Size effect on crack kinking in a piezoelectric strip under impact loading

• Crack kinking phenomenon in a piezoelectric strip is investigated.
• Full singular fields around the crack tip are obtained asymptotically.
• Mixed-mode crack may tend to kink out of the original crack plane.
• Crack kinking angle depends on the hoop stress intensity factors (HSIFs).

An impermeable crack in a piezoelectric strip under in-plane mechanical and electric impact loading is considered. The crack is located at an arbitrary position and parallel to the surfaces of the piezoelectric strip. Fourier and Laplace transforms are applied to reduce the mixed-mode crack problem (modes I and II) to a system of singular integral equations. Full singular fields around the crack tip are obtained asymptotically in an explicit form and the hoop and shear stress intensity factors are determined. Laplace inversion is applied to get the mechanical and electrical fields in the time domain. The crack kinking phenomenon is investigated by applying the criterion of maximum hoop stress intensity factor. Numerical results show that the geometry of the cracked strip and the electric loading significantly influence the singular field distributions around the crack tip. Mixed-mode crack may tend to kink out of the original crack plane, and the crack kinking angle depends on the distribution of the hoop stress around the crack tip and the maximum value of the hoop stress intensity factors (HSIFs).