EFFECT OF CONTACT MODEL ON NUMERICAL SIMULATION OF FRICTION STIR WELDING
接触模型对搅拌摩擦焊接数值模拟的影响

Two contact models, the classical Coulomb contact model and the modified Coulomb contact model, are used in a fully coupled thermo-mechanical numerical model of friction stir welding, and the suitabilities of the two models to simulate the welding process are analyzed. Results indicated that there are little differences between the numerical results of the two contact models for friction stir welding in low rotating speed. In high rotating speed, the classical Coulomb contact model fails due to no limit of shear stress at the interface, but the modified Coulomb contact model may be used. The increase of the rotating speed does not change the nature of solid joining in friction stir welding. When higher rotating speed is adopted, the deformations on the top and bottom surfaces of the weldment become more similar, which led to more uniform microstructures.