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

Abstract

A center-cracked prate with a patch bonded on one side 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. When the crack length a is very small, the reduction in stress intensity factor was mainly due to the stress reduction from sigma (infinity) to sigma (0) which was calculated in the case of uncracked plate. As the crack length a increases, the restraint on the relative displacement of the crack faces for a given value sigma (0) became increased. The constant relative displacement (or crack surface displacement) did explain the reason for the constant stress intensity factors being independent to the crack length.