Numerical investigation of singularity at a vertex in 3D transversely isotropic piezoelectric bonded joints by FEM

Stress singularity at the vertex of bonded joints is one of the main factors responsible for debonding under mechanical or electrical loading. The distribution of stress singularity field near the vertex of bonded joints is very important to maintain the reliability of intelligent materials. Piezoelectric materials are being widely used in the electronics industry, due to their high piezoelectric performance. In this paper, stress singularity at vertex in 3D transversely isotropic piezoelectric bonded joints is analyzed. Eigen analysis based on FEM is used for stress singularity field analysis of piezoelectric bonded joints. The Eigen equation is used for calculating the order of stress singularity, and the angular function of elastic displacement, electric potential, electric field, stress and electric displacement. The numerical result shows that the angular functions have large value near the interface edge than the inner portion of the joint. It was observed from the result, that the possibility of debonding and delamination at the interface edge of the piezoelectric bonded joints, due to the higher stress and electric displacement concentration at the free edge.