PREDICTION OF FAILURE IN NOTCHED INFINITE STRIPS BY THE COHESIVE CRACK MODEL

The potential energy principle of the cohesive crack model is discussed under the condition that the loading device has finite compliance. The relation between crack instability and the second-order variance of the potential energy is examined. With linear softening law, a simple peak load solution is derived from the singularity condition of the potential energy. The obtained formulation is then applied to infinite strips with either central cracks or edge cracks loaded by remote uniform tension. The convergence of the cohesive crack model to linear elastic fracture mechanics solution is demonstrated. It is emphasized that although the concept of failure by crack instability is not ubiquitous, it can provide a common ground to unify linear and nonlinear fracture mechanics as well as tensile strength theory.