Research For The Effective Properties Of Irregular Shaped Inclusions Reinforced Composites With Imperfect Interface

Almost all of the research and design of composite materials has been concerned with the perfect interface. That means the interface is a mathematical surface across which material properties change discontinuously, while interfacial traction and displacement are continuous across the interface. The effective properties of composites are determined solely by the properties of constituent materials.To incorporate the property and structure of interface in the evaluation of effective properties of composites, a linear spring-layer of vanishing thickness is introduced to modeled imperfect interface, which assumes the displacements at the two sides of the interface become discontinuous and interfacial displacement jumps are linearly related to associated interfacial traction, while interfacial traction remain continuous for local equilibrium.The present paper is concerned with the solution for elastic field arising from an arbitrary convex polygon-shaped inclusion with uniformly distributed eigenstrains in an infinite elastic body having the imperfect interface. Firstly, the similar problem with perfect interface is considered. Based on the Rodin's algorithm, the elastic fields in a polygon-shaped inclusion with uniform eigenstrians having perfect interface will be obtained. Secondly, the displacement and strain will be confirmed by the simulation of ANSYS in the inclusion, especially on the interface. Moreover, the solution will be compared with the Nozaki's thesis. Thirdly, employing the boundary element method, the original problem (having imperfect interface) will be solved on the basis of elastic fields with perfect interface. Finally, the Mori-Tanaka estimate is used to evaluate the effective moduli of polygon-shaped fibers composites having slightly weakened interface. The effective stiffness are compared with the ones by Nozaki for n=4. Numerical results show that the nature of the imperfectinterface has significant effect on stiffness of a convex polygon-shaped fibers composites.