The influences of the cyclic force magnitude and frequency on the effectiveness of the vibratory stress relief process on a butt welded connection

Abstract

Welding residual stresses are considered as significant factors for the reduction of fatigue life and load bearing of welded structures. In this article, characterization of a low-temperature stress-relief method called vibratory stress relief process was investigated. In this regard, welding of a butt joint of two steel plates was simulated and induced welding residual stresses were calculated. An experimental residual stress measurement was conducted to verify the numerical results. It was established that the simulated residual stresses are in good agreement with the measured results obtained from the hole drilling strain gauge measurements. In the following, the vibratory stress relief process of the welded joint was simulated using finite element method (FEM). It was observed that by controlling the process parameters, a notable reduction in the residual stress is achievable. Effects of magnitude and frequency of the cyclic force on the effectiveness of the stress relief process were studied. The results indicated that by increasing the applied load frequency up to 95% of the natural frequency, the longitudinal residual stress decreased more than 80%. Also, it has been shown that by increasing the force magnitude, the welding residual stresses were reduced drastically.