An Inverse Approach for Constructing the Residual Stress Caused by Welding

In order to construct the residual stress fields existing in the structures caused by welding, the inherent strain, which is regarded as the source [1] of the residual stress, has been introduced to produce the residual stress fields fulfilling the self-equilibrium conditions. The assumed inherent strain field is adjusted to minimize the difference between the stresses calculated and the stresses measured. To assure the stability of the results in the inverse problem, the key-node method has been adopted here. The inherent strain has been assumed as a smooth function with some undetermined coefficients. The established experimental database and the knowledge can be used to assume more suitable strain field. To improve the accuracy of the FE analysis, the new element technique proposed by the authors [2] has been employed here. Finally, a numerical example has been employed to investigate the effectiveness of the present approach.