Characterization and Simulation of Time-Dependent Response of Structural Materials for Aero Structures and Turbine Engines

Abstract

When considering structural materials used in aerospace applications and time-dependent behavior, primary concern are material/microstructural changes and damage initiation and growth as a result of complex loading (creep and/or fatigue) scenarios and/or environmental attack. The degradation and damage in the material can result in a decrease in load-carrying capability. It is the decrease of capability as a function of time/usage/exposure that must be understood and predicted to optimize the design and life management strategies of aerospace components that comprise aircraft structures and turbine engines. Historically predictive models in these domains were empirically based; relying on accelerated test methods, extensive amounts of test data, and mathematical fits to that data. More recent research in time-dependent material properties has shifted the focus to understanding the underlying mechanisms of material degradation and developing predictive capabilities incorporating that understanding. Specifically, to realize more accurate and robust performance prognosis for structural materials, a shift from empirical descriptions of time-dependent material behavior to more mechanistic-based models that capture the physics of failure is needed.