Influence of clinching steps and sheet thickness on the mechanical properties of the clinching joint

In order to reduce the protrusion height and increase the strength of the clinched joint, a two-step clinching method was investigated in the present study. The whole process contains two steps. The first step is used to produce one-step clinched joints, and the second step is used to press the one-step clinched joints to reduce the protrusion height and increase the joining strength. The influences of clinching steps and sheet thicknesses on the mechanical properties of the clinched joint were investigated. The main failure mode of all the clinched joints in the strength tests is the neck fracture mode. The neck thickness can be enlarged by the two-step clinching method, and the protrusion height can be reduced. TCJ2.5-2.0 joint has the highest energy absorption and strength, and OCJ2.0-2.5 joint has the lowest energy absorption and strength. The two-step clinching process can contribute to increasing energy absorption and joining strength. For getting higher strength, the thick sheet should be taken as the top sheet. With higher strength and lower protrusion, the use of two-step clinched joint will be convenient in the mechanical engineering areas.