Fracture Behavior of Notched Unidirectional Boron/Aluminum Metal Matrix Composite under Bending

The fracture behavior of continuous fiber reinforced boron/aluminum composite under bending is analyzed based on the measured full-field high resolution moire fringe patterns at the notch tip region of composites' specimen under three point bending. The mechanism of interfacial fiber/matrix sliding and debonding in bending is found to be quite different from those reported earlier for the case of uniform tension. In case of bending, after some initial crack growth, excessive shear deformation in other regions (other than notch tip) of the specimen makes the presence of notch irrelevant. Experimental results are compared with the results obtained from finite element analysis. J-integral values are evaluated using the displacements obtained experimentally and also by using finite element. It is realized that any numerical simulation should be based on elasto-plastic analysis and consider friction between fiber and matrix when excessive shear deformation occurs and sliding is initiated.