 joint having a maximum peel strength of 690 N and an energy absorption of 11.876 J.