Analysis of singular stress fields at junctions of multiple dissimilar materials under mechanical and thermal loading

Traditional finite element analyses of the stress state in regions with dissimilar materials are incapable of correctly resolving the stress state because of the unbounded nature of the stresses. A finite element technique utilizing a coupled global (special) element with traditional elements is presented. The global element includes the singular behavior at the junction of dissimilar materials with or without traction-free surfaces. A hybrid global (special) element is developed utilizing the exact solution for the stress and displacement fields based on the eigenfunction expansion method under mechanical and thermal loading. The global element for arbitrary geometrical and material configurations, not limited to a few dissimilar material sectors, is interfaced with traditional local (conventional) elements while satisfying the interelement continuity. The coupling between the hybrid global element and conventional finite elements is implemented into ANSYS, a commercially available finite element program. Also, the global element is integrated into the ANSYS graphical user interface for pre- and post-processing.