Crack tip displacement factor-D: an application to two dimensional linear elastic fracture mechanics

Abstract

A fracture parameter, crack tip displacement factor D is introduced to characterize the two-dimensional linear elastic fracture mechanics problems. Similar to the conventional COD approach, the D factor can be determined directly from the crack surface displacement. The major advantage of using this fracture control parameter is that one can obtain it by evaluating the crack surface displacement from a numerical analysis or an experiment without the need for considering the stress field at the crack tip. Unlike the COD method, the introduced fracture parameter may be used for not only the simple opening mode but also for the sliding and tearing modes as well as for the mixed mode fracture problems. This article presents a detailed derivation of the D factor as well as some sample applications.