Unified Constitutive Modeling towards Enhanced Structural Integrity

Design and analysis of critical components in energy (nuclear, solar and fossil power), aerospace, automobile and chemical industries based on detailed inelastic analysis can enhance structural integrity and thereby economy. Especially for the components exposed to very high temperature thermomechanical fatigue loading, unified inelastic analysis based life prediction may enhance accuracy. A unified constitutive model (UCM) with features of strain rate-dependence, static recovery, mean-stress evolution, strain range-dependence, and finally creep damage is developed. The modified UCM is validated against simulating a broad set of strain-controlled isothermal and anisothermal fatigue and fatigue-creep responses, and stress-controlled creep responses of Haynes 230. Some of these results are presented to demonstrate improved simulations by the modified UCM. Importance of damage parameters in improving simulations in the tertiary creep regime is observed.