Boundary effect on crack kinking in a piezoelectric strip with a central crack

• Boundary effect on crack kinking in a piezoelectric strip is studied.
• Crack kinking is found for the impermeable crack other than permeable crack.
• Crack kinking angles have been predicted.

In this paper, the boundary effect on crack kinking in a piezoelectric strip with a central crack vertical to the boundary under in-plane loadings has been investigated. By using integral transform techniques the present mixed boundary value problem was reduced to the solution of dual integral equations, which can be further reduced to solving Fredholm integral equations. Analytical solutions can be obtained when the width of the piezoelectric strip are of infinite size. The asymptotic fields around crack tips have been provided for the electrically impermeable and permeable crack boundary conditions, respectively. Crack kinking phenomenon is investigated by applying the criterion of maximum hoop stress intensity factor. Numerical results show that the material properties, the geometry of the cracked strip and the electric-mechanical loading significantly affect the singular field distributions around the crack. Crack kinking is found for the impermeable crack case while no kinking for the permeable crack. Crack kinking angles for different piezoelectric materials under the impermeable crack surface condition have been predicted with certain loading and boundary conditions.