Experimental and numerical investigation of the vibration stress relief process on a T- shape welded joint

Thermal and vibration stress relieving processes are among the common methods of reducing residual stresses that can be performed on the part after the manufacturing. The advantages of vibratory stress relief over thermal stress relief are no need for fixtures, time and cost savings, no weight and dimensional limitations and usability for all alloys. In this research, the numerical and experimental study of vibration stress relief process of a T-shaped weld has been done. In the first step, a T-joint was made using shielded metal arc welding . The longitudinal and transverse residual stresses equal to 251 MPa and 191 MPa were measured, respectively. The differences between the calculated and the measured residual stresses in the longitudinal and transverse direction are about 17% and 1.5%, respectively. Then, by finite element simulating the vibration stress relieving process, the optimal values of the parameters affecting the process, such as the frequency of force exertion, the amount of force and the location of force exertion, were obtained. The most effective vibration stress relief condition related to the case with the applied force equal to 20% of the yield force of the sample and the excitation frequency equal to 95% of the natural frequency of the sample. The differences between the calculated and the measured residual stresses after vibration stress relief process is about 10%. By increasing the applied load frequency to 95% of natural frequency of the sample, longitudinal and transverse residual stresses decreased by more than 55% and about 70%, respectively.