Study On The Mechanical Properties Of The Self-piercing Riveted Joints Of Dissimilar Thickness Aluminium Sheet Materials

The automotive vehicle weight affects directly vehicle fuel consumption and exhaust emission in the automotive industry. Hence lightweight vehicle become one important means to improve fuel economy and emission standards. The light magnesium aluminum alloy and fiber reinforced plastic material are widely used. The traditional connection method is difficult to connect these materials. As a unique connection technology of self-piercing riveting(SPR) can connect them effectively.The paper was based on the 5052 aluminum alloy single-lap self-piercing riveted(SPR) joints of dissimilar thickness connecting, the tensile and fatigue properties of the joint was studied based on the test and simulation, and the mechanical properties of the joint influenced by the thickness was comparatively analyzed. Some work and study achievement were obtained. The main work of the paper can divide into the following several parts:1. The SPR process of the dissimilar thickness aluminum alloy sheet was studies, and the optimal SPR process parameters of the 1.5mm+2.5mm combination of 5052 aluminum alloy SPR joint(AB joint) was obtained. The finite element simulation of the SPR process of the joints was studied, the result was shown that the test and simulation had a good consistency.2. The study of the static mechanical properties of the joint based on the test and simulation.The quasi-static mechanical properties test was adapted to test the AB joint, the load-displacement curves and the static failure process with failure mode of the joints were acquired. Different thickness connection of the same materials of the joints were comparatively studied, the result showed that the static strength of joints would increase with the increasing sheet thickness. The study of the finite element simulation of the AB joints showed that AB joint got the same static failure mode with the test.3. The study of the fatigue properties of the joint based on the test and simulation.The fatigue properties test was adapted to test the AB joint, the S-N curves and the fatigue failure process with failure mode of the joints were acquired. Different thickness connection of the same materials of the joints were comparatively studied, the result showed that the fatigue strength of joints would increase with the increasing sheet thickness. The study of the finite element simulation of the AB joints showed that AB joint got the same fatigue failure mode with the test in the high load level, but it should do some further research when it was in the low load level.