Combined Creep and Fatigue Modeling

Simultaneous consideration of creep and fatigue is of paramount importance to accurately predict component life in many industrial applications. For example, growing penetration of renewable energy onto the grid is forcing many power plants to transition from base-load power generation to more complex operation modes, characterized by a combination of base-load generation and frequent start-up and shut-down cycles. The frequent start-stop of power plants is causing a significant toll in the component life due to fatigue. As such, creep alone is not adequate anymore to predict the component life. Most existing life prediction models consider creep or fatigue independently while neglect their interactions. In this presentation, we talk about some recent efforts at NETL to develop a unified modeling framework where both creep and fatigue can be considered. The creep-fatigue interaction mechanism is studied. High-throughput simulations are performed under various hold stress and hold time, and analytical expressions are fitted for the crack growth rates under creep and/or fatigue conditions demonstrating some applications of this newly developed modeling capability. . Authors: Xue, Fei [NETL Site Support Contractor, National Energy Technology Laboratory]; Cheng, Tianle [NETL Site Support Contractor, National Energy Technology Laboratory]; Lei, Yinkai [NETL Site Support Contractor, National Energy Technology Laboratory]; Wen, Youhai [NETL] (ORCID:0000000241632616). Subjects: advanced alloy development; computational materials