Brittle Fracture Failure Analysis under Mixed-Mode Condition Using Asymmetric Edge Cracked Semicircular (AECS) Configuration

Abstract

The non-destructive assessment of structural elements enables the high-resolution identification of fractures and other failures. Fracture mechanics offers concepts for lifetime prediction of components when component geometry, material properties, and load intensity under steady state or impact loading are known. This is true when cracks are involved in mechanical failure events. Mixed-mode brittle fracture is one of the frequent forms of mechanical failure in components made up of quasi-brittle or brittle materials. Investigating the structural integrity of damaged components under mixed-mode loads is crucial.

For studying mixed mode fracture in brittle materials, an Asymmetric Edge Cracked Semi-circular (AECS) specimen exposed to asymmetric three-point bend load was recommended. The crack parameters were derived using finite element analysis for various crack lengths and varied loading point locations. It was demonstrated that entire mode mixities from pure mode I to pure mode II could be accomplished by choosing the proper places for the loading points. The proposed specimen was then used to perform a number of fracture tests on epoxy resin material. The experimental findings and those predicted by the maximum tangential stress criteria showed a very high degree of agreement.