Damage mechanics based impact fatigue life prediction for an aircraft component

An important component in the landing system of an aircraft suffers cycled impact loadings in repeated landings, so it is necessary to analyze its impact fatigue strength. Continuum damage mechanics (CDM) method is new for impact fatigue problems. First, the component's detailed stress under static loadings and the fatigue dangerous point was determined, afterwards the stress response of the dangerous point under impulsive loadings were obtained. Second, the impact damage evolution equation and its material parameters identification were introduced. Taking the stress response as a loading spectrum, the damage mechanics finite element method was developed to predict the component's fatigue crack initiation life. With this method, the fatigue crack initiation life prediction for the component under impact loadings and non-impact loadings were carried on, and results were obtained. Finally, the equivalent relationship between lives under constant rate test load and constant rate impulsive load was obtained, which provides significant references for the component's equivalent fatigue experiment.