외력에 의한 용접 잔류응력의 변화 측정

초록

Welding generates residual stresses in welded structures. Residual stresses play a significant role in the estimation of fatigue lifetime of welded structures. Therefore, it is important to understand the behavior of residual stresses under applied loading. In this study, a SM490A plate, 480x80x5t, with welded center part was prepared. Welding residual stresses were measured using strain gauges. The cutting method was used. Then the variation of the residual stresses under applied tensile loading was measured. It was found that the residual stresses were relaxed in proportion to the magnitude of the applied loading, and relaxed in proportion with the magnitude of the applied loading, and under certain magnitude of loading, initial tensile stress changed to compressive stress.