Development of 3D Finite Element Method for Hot Cracking Using Interface Element and Its Application for Pear-shaped Bead Cracking Under Narrow Gap Welding

Abstract

The objective of this research is to develop a 3D finite element method (FEM) for hot cracking using temperature dependent interface element. Proposed method can predict the formation and extension of hot cracking. It includes Iterative Substructure Method (ISM) which can reduce the computational time with keeping high accuracy.
In this study, proposed method is applied to the problem of pear-shaped bead cracking under narrow gap welding. The applicability and the validity of the method are verified through serial computations. The computed results show that proposed method can simulate pear-shaped bead cracking and surface cracking which are distributed along the longitudinal cross section in welding line. Additionally, it is found that when the weldment is penetrated to the back of plate, pear-shaped bead cracking is difficult to form. The computational speed of the method using ISM increases by about 7 times faster than the method which doesn't use ISM.