Numerical investigation of the influence of heat source modeling on simulated residual stress distribution in weaving welds

摘要

The influence of the modeling of the weaving of a heat source on the simulated residual stress distribution was examined. Two types of heat source models, "weaving" and "quasi-weaving," were used. The former modeled the weaving directly, and the latter simplified the weaving heat source to a wide and straight-moving one. When the weaving heat source was used, fluctuating temperature histories, wave-like fusion lines, and serrated residual stress distributions were obtained. Three different quasi-weaving heat source models have different combinations of the heat flux value per unit volume and the elements to which the heat source was introduced. The temperature distributions around the welds were different depending on quasi-weaving models used. However, when the temperature distributions of the weaving welds could be reproduced precisely by a quasi-weaving model, smoothed temperature histories and residual stress distributions were simulated, and the values obtained were comparable to those obtained with the weaving model. On the other hand, when the temperature distribution was not well reproduced, the residual stress distribution did not agree with that of the weaving model. The results suggest that the modeling of a weaving heat source using a quasi-weaving model requires adjustment of the temperature distribution.