Review A Review of Damage, Void Evolution, and Fatigue Life Prediction Models Hsiao Wei Lee and Cemal Basaran * Department of Civil, Structural and Environmental Engineering, University at Buffalo, New York, NY 14260-4300, USA;
[email protected] * Correspondence:
[email protected]; Tel.: +1-(716)-645-4375 Abstract: Degradation, damage evolution, and fatigue models in the literature for various engineer- ing materials, mostly metals and composites, are reviewed. For empirical models established under the framework of Newtonian mechanics, Gurson–Tvergaard–Needleman (GTN) type model, John- son-Cook (J-C) type damage model, microplasticity model, some other micro-mechanism based damage models, and models using irreversible entropy as a metric with an empirical evolution function are thoroughly discussed. For Physics-based models, the development and applications of unified mechanics theory is reviewed. Keywords: void evolution; degradation; damage; fatigue; fatigue-life; failure prediction; entropy; thermodynamics; unified mechanics; fracture; phase-field; GTN; J-C Citation: Lee, H.W.; Basaran, C. 1. Introduction A Review of Damage, Void Evolution and Fatigue Life The degradation, damage evolution, and fatigue behavior of materials are closely Prediction Models. Metals 2021, 11, related to structural performance and safety. It is well-understood that engineering mate- 609. https://doi.org/10.3390/ rials (such as metals and composites) have different micro-mechanisms, degradation pro- met11040609 cesses, damage accumulation, and different failure modes dependent on many factors. For example, when the strain rate is around 10−6 to 10−5 s−1, creep can be a dominant mech- Academic Editor: Jeremy S. anism; when around 10−4 to 10−3 s−1, it is defined as a quasi-static process; when above 103 Robinson s−1, it is usually regarded as a high strain rate, where inertia effects, thermal effects (e.g., adiabatic shear banding) and wave propagation influences must be taken into account [1].