Calculation of stress intensity factor using weight function method for a patched crack with debonding region

Abstract

A patched crack with a debonded region is treated with a crack-bridging model: assuming continuous distribution of springs acting between crack surfaces. Adopting weight function method, the stress intensity factor for the patched crack within infinite plate is successfully obtained by numerical calculation. As the crack length a increases, the restraint on the relative displacement of the crack faces for a given value oo is increased. The constant relative displacement (or crack surface displacement) did explain the reason for the constant stress intensity factors being independent of the crack length. A simple asymptotic solution was proposed for estimating the reduction of patching efficiency due to debonding and compared with numerical solution obtained by weight function method. (C) 2000 Published by Elsevier Science Ltd.