Large-scale Analysis of Welding Deformation and Residual Stress Problem by Idealized Explicit FEM Using Iterative Substructure Method

In order to establish the method to analyze the welding deformation and residual stress of the whole structure, the authors have developed a new analysis method called Idealized Explicit FEM (IEFEM). In this paper, Iterative Substructure Method (ISM) introduced IEFEM is proposed to achieve larger scale computation. The proposed method was applied to simple girth weld problem of a pipe and analysis results were compared to those by the existing method. As a result, it was found that the proposed method has the almost same analysis accuracy as the existing method. Computing time and memory consumption were also investigated and it was shown that the proposed method can analyze large scale problem in dramatically shorter computing time and less memory consumption compared to those of the existing method. In addition, the proposed method was applied to the large scale problem of the welding process of the canister of high level radioactive waste. Analysis results were compared to measured experimental results and it was found that the results obtained by the proposed method and measured were in good agreement. And it was also found that the proposed method can analyze the large scale problem having more than 3 million degrees of freedom in realistic time.