Singularities at interface corners of piezoelectric-brass unimorphs

Abstract In this study, singularity fields at the interface corners of piezoelectric-brass unimorphs are investigated. Two models differing in side surface geometry (step and flat surfaces) are analyzed to study the singularity effect on mechanical (stress–strain) and electrical (electric potential and intensity) behavior. A mixed-mode mechanical boundary condition is applied for analyzing the realistic application of unimorphs, with normal force, shear force, and bending moment as internal forces. The conservative integral together with a three-dimensional finite element analysis is used to determine the intensity of singularity. There are three singularity terms at each vertex and singular line. All singularity terms are investigated in detail. Intensities of the singularities at the vertex and several points located on side surfaces (singular lines) are examined. Results show that the intensities of singularities for mixed-mode conditions differ from that of tensile load conditions. For mixed-mode conditions, the intensity of singularity must be calculated for all singularity terms. In addition, the stress singularity characteristics at the vertex may be described as a function of the singularities along the singular lines. These findings clarify the understanding of singularity at interface corners of piezoelectric-brass unimorphs and may be used as references for developing relevant piezoelectric devices.