Abstract: The residual deformations and the stresses after plug welding of a thin-wall cylinder with an inner bearing of compressor are analyzed by 3-D thermal-elastic-plastic FEM. The local coordinate system and the reduced integration method are introduced in order to increasing the accuracy of calculation. The eccentricity of the bearing and the radial deformations at the end of cylinder are analyzed for various cases with different conditions of plug welding. The calculated results are compared with the measured values and good agreement is obtained. These simulations provide the possibility to predict the effects of various parameters on welding deformations and to control it to maintain high accuracy of the compressors. The residual stresses after plug welding are also calculated. The results show that the maximum principle stresses appear in the heat affected zone which is around the plug welds and reach high values.

Key words: Compressor, Finite element method, Residual stress, Welding deformation