Joining thin-walled structures without protuberance by two-strokes flattening clinching process

Abstract

Clinching technologies have better performance in joining different sheet materials. However, the protuberance and mechanical behaviors of clinched joints have always been needed to be improved. In this paper, a new clinching method, named two-strokes attening clinching (TFC) process, was proposed to improve the mechanical behaviors of joints and atten the protuberance. Mechanical testing including tension shearing tests were employed under quasi-static conditions to evaluate the different mechanical behaviors between TFC and conventional clinched joints. The in uences of the different forming forces on mechanical response of these joints were studied. The static strength, energy absorption, material ow and failure modes of TFC and conventional clinched joints were investigated comparatively. The experimental results demonstrated that the tension-shear strength of TFC clinched joints was increased by 30.3% compared with conventional clinched joints at the forming force of 30 kN. Furthermore, the material ow analysis showed that the thickness and interlock of TFC clinched joints were increased by 79% and 45.9%, respectively. The energy absorption of TFC clinched joint was increased by 82%. In addition, the TFC process did not change the failure mode of clinched joints, and the failure mode of all clinched joints was neck fracture.

Evaluation of Shear and Peel Strength of Al1060 Single-Lap and T-Lap Joints Produced by Rotated Clinching Process with Twin Rotating Punches

“…They found that the shear strength and tensile strength were higher when the neck fracture occurred. Peng et al [15] conducted shear mechanical tests, cross-sectional profile measurements and failure mode analysis on two-stroke flat clinched (TFC) joints and clinched joints of Al1060 aluminum sheets. It was found that the neck thickness, interlock value, and shear strength of TFC joints are higher than those of clinched joints, and the failure modes are neck fractures.…”

Experimental investigation of high impact polystyrene/metal self‐piercing riveted joint

“…It could be concluded that the joint was subjected to tensile stress. Peng et al 11,12 proposed a reshaping method to decrease the bulge height of clinched joint. A flat die was utilized to compress the joint from die side and neck thickness of joint increased, resulting in larger strength of joint.…”