NUMERICAL SIMULATION OF RESIDUAL STRESSES IN WELDED MONOSYMMETRIC I-SECTION AND COMPARISON WITH EXPERIMENTAL MEASUREMENTS

摘要

Localized heating during welding, followed by rapid cooling, can generate residual stresses in the welded metal. Estimating the magnitude and distribution of welding residual stresses is important. This study applied thermal elastic-plastic analysis, using finite element techniques, to analyze the temperature field and evaluate the residual stresses in welded monosymmetric I-section. Based on the ANSYS software, uncoupled thermal-mechanical three-dimensional (3-D) finite element model is developed. The heat source was provided by the heat generation rate. Meanwhile, the course of stuffing, melting, and freezing of the metal in welding seam was simulated by controlling death and birth of elements in the numerical calculation. The residual stresses at the surface of the weldments were measured by strain gauges. The results of finite element analysis (FEA) were compared with experimental residual stress data to confirm the accuracy of the method. The simulated results show that the 3-D model can be effectively used to simulate the thermal cycles and the welding residual stresses of the welded monosymmetric Isection. The distributions of the residual stresses are clarified, which indicate that the stress gradient in the web of the monosymmetric I-section is different from that of the double symmetric Isection.