Failure modes of mechanical clinching in metal sheet materials

Abstract The failure modes of clinched joints in metal sheet materials are comprehensively studied. The clinched joint failure modes are defined and classified into four types: neck fracture, hybrid neck fracture, hybrid button separation, and button separation. A forming factor c , which is calculated from the cross-sectional parameters of a clinched joint, is presented as a coefficient associated with the joint failure modes. The clinched joint's mechanical properties and different failure modes with varying c values are then studied. The conclusions were also verified by experiments using different materials. The joint that undergoes hybrid failure has excellent load-bearing capacity and energy absorption ability because of the combined characteristics. The appearance, variation, and disappearance of the hybrid failure modes are parabolic and controlled by the forming factor c . Clinched joint failure modes of similar materials can be approximately inferred by the forming factor c. Thus, the forming factor c can be used as a reference to control the clinched joint's mechanical properties.