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Description
Clinching, as a versatile joining process capable of bonding different sheet materials, is widely used in the automotive industry to meet the demand for lightweight structures. Consequently, understanding and improving the fatigue strength of clinched joints is of significant importance. Accurate fatigue life prediction during the design phase can help reduce costs and minimize safety risks.
However, simulating the fatigue life of clinched joints in a 3D model for millions of cycles until failure is computationally prohibitive due to the high costs associated with modeling contact mechanics between the metal sheets. Recent research has proposed an alternative approach: computing the stress distribution of a 3D model for a single cycle and applying the stress history of the element with the highest von Mises stress to Lemaitre’s two-scale damage model to predict fatigue life. While this method significantly reduces computational effort, since only one element is simulated to failure, it overlooks the evolution of stresses and strains in the entire structure.
To address these limitations, this study introduces a 2D substitute numerical model that incorporates the effects of friction between sheets and thermal influences. The proposed model eliminates the need to fully simulate contact mechanics by implementing a slip condition on the internal surface of the upper sheet. This simplification balances computational efficiency with physical accuracy.
In this work, the 2D numerical model is first described in detail. The model is then validated against experimental data to ensure its reliability. Finally, the influence of friction and thermal effects on fatigue life is investigated through a series of test cases, highlighting the model’s predictive capability and potential applications.
