The variable geometry chevron(VGC) is a sawtooth aerodynamic device composed of an annularly distributed single chevron at the tail of the engine, and is used to reduce the engine noise. The VGC is deformed repeatedly during takeoff and landing of the aircraft, which would cause the structural fatigue of the VGC. Based on the existing constitutive model of the Shape Memory Alloy(SMA) and the fatigue test of the Carbon Fiber Reinforced Plastics(CFRP), a damage factor is introduced in a finite element subroutine to analyze the mechanical properties of the VGC when the SMA and the CFRP are damaged in a certain degree. It is shown that the damage of the VGC is mainly caused by the SMA. As the number of the deformation cycles increases, the maximum Mises stress in the VGC gradually decreases and the maximum displacement gradually increases. Compared with the simulation of a single chevron, the maximum Mises stress of the VGC with the same damage degree is larger, and the maximum displacement of the VGC is smaller than the tip deflection of the single chevron. The research results can provide a guidance for the safe operation of the VGC.

variable geometry chevron  /  shape memory alloy  /  structural damage  /  finite element simulation