Improvement of Computational Efficiency by Hierarchization for Monte Carlo Simulation of Stress Corrosion Cracking
Hiromitsu SUZUKI, Ryosuke HARAKI, Keiichiro TOHGO and Yoshinobu SHIMAMURA
Abstract:A hierarchical model of a Monte Carlo simulation for the process of stress corrosion cracking (SCC) has been proposed to improve computational efficiency. A hierarchical simulation was developed based on the results of real size simulation which treats grain-sized micro cracks for initiation. In the real size simulation, initiation times, sites and length were assigned by random numbers based on an exponential distribution, a uniform distribution and a normal distribution, respectively, and stochastic data of initiation times, sites, lengths and aspect ratios for over 1mm cracks were obtained. In the hierarchical simulation which treats over 1mm cracks for initiation, initiation times, sites, lengths and aspect ratios were assigned by random numbers based on each distribution obtained by the real size simulation. The hierarchical simulation was carried out based on a real size simulation for a sensitized stainless steel type 304 under high-temperature and high-purity water environment. Simulation results for hierarchical and real size simulation have a good agreement with each other and computing time of analysis for large cracks can be significantly reduced by hierarchical simulation. Key Words:Stress corrosion cracking, Monte Carlo simulation, Crack initiation, Crack coalescence, Subcritical crack growth, Surface crack, Hierarchization