In the analysis of welding mechanics, it is difficult to analyze largescale structures because of welding-specific moving local nonlinearity. In this research, the authors developed a new analytical method for welding mechanics, named Idealized Explicit Finite Element Method (IEFEM). In the proposed method, the temperature step is divided into hundreds of time steps as implicit FEM and the displacements are computed for each time step based on dynamic explicit FEM until the whole system reaches the static equilibrium state. And, to achieve the static equilibrium state faster, idealized mass and damping matrix is introduced. The idealized mass and damping matrix are based on the Courant condition and the vibration theory, respectively. The proposed method and static implicit FEM are compared at the final path of multilayer welding of thick bead-on-plate to verify validity and accuracy. The transient and residual deformation and stress distribution of the proposed method show good agreement with those of static implicit FEM. In addition, the computing time and memory consumption of the proposed method are 1/12 and 1/40 times shorter than those of static implicit FEM, respectively, in 243,243 degree of freedom model. It is found that the proposed method has an advantage in large-scale analysis whose nodal points are more than tens of thousands.
In recent years, due to the remarkable improvement of computing and analysis technologies, numerical analysis methods such as the finite element method (FEM) have been utilized to examine the mechanical behavior of practical structures (Zhang, Jin, Qi and Guo 2008). Numerical analysis enables us to understand engineering problems in advance. Therefore, numerical analysis is used not only for research but also for production designs. However, in welding problems, the computational size of PC-based numerical analyses is usually limited to the welding joint level.
