Numerical simulation of buckling in welding thin panels.

摘要

Thin welded structures are extensively used in many industries. Using numerical modeling to predict and control of welding distortion of thin structures, especially buckling due to welding, is therefore important. This dissertation presents a non-linear finite element (FE) study on the welding distortion and buckling of thin panels, using an optimized three-dimensional (3D) FE code, WELDSIM. Several related issues in buckling control are discussed, and several remedies are proposed.; The WELDSIM analyzes transient and residual fields of temperature, stress and distortion of welded structures, through a de-coupled formulation of the nonlinear heat transfer and elastic-plastic thermo-mechanical boundary value problems with large strains. Special features to improve the accuracy and efficiency in welding simulation integrated into the code WELDSIM are discussed. The code was verified by practical examples in the areas of heat transfer, stress analysis, and welding simulation.; As a special application, WELDSIM was then applied to model the welding buckling tests done at the Edison Welding Institute. It demonstrated the capability of WELDSIM to handle complicated models for welding induced buckling, which have 60,000 degrees of freedom and long welding duration. Buckling due to welding could be mitigated by optimizing welding parameters with WELDSIM, such as reducing heat input, increasing restraints or reducing initial imperfection of panels to be welded.