Abstract
In heavy industrial fields such as power plant and chemical plant, it is often necessary to restore a damaged part of large machinery or structure which is installed in the hazard working place. In this paper, to evaluate the safety of plastic deformed cylindrical beam a finite element technique has been used. The variations of residual stresses on the process of damaging and restoring for surfaces and cross-sections have been examined. The results show that the maximum von Mises stresses occur outer cylinder surfaces of boundary between cylindrical beam support md cylindrical beam when deformation procedure and restoring force is applied. The maximum residual stress remains 158.6MPa in the inner wall and this value correspond to $53\%$ of yield stress then restoration procedure is finished.