Journal of Research in Mechanical Engineering and Applied Mechanics ISSN: 3107-4510 (Online)

Authors : Md. Shahidul Islam, Hideo Koguchi

Abstract : In recent years, intelligent or smart structures and systems have become an emerging new research area. Piezo-ceramics material, due to its characteristic direct-converse piezoelectric effect, has naturally received considerable attentions. The stress concentrations caused by mechanical or electric loads may lead to crack initiation and extension, and sometimes the stress concentrations may be high enough to fracture the material parts. Stress singularity of bonded joints is one of the main factors responsible for debonding under loading. However, the stress singularity for transversely isotropic piezo-ceramic bonded joints has not been made clear until now. In this paper, order of singularity and intensity of singularity in piezo-ceramic bonded joints is analyzed. Eigen analysis based on finite element method is used for order of singularity analysis of the joints. The distributions of stress and electric displacement in the singular field for the piezo-ceramic bonded structure are obtained by using the boundary element method. It is shown from the numerical result that the stress and electric displacement increase with the thickness of upper material and have larger value near the vertex of the interface. Therefore, there is a highest possibility to debond and delamination occurs at the corner of thick transversely isotropic piezo-ceramic bonded joints.

Keywords : Bonded joint, Boundary element method, Eigenanalysis, Piezo-ceramic, Stress singularity.