Steel-aluminum plastic clinching of an inclined wall die

To solve the problems of low-strength and unsatisfactory connection quality in the plastic clinching of heterogeneous lightweight materials for car bodies, Q235 steel sheets and 5052 aluminum alloy sheets were selected as research objects. An inclined wall die for plastic clinching was designed on the basis of the deformation and flow characteristics of sheets in the plastic clinching process. Elastic-plastic finite element numerical simulation and experimental research were conducted to analyze the plastic clinching process of the inclined wall die, and the failure mode and mechanism of the clinching joints in the shear and peel experiment were comprehensively studied. Results showed that the inclined wall die can effectively increase the interlock value of the joints and reduce the maximum joining force during the clinching process under the condition of ensuring the neck thickness of the joints. When the inclined wall angle alpha increased from 90 degrees to 100 degrees, the interlock value increased by 38.9%, and the maximum joining force decreased by 8.3%. The influence of the inclined wall structure on joint quality can be divided into the extrusion, radial inflow, and stability stages. The comparison between the clinching experiment and the finite element results showed that the results are in good agreement, proving that the finite element model of the plastic clinching of the inclined wall die exhibits a high degree of credibility and verifying the feasibility of the practical application of the inclined wall die. Finally, the major failure mode of the joints under shear and peel loads was separation failure.