ABSTRACT
The influence of the contact and friction interaction taking place between the debonded surfaces on the arrest of further debonding extension in Graphite/Aluminum single-fiber composite materials was studied. In this specimen, a broken Graphite fiber, perpendicular to the fiber axis and a small debonding was considered. The composite is modeled as a two-material cylinder subjected to uniform displacement and consisting of an inner cylinder simulating the fiber and a surrounding shell simulating the metallic matrix. The specimen is subjected to a monotonic increasing uniform displacement perpendicular to the plane of the originally cracked fiber. An elastic-plastic finite element analysis was performed based on the finite element code ABAQUS to study the fracture behavior. A very detailed analysis of the stress field in the vicinity of the crack tip was undertaken. The results of stress analysis were coupled with the strain energy density theory to predict the crack growth behavior including crack initiation, crack growth extension/direction and final termination along the constituents interface. The influence of contact and friction interaction taking place between the debonded surfaces is also considered into the numerical study. It is obtained that the presence of such surfaces being in contact can lead to considerable reduction of the calculated stress fields near the crack front. It is shown that the followed analysis combined with the strain energy density criterion can explain the arrest of further debonding extension observed during experimental testing. The total debonding extension length under the critical applied displacement for fully fractured fiber was calculated.
