碳纤维叶片的鸟弹冲击响应及损伤

Bird impact response and damage of carbon fiber blades

通过实验和数值模拟研究了T300碳纤维叶片的抗冲击性能,探讨了碳纤维叶片的变形损伤模式及纤维层数对叶片抗冲击性能的影响。采用明胶鸟弹对不同层数碳纤维叶片开展了冲击实验,基于宏观连续损伤力学理论和Hashin失效准则针对碳纤维材料的失效形式编写了用户材料(vectorized user-material,VUMAT)子程序,采用光滑粒子流体动力学方法模拟明胶鸟弹,运用ABAQUS有限元软件对不同层数碳纤维叶片的动态响应过程进行了数值模拟,在鸟弹冲击过程中叶片变形、鸟流状态、冲击持续时间等方面,模拟结果与实验结果吻合较好。在鸟撞叶片初始冲击阶段,三种不同层数的叶片都有较大的变形,且叶片的变形模式相近;在冲击衰减阶段与恒流稳定阶段,不同层数碳纤维叶片的挠度与断裂位置都有较大差别。在鸟弹冲击叶片过程中,叶片以弯曲和扭转耦合变形模式为主,其中弯曲变形对其损伤破坏起主导作用。实验结果表明,碳纤维叶片损伤模式主要表现为:(1)叶根部边缘损伤,(2)叶根部完全断裂,(3)叶根部与叶顶部完全断裂。碳纤维抗冲击性能受层数的影响较大,通过实验和数值模拟对鸟弹冲击叶片进行机理分析,可为碳纤维叶片的工程设计和应用提供参考。

The impact resistance of T300 carbon fiber blades was studied through experiments and numerical simulations.The deformation damage pattern and the effect of the number of fiber layers on the impact resistance of the blade are studied.The impact experiment was conducted on the carbon fiber blades of different layers.Based on the macro-level continuum damage mechanics theory and the Hashin failure criterion,a vectorized user-material subroutine was written for the carbon fiber material,and the smooth particle hydrodynamics algorithm was used to simulate the gelatin projectiles.Numerical simulations of bird impact on the composite blades with different layers were carried out in ABAQUS/Explicit.The blade deformation process,bird flow state,and impact duration time of the experiments agree well with the numerical results.In the initial impact stage,the blade specimens have large deformations,and the deformation modes of the three carbon fiber blades with different layers are similar to each other.However,in the impact attenuation and constant flow stages,the deflection and fracture of different layers of carbon fiber blades are quite different.The damage mode of the 6-layer carbon fiber blade is complete fractures at the blade root and top,the damage mode of the 8-layer carbon fiber blade is root fracture,and there is no obvious macroscopic visible damage in the 10-layer carbon fiber blade.Under the gelatin projectile impact loading,the blade deformation mode is mainly coupled with the bending and torsional deformation process,and the bending deformation dominates the damage and failure process.Experimental results show that the damage pattern of carbon fiber blades is mainly classified as(1)edge damage at the root,(2)complete fracture at the root,and(3)complete fracture at the root and top edge.The impact resistance of carbon fiber is greatly influenced by the number of layers.The mechanism analysis of gelatin projectile impact on carbon fiber blades through experiments and numerical simulations can provide a reference for the engineering design and application of carbon fiber blades.