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.
