Effect of Welding Heat Input on Residual Stresses at the Corrugated Interface of Aluminum/Steel Composite panels

This study investigates thick aluminum/steel composite panels featuring wave-flat composite interfaces. This study employs a thermo-mechanical sequentially coupled numerical simulation method to systematically analyze the influence of welding thermal cycles on the temperature distribution and residual stress patterns at the interface.By establishing a finite element analysis framework based on the Goldak double ellipsoid heat source model, the spatiotemporal evolution characteristics of temperature and stress during the welding process were revealed.The simulation results closely match the experimental measurements, validating the reliability of the model.The results indicate that the residual stresses along the thickness direction are primarily governed by the welding heat input.When the heat input increased from 11,232 J/cm to 22,464 J/cm, the peak residual stress in the thickness direction rose by 164%.Excessive heat input leads to overgrowth of brittle intermetallic compound (IMC) layers at the aluminum/steel interface, significantly weakening the interface's tensile pull-off strength and tensile shear strength.This study elucidates the mechanism by which welding thermal cycles influence the thermo-mechanical coupling response at the aluminum/steel composite panel interface, providing theoretical foundations and engineering guidance for optimizing composite panel welding processes and enhancing their in-service performance.