Modeling buckling distortion of DP600 overlap joints due to gas metal arc welding and the influence of the mesh density

This paper presents a computational framework for the modeling of buckling distortion of I mm thick DP600 overlap joints due to gas metal arc welding. The results have been compared to experiments and show good agreement. The simulations have been repeated for various FE meshes and different linear finite elements. It is shown that not only the distortion amplitude but also the buckling mode is mesh-dependent. In order to explain this behavior, an eigenmode calculation of the first two modes is undertaken as a basis for comparison and shows that the geometrical stiffness of the finite elements has an influence which is also dependent on the expected buckling mode. It is shown that for an adequate model of the expected distortion, a fine resolution is required everywhere where bending is to be expected. Dependent on the buckling mode, this could hold for the whole structure. However, it is also shown how the computation time can be reduced significantly for a controlled loss in accuracy by optimizing the FE mesh. (C) 2009 Elsevier B.V. All rights reserved.