其他摘要：Residual stresses and plastic strains are produced by localized heating and cooling during welding. These stresses can lead to distortion and under certain circumstances even the premature failure of welded parts. Thus, residual stresses play an important role as far as the quality and reliability of a welded construction are concerned. Formation of distortions and residual stresses in weldments depend on many interrelated factors such as thermal and mechanical fields, phase transformations, material properties, structural boundary conditions, types of welding operation and welding conditions1, 2 In the present work, the previous finite element model developed by the authors3 to study the thermomechanical behavior of the solidifying metal in welding processes is validated using the analytical solution of Weiner and Boley.4 Also a kinetics based model was integrated into the same multiphysics finite element program to provide the time evolution of the microstructure.5 The material properties required for the non-linear thermomechanical analysis are temperature and phase dependent, and this dependency is accounted for by computing the microstructure evolution and using this information to estimate the material properties. This is done by assigning temperature dependent material properties to each phase and applying mixture rules to predict macro material properties. Finally numerical results are presented to illustrate the evolution of the stress field in a buttwelded joint.
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