温度依存型界面要素を用いた溶接高温割れのモデル化とFish Bone型高温割れ試験への応用

抄録

Based on the interface element proposed for crack propagation problems, a finite element method (FEM) using a temperature dependent interface element is developed. The proposed method is applied to the analysis of the formation and the propagation of hot cracking in welding. In particular, the hot cracking extending from the starting edge of the narrow trapezoidal plate under bead welding is examined using the proposed method. In case of the trapezoidal specimen with welding from the narrower side, the crack length becomes longer when the welding speed and the heat input is large. This agrees with the phenomenon observed in experiments. In case of the specimen with welding from the wider side, the welding speed and the heat input influence in the opposite manner. Further, the effect of the parameters involved in the proposed method on the computed phenomena is closely examined. Through this study, it is found that the hot cracking simulated by the proposed method is mainly influenced by the BTR (Solidification Brittleness Temperature Range) and the scale parameter r₀. This agrees with the concept proposed by Matsuda through high temperature ductility curve.