The problems of a concentric penny-shaped crack at the interface between two transversely isotropic media in an infinite cylinder

Abstract

This paper is a continuation of the problem of interface cracks in previous works by the author (Zhang, Engng Fracture Mech. 24, 177, 1986; 28, 379, 1987). In this paper, it is proven once again that the stress intensity factor of a penny-shaped crack at the interface between two different layers in a transversely isotropic solid is independent of material constants, and that both K I and K I cannot appear at the same time if the interface crack is subjected to normal or shear stress alone. Of course the conclusion in this study is also contrary to those in Sih ( Mechanics of Fracture—6, Cracks in composite materials, p. 129, 1981), Arin and Erdogan ( Int. J. Engng Sci., 9, 213, 1971), Sneddon ( Application of Integral Transform in the Theory of Elasticity, p. 59, 1975) and Kassir and Bregman ( J. appl. Mech, 39, 308, 1972). However, it is believed that the new conclusion given previously and in this article shall be used instead of the old conclusion in other works for the problem of interface crack, because † † In addition, the solutions in some other works given are only special cases of the results in another work by the author and this paper, respectively. the new one has been sufficiently proven by use of the simple and easy method given.