A Model for Predicting the Overload Effects on Fatigue Crack Growth Behavior AIAA-2003-1523

An analytical model using crack driving force13; parameter, K * was developed to account for the13; overload interaction effects on fatigue crack growth13; behavior. Crack growth acceleration and retardation13; were modeled using residual stress intensity concept.13; Fatigue crack growth behavior was predicted using this13; model for SE(T) specimen made from an aircraft grade13; D16 (2024-T3 equivalent) aluminum alloy, subjected to13; (a) constant amplitude load, (b) constant amplitude13; load, interspersed with single tensile overloads at13; certain intervals of crack length. Fatigue crack growth13; tests were performed under the above load sequences13; and the experimental crack growth results were13; compared with those obtained from the proposed13; model. All the fatigue tests were performed in a servo-hydraulic13; test machine and the crack length was13; measured by traveling microscope/ cellulose acetate13; replication method. A fairly good correlation was13; obtained between the experimental and predicted crack13; growth curves under the applied loading sequence.13