Jie-Cai Han

Investigation of a Griffith crack subject to anti-plane shear by using the non-local theory

Abstract Field equations of the non-local elasticity are solved to determine the state of stress in a plate with a Griffith crack subject to the anti-plane shear. Then a set of dual-integral equations is solved using Schmidts method. Contrary to the classical elasticity solution, it is found that no stress singularity is present at the crack tip. The significance of this result is that the fracture criteria are unified at both the macroscopic and the microscopic scales.

Electroelastic modelling of anisotropic piezoelectric materials with an elliptic inclusion

Theoretical work concerning the microstructural characterization and analysis of anisotropic piezoelectric media with inclusions is rather scarce, especially in comparison with numerous results and micromechanics models which exist today on the inclusion problem in anisotropic elastic media. In this investigation, the Stroh formalism is used to develop a general solution for an infinite, anisotropic piezoelectric medium with an elliptic inclusion; the coupled elastic and electric fields both inside the inclusion and on the boundary of the inclusion and matrix are given.

A penny-shaped crack in a transversely isotropic piezoelectric layer

In this paper, we develop a model to treat penny-shaped crack configuration in a piezoelectric layer of finite thickness. The piezoelectric layer is subjected to axially symmetric mechanical and electrical loads. Hankel transform technique is used to reduce the problem to the solution of a system of integral equations. A numerical solution for the crack tip fields is obtained for different crack radius and crack position.

Effect of Finite Cracking on the Magneto-electric Coupling Properties of Magneto-electro-elastic Composite Laminates

Magneto-electro-elastic composites can be developed in the form of a composite laminate by alternating the ferromagnetic layers and ferroelectric layers during stacking. Presence of interfacial crack may influence the magneto-electro-mechanical coupling behavior of magneto-electro-elastic materials considerably. This article establishes an analytical model for the analysis of interfacial crack problem in a layered magneto-electro-elastic medium. Unlike most existing studies, this article focuses on the magneto-electro-elastic laminate of finite size both in the thickness and the length directions. According to the boundary conditions, the mechanical, electric, and magnetic fields in the cracked magneto-electro-elastic laminate are formulated by singular integral method. The effect of interfacial cracking on the effective properties of the magneto-electro-elastic composites is studied. In addition, the crack tip field intensity factors are also given as they are not available in open literature.

Anti-plane analysis for elliptical inclusion in magnetoelectroelastic materials

This paper considers the multi-field coupling in magneroelectroelastic composite materials consisting of the inclusion and the matrix are magnetoelectroelastic materials. The mechanical, electric and magnetic fields around an elliptical cylinder inclusion are formulated by complex potentials. Inside the inclusion, the strain, electric and magnetic fields are found to be uniform and vary with the shape of the ellipse. When the inclusion is reduced to a crack, along the interface, the strain, electric field strength and magnetic field strength equal the corresponding remote ones, which can be used as the boundary condition. Special cases, such as a rigid and permeable inclusion, a soft and impermeable inclusion, a line inclusion and a crack problem are discussed in detail.

Thermal conduction in bi-layer materials with an interfacial inclusion

We establish an analytical model for a thermal inclusion in bi-layer materials. The inclusion is considered as either an elliptic filler of finite thermal conductivity or a crack of ideal thermal insulation. Unlike most existing studies, this article focuses on bonded media of finite size in both their height and the length directions. The temperature field is formulated by a singular integral equation method. The effects of inclusion size and interfacial cracking on the effective thermal conductivity of the medium are studied. In addition, the crack tip thermal flux intensity factors are also given as they are not available in the open literature.