Research on material flow in flat clinching process and joint failure mechanism

Abstract

Flat clinched joints are gaining popularity in lightweight and innovative engineering structures. This study aims to analyze the material flow in the flat clinching process and joint failure mechanism. Al5052-H32 aluminum alloy sheets were joined using flat clinching with varying forming loads. A finite element model was developed to study the material flow. Metallographic observations and microhardness measurements of the joint cross-section were conducted to investigate the material flow. Shear tensile and cross-tension tests were performed to analyze the influence of forming load on joint mechanical behaviors. Fracture surface analysis reveals joint fracture mechanisms in the cross-tension and shear tensile tests from microscopic and macroscopic perspectives. The results show that the most active material flow occurred in the upper sheet region near the punch fillet. Joint fracture exhibited ductile characteristics caused by the aggregation of micropores.

Keywords

flat clinching / clinched joint / material flow / mechanical behaviors / failure mechanism

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