CRACK PROFILES IN APPLIED MOMENT DOUBLE CANTILEVER BEAM TESTS

In situ observations of crack propagation in an applied moment double cantilever beam specimen were used previously to obtain the R-curve be havior of ceramic composites. To predict the R-curve using constitutiv e models, knowledge of the crack profile is required to derive the bri dging stress distribution along the crack length and to analyze the to ughening effect. To predict the crack profile in an applied moment dou ble cantilever beam test, both the deformation of the crack surface du e to the bending moment and the movement of the crack surface due to t he rigid body motion of the loading fixture need to be considered. The analytical solution for the crack profile is derived in the present s tudy. The predicted crack profiles agree well with experimental measur ements.