Analytical And Experimental Study Of Near Threshold Interactions Between Crack Closure Mechanisms

The results of an analytical closure model that considers contributions and interactions between plasticity-, roughness-, and oxide-induced crack closure mechanisms are presented and compared with experimental data. The analytical model is shown to provide a good description of the combined influences of crack roughness, oxide debris, and plasticity in the near-threshold regime. Furthermore, analytical results indicate that closure mechanisms interact in a non-linear manner such that the total amount of closure is not the sum of closure contributions for each mechanism. Newman, John A. and Riddell, William T. and Piascik, Robert S. Langley Research Center NASA/TM-2003-211755, NAS 1.15:211755, L-18207, ARL-TR-2774