Welding residual stresses are one of the main factors influencing the engineering properties of welded structures, and should be taken into account during designing and manufacturing different products such as ships, bridges, etc. The contour method is one of the new powerful stress measurement techniques that is used for measuring residual stresses. In this method a welded component is cut normal to the weld line. Displacements normal to the cut surface are measured. Using the finite element method (FEM), residual stresses before the cut are then reconstructed from the measured displacements. However after cutting the part of interest, only displacements normal to the cut surface can be measured while in-plane displacements cannot be measured. Therefore, the main objective of this paper is to examine the influence of in-plane displacements on the quality of reproduced residual stresses using numerical simulation. In this paper, a computational approach is developed to numerically simulate the contour method. Welding residual stresses are evaluated when conventional and low transformation temperature (LTT) weld wires are used. Phase transformation is considered for LTT welds. The developed computational approach is then used to simulate the contour method and reconstruct the residual stresses using 1) both normal and in-plane displacements, and 2) using only normal displacements. Simulation results show a very good agreement between welding residual stresses as originally computed and the reproduced stresses when in-plane displacements are considered. Additionally, application of only the displacement normal to the cut surface; reproduces stresses with a good agreement with welding residual stresses and those reproduced considering in-plane displacements. |
