Richard P. Gangloff

A propagation approach to manage stress corrosion cracking is justified for modern high strength alloys that exhibit low-subcritical crack growth rates, and is enabled by maturing probabilistic fracture mechanics and mechanism-based hydrogen damage modeling. A code, SCCrack, is developed based on stress intensity (K) similitude and fast Monte Carlo analysis to predict SCC life distributions from input distributions of variable material crack growth rate (da/dt vs K), starting crack size, environment, and stress. Growth rates are obtained using an accelerated experiment that exploits precision electrical potential measurement of crack propagation, small crack size, and slow-rising K loading. Data are leveraged by fundamental models of SCC threshold (K_TH) and H-diffusion limited Stage II da/dt, built on the hydrogen environment assisted cracking mechanism. With these inputs, SCCrack enables multi-scale “What if?” simulations of the effects of alloy-environment-precorrosion variables ...