Abstract: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.
[1] June J C, Thomas R H, Guo Y.System noise prediction uncertainty quantification for a hybrid wing-body transport concept[J].AIAA Journal, 2020, 58(3):1157-1170. [2] Casario K, Howard K, Smith M G, et al.The effects of nocturnal aircraft noise on self-reported sleep[J].Sleep, 2020, 43(Suppl 1):73-74. [3] Wu Y, Ai Y, Ze W, et al.A novel aerodynamic noise reduction method based on improving spanwise blade shape for electric propeller aircraft[J].International Journal of Aerospace Engineering, 2019, 2019(4):1-10. [4] Abbasi S, Souri M.Reducing aerodynamic noise in a rodairfoil using suction and blowing control method[J].International Journal of Applied Mechanics, 2020, 12(4):185-187. [5] Prasad C, Morris P.Effect of fluid injection on turbulence and noise reduction of a supersonic jet[J].Philosophical Transactions of the Royal Society A, 2019, 377(2159):235-239. [6] Pérez M A, Pernas-Sánchez J, Artero-Guerrero J A, et al.High-velocity ice impact damage quantification in composite laminates using a frequency domain-based correlation approach[J].Mechanical Systems and Signal Processing, 2021, 147:107-110. [7] Wei Q, Zhu L, Zhu J, et al.Characterization of impact fatigue damage in CFRP composites using nonlinear acoustic resonance method[J].Composite Structures, 2020, 253:112-120. [8] Demircan O, Al-darkazali A, İnanç İ, et al.Investigation of the effect of CNTs on the mechanical properties of LPET/glass fiber thermoplastic composites[J].Journal of Thermoplastic Composite Materials, 2020, 33(12):1652-1673. [9] Fang H, Gu J, Li Z, et al.An analytical model for temperature and crystalline evolution analysis of carbon fiber reinforced polymer composites during cooling[J].Polymer Composites, 2020, 41(10):4074-4083. [10] Sun K, Yi X, Sun B, et al.Study on microstructure and properties of TiBw/Ti-V-Al light weight high temperature shape memory composite[J].Journal of Alloys and Compounds, 2021, 851:156-159. [11] Konlan J, Mensah P, Ibekwe S, et al.Vitrimer based composite laminates with shape memory alloy Z-pins for repeated healing of impact induced delamination[J].Composites Part B:Engineering, 2020, 200:1083-1086. [12] Fu J, Hu Z, Song X, et al.Micro selective laser melting of NiTi shape memory alloy:Defects, microstructures and thermal/mechanical properties[J].Optics & Laser Technology, 2020, 131:1063-1070. [13] Pérez-Landazábal J I, Sánchez-Alarcos V, Recarte V, et al.Influence of structural defects on the properties of metamagnetic shape memory alloys[J].Metals, 2020, 10(9):1131-1136. [14] Mabe J, Cabell R, Butler G.Design and control of a morphing chevron for takeoff and cruise noise reduction[C]//11th AIAA/CEAS aeroacoustics conference.Monterey, California:AIAA, 2005:2889-2890. [15] Cortés-Puentes L, Zaidi M, Palermo D, et al.Cyclic loading testing of repaired SMA and steel reinforced concrete shear walls[J].Engineering Structures, 2018, 168:128-141. [16] Takeda T, Narita F.Fracture behavior and crack sensing capability of bonded carbon fiber composite joints with carbon nanotube-based polymer adhesive layer under Mode I loading[J].Composites Science and Technology, 2017, 146:26-33. [17] Liu B, Jin S, Chen K, et al.Study on cyclic deformation behavior of shape memory alloy materials considering damage and the residual strain[J].Journal of Alloys and Compounds, 2019, 797:1142-1150. [18] Travis S, Siddhant D, Aditi C.Fatigue damage behavior in carbon fiber polymer composites under biaxial loading[J].Composites Part B:Engineering, 2019, 174:106-110. [19] Hartl D J, Mooney J T, Lagoudas D C, et al.Use of a Ni60Ti shape memory alloy for active jet engine chevron application:II.Experimentally validated numerical analysis[J].Smart Materials and Structures, 2009, 19(1):15-21. [20] Liu B, Jin S, Dong S, et al.Studies on the fatigue damage behavior of active jet engine chevron[C].Proceedings of the 30th Symposium of the International Committee on Aeronautical Fatigue.Cham, Switzerland:Springer International Publishing, 2020:133-174. [21] Liu B, Jin S, Li X, et al.Study on behaviors of shape memory alloy materials under temperature cycling considering the damage[J].Journal of Intelligent Material Systems and Structures, 2020, 31(7):990-997. [22] Lagoudas D C, Bo Z, Qidwai M A.A unified thermodynamic constitutive model for SMA and finite element analysis of active metal matrix composites[J].Mechanics of composite materials and structures, 1996, 3(2):153-179. [23] 贺平, 刘金勇.碳纤维层合板有限元分析[J].数字海洋与水下攻防, 2018, 1(3):32-35.