碳纤维复合材料冲击模型率相关修正方法与试验研究

Rate-Dependent Correction Method and Experiment Study of the Impact Model of Carbon Fiber Reinforced Composites

目前先进航空发动机的风扇叶片均采用复合材料结构,为了研究其在工作过程中可能受到的冲击损伤,即碳纤维增强树脂基复合材料受到高速冲击后的损伤与破坏过程,对其准静态下的正交各向异性本构模型和失效准则进行修正,建立了应变率相关的三维动态本构及损伤模型.该模型考虑了材料模量、强度和断裂韧性与应变率的相关性,并采用基于断裂韧性的渐进损伤模式对刚度进行折减来控制破坏过程.开展了不同应变率下的动态试验,得到基体方向拉伸与剪切的动态响应数据,拟合得到相应的动态修正因子.将该模型结合修正因子植入数值软件进行仿真计算,分析结果表明,所建立的率相关本构及损伤模型能够更准确地模拟层合板受冲击过程的损伤和破坏,与试验吻合较好.

Composite structures are widely used in the fan blade of the advanced aero engines.To study engine fan blade impacted in the working process.To study the possible impact damage of the engine fan blades during the working process,that is,the damage and failure process of carbon fiber reinforced resin matrix composites(CFRRMC) subjected to the high-speed impact,the orthotropic constitutive model and the failure criterion of CFRRMC under the quasi-static condition were modified,and a 3D dynamic constitutive model with strain rate-dependency was established in this study.In this model,the relationships between the modulus,the strength and the fracture toughness of the material and the strain rate were considered,and the progressive damage mode based on fracture toughness was adopted to reduce the stiffness and thus control the failure process.In this study,dynamic tests under different strain rates were carried out to obtain the dynamic tensile and shear responses along the matrix direction,and the corresponding dynamic correction factors were obtained by fitting.The simulation results show that the proposed ratedependent model can more accurately simulate the damage and failure of the laminates under the impact loads,and is more consistent with the experimental results.