Papers by Author: Z.Z. Zou

Abstract: The linear piezoelectricity theory is applied to investigate the dynamic response of coplanar interface cracks between two dissimilar piezoelectric materials subjected to the mechanical and electrical impacts. The number of cracks is arbitrary, and the interface cracks are assumed to be permeable for electric field. Integral transforms and dislocation density function are employed to reduce the problem to Cauchy singular integral equations. Numerical examples are given to show the effects of crack relative position and material property parameters on the variations of dynamic energy release rate.

Abstract: The problem of an interface edge crack between two dissimilar piezoelectric materials is analyzed under the conditions of anti-plane shear and in-plane electrical loading. The crack is considered to be traction-free, but electric permeable one across which the normal component of the electric displacement are continuous. A series form of electromechanical solution and field intensity factors are obtained. The results show that all fields including strain, stress, electric field strength and electric displacement are singular in the front of crack tip. At last, the stress intensity factor is solved by the boundary collocation method (BCM), numerical results are given and discussed.

Abstract: The dynamic anti-plane crack problem in a functionally graded smart structure is considered. Integral transforms are employed to reduce the problem to the solution of singular integral equations. Numerical results are presented to show the nfluences of electrical crack condition, crack position, electromechanical combination factor and material gradient parameter on the fracture behavior.

Abstract: The problem involving a center crack in a rectangular piezoelectric body under anti-plane mechanical shear loading and plane electrical loading is analyzed for the permeable crack face conditions. The so-called general solutions of stress and electric fields are obtained, which is satisfied both the governing equations of anti-plane problems and the boundary conditions of the crack face. It is shown that electric field is nonsingular near right crack tip, while strain, stress and electric displacement have crack-tip singular behavior, the energy release rate has the same form as that without the electromechanical interaction, which is always positive. At last, the boundary collocation method is used to calculate the energy release rate. Numerical values are obtained to show the influence of the material properties and the electric field. The results show that the method of half analytical and half numeral is simple, accurate and widely applicable.