A model is presented in this article to investigate the dependence of effective magnetostriction of the magnetostrictive composites on the parameters of components including the elastic modulus, permeability, and volume fraction, etc. Concentrating on the two-component magnetostrictive composites and choosing the two components to be general magnetostrictive materials, this model yields, analytically, the effective magnetostriction of composites by means of the method of complex potential. In terms of the analysis of this model, the magnetostrictive composites can be roughly divided into two kinds. One kind is that the matrix material is nonmagnetic or a material with very low magnetostriction, in which the effective magnetostriction is independent of the permeability of components. Another kind is the case in which the two components have close magnetostriction, and the effective magnetostriction of the composites generally depends on the elastic and the magnetic parameters of both components and the volume fraction. Unlike the first kind of composite, in a certain range, effective magnetostriction of this kind of composite can be improved by increasing the permeability of matrix. In addition, dependence of the effective magnetostriction on the other parameters of the components has also been discussed systematically. To evaluate the accuracy of this model, comparisons are made between the theoretical values and the experimental results published in the literature, which indicate that predictions of this model agree qualitatively with the experimental data.

In this article, we study the effective elastic and plastic properties of particle-reinforced composite mterials with imperfect interface. The imperfect interface is described by a spring-type model assuming that the traction conitnuity remains intact, while the displacement experiences a jump proportional to the interfactial traction. Both the tangential and normal displacement discontinuities at the interfaces are considered and the effective elastic moduli are obtained using a generalized version of dilute model, self-consitent model, Mori-Tanaka model, and efferential model. A comparison between the effective elastic moduli obtained by these different models is made and the determination of an effective plastic behavior of particulate composite materials, by means of the Mori-Tanaka model and secant moduli method, is also discussed. Finally, we examine the influence of interfacial compliance on the macrossopic averaged mechanical properties of composite materials.

A moving screw dislocation in a transverselyisotropic piezoelectric material is investigated in detail. The analytical expressions for displacement, electric potential, stresses, electric displacements, strains, and electric fields are obtained.When the velocityof the dislocation is zero, or when the piezoelectric constant is zero, the results derived in this paper can reduce to known results.