Fatigue life analysis of fluid-structure coupling characteristics for hollow wide-chord fan blade

The hollow wide-chord fan blade is one of the new techniques employed by the aero engine. Two fluid-structure interaction numerical methods including indirect coupling and direct coupling were implemented for the hollow wide-chord fan blade undertaking air flow field, and the fatigue life of the fan blade was analyzed. The fatigue life of the fan blade obtained by the two numerical methods was compared. Computational results show that the maximum stress is increased less than 10% with the direct coupling method compared with the indirect coupling one. The using coefficient of the fatigue life is almost zero under the von mises stress amplificatory level of 2 for hollow wide-chord fan blade using either of the two methods. Compared with the indirect numerical method, the coefficient of the fatigue life continuously increases with the increasing period under the von mises stress amplificatory level of 3.