Finite Element Analysis on the Impact-induced Damage of Composite Fan Blades Subjected to a Bird Strike

Carbon fiber-reinforced composites have been recently applied for engine fan blades because of their high specific strength. In the design of the fan blade, bird-strike impact is one of the greatest concerns, since impact-induced damage can lead to the engine stalling. This study presents a numerical method to analyze bird-strike impact as a soft-body impact on a cantilevered composite panel. Especially, we coupled a stabilized dynamic contact analysis, which enables appropriate prediction of impact force on the panel, with laminate damage analysis to predict the impact-induced progressive damage in the composite. This method is verified through a comparison with experimental results. With the numerical method, we investigate the effect of impact condition, blade thickness and shape on the impact-induced damage in a composite fan blade subjected to a bird strike. An intermediate blade thickness and a large blade curvature help to improve the bird-striking impact resistance of the composite.