Vibration fatigue experiment and finite element simulation of 2.5D woven composite cantilever beam

Abstract

2.5D woven composite has great application prospect in high bypass ratio commercial turbofan engine fan blades due to its comprehensive advantages in mechanical properties and complex component forming. For the aero-engine fan blades, vibration fatigue is a working condition that can not be ignored. At present, the research on vibration fatigue behavior of 2.5D woven composite is limited, and there is a lack of numerical model for vibration fatigue behavior simulation. In this paper, a multi-scale model for the first-order flexural vibration fatigue behavior of a 2.5D woven composite cantilever beam simulating the root of engine blade was established. Adopting the fatigue loading simulation method which adopted the fixed cycle jumping strategy, and the damage initiation criterion and fatigue stiffness degradation model based on the leading fatigue failure mechanism, the vibration fatigue test processes of the wrap and weft specimens were simulated respectively. With the established multi-scale model, the stress field in the unit cell of the dangerous part of the specimen was analyzed, and the damage state of the specimen after the vibration fatigue test was predicted. The numerical simulation results are consistent with the observed fracture morphology after the test, which verifies the validity of the proposed multi-scale prediction model for vibration fatigue of 2.5D woven composite materials. In addition, based on the multi-scale prediction model of vibration fatigue proposed in this paper, the damage states in the unit cell at the working section of the wrap specimen with the accumulation of fatigue loading cycles simulated, which is helpful to understand the evolutionary mechanism of vibration fatigue damage of 2.5D woven composite materials.

Keywords

• composites
• carbon fiber
• 2.5d woven
• multi-scale
• vibration fatigue