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Simulation on Residual Stress Field for Aluminum Alloy 7050-T7451 of Ultrasonic Rolling Process

Ultrasonic rolling is a process of intense plastic deformation rolling under the action of a composite energy field formed by normal static pressure and high-frequency ultrasonic shock coupling. The technology can effectively improve the surface quality of parts. Proper residual compressive stress and its distribution on the machined surface can effectively improve the fatigue strength and corrosion resistance of the workpiece, and then prolong its service life. Applying the finite element software, the contact model of ultrasonic rolling process was built to simulate the ultrasonic rolling process of aluminum alloy 7050-T7451, and the distribution of equivalent plastic strain and residual stress distribution were analyzed effectively. The simulation results showed that ultrasonic rolling process on surface can lead to the more drastic plastic deformation and residual compressive stress. Meanwhile, with the increase of the depth from surface, the residual compressive stresses decreased gradually and easily transformed into residual tensile stress. Eventually, the two stresses can reach the internal balance. All the situational results are agreed with the experimental data, although with a small deviation. It can provide technical support and theoretical basis for optimizing the ultrasonic rolling process parameters.