Modification of weight function method to predict stress intensity factors of two cracks

Abstract

The stress intensity factor K is a very important parameter in fracture mechanics. For example, it is needed to calculate critical crack length and remaining strength or life for structural components which contain cracks. Many numerical and analytical methods of obtaining K solutions have been developed since 1950s. It is known that a powerful feature of a weight function approach is the ability to determine K solutions for an arbitrary applied stress. Weight function methods have been applied extensively to problems concerning a single crack. So far, no attempt has been made to use a weight function method to determine K solution for two cracks. This paper discusses the development of a novel weight function method in order to predict K values of two edge cracks in a finite body under uniform tension. The crack interaction effect was established using a non-uniform stress distribution along the potential crack plane to simulate the presence of an additional edge crack. The FE modelling technique used in this paper is also briefly discussed. Overall results obtained from the weight function approach are encouraging as they display the general expected trend and compare well to the FEA results.