K-Dominance zone for a semi-infinite mode I crack in a sandwich composite

A Mode I semi-infinite crack located at the midplane of an elastic layer sa ndwiched between two identical half-spaces is considered. The complete stre ss distribution for the eigenproblem with traction-free crack faces and loa ding at infinity is obtained. The auxiliary problem for a loaded crack is f irst solved using the Wiener-Hopf method and an eigensolution is derived by a limiting procedure. The solution is presented in closed form in terms of double quadratures. Based on an analysis of the stress field the size of t he K-dominance zone is determined and restrictions are established on emplo ying the conventional K-concept. (C) 2000 Elsevier Science Ltd. All rights reserved.