Dominant factors for high accurate prediction of distortion and residual stress generated by fillet welding

Angular distortion generated in fillet welding could be accurately predicted by regarding the weld metal as welds not assuming that the shape of welds was a simple triangular. By the way, in welding, the temperature largely changed from a melting temperature to a room temperature. So, mechanical properties of materials largely changed, too. Yield stress of structural steels becomes almost zero above 700 degrees C. The elastic-plastic analysis should be carried out satisfying the yield condition even at high temperature. It should be sufficiently recognized that welding distortion obtained by elastic-plastic analysis was not reliable if the yield condition was not satisfied above 700 degrees C. It was found that dominant factors for high accurate prediction of distortion generated by fillet welding were two factors (shape of welds and yield condition). The yield condition at high temperature above 700 degrees C was not directly influenced in the prediction of residual stress. Because residual stress was mostly produced in cooling stage below 700 degrees C.