Numerical Simulation And Experimental Study Of Self-piercing Riveting With Elliptic Pipe Rivet

With the rapid development of automobile industry, automobile economy beingincreasingly high demand, lightweight has become the inevitable direction of development ofenergy-saving cars. In the manufacturing process, the use of aluminum alloy, magnesiumalloy and high strength steel and other lightweight materials are the most effective ways toreduce the body weight. As for the joining of lightweight materials, spot welding is almostpowerless, self-piercing riveting is essentially a young and efficient cold forming process. It isgetting more and more attention and being favoured by automotive industry.In this paper, a new type of mechanical joining method:self-pierce riveting process withelliptic pipe rivet is investigated comprehensively. It doesn’t required pre-drilled holes in theself-piercing riveting process, which can join two or more layers of sheet material.Simultaneously, it is no smoke, simple operation and easy to automate while riveting. Afterthe connection of metal sheet, it not only can product the smooth joining surface of rivetingjoint, but also obtain good quasi-static strength and fatigue strength. By using the technique ofnumerical simulation and experiment research, the effect of different process parameters onjoint performance of self-piercing riveting are studied. The studies have been carried out inorder to optimize the riveting parameters and obtain the optimal joint property.Finite element numerical simulations of self-piercing riveting with elliptic pipe rivet arecarried out by DEFORM-3D software. Forming process of the riveting, distribution of stressand strain, variation tendency of load-displacement curve, and flowing trend of metal materialare analyzed. Based on the theory of metal plastic forming technology, the influences of rivetmaterial, height, radial rate and other parameters to joint profile quality have been explored.Different parameters of elliptic pipe rivets are designed and manufactured.Tensile tests oflap joints, coach peel joints and cross joints with different parameters of elliptic pipe rivets arecarried out, measuring the shear strength, tearing strength and peeling strength. Through therange analysis and variace analysis method, the effect of different parameters on joint qualityis discussed. The results showed that, there is a primary and secondary order among theinfluence factors, sequencing for rivets wall thickness, height, radial rate, rivet placementform, thickness of sheet material to rivet end angle. At the same time, the optimalcombination of factors are obtained, cross-section quality and failure mode of the rivetingspecimens are analyed and summarized.