基于有限元模拟的碳纤维复合材料层合板拉伸失效机理分析

Analysis of Tension Failure Mechanism of Carbon Fiber Composite Laminates Based on FEM Simulation

碳纤维增强树脂复合材料(CFRP)具有高比强度、良好的耐腐蚀性,在汽车轻量化研究中受到很大重视。设计了三种不同铺层方式的碳纤维增强环氧树脂复合材料层合板(单向铺层([0°]_(8)),各向同性铺层([0_(2)/45_(2)/90_(2)/-45_(2)]_(s)),有取向铺层([0/45_(2)/90/-45_(2)/0_(2)]_(s))),研究其拉伸破坏形式,并结合有限元模拟进行分析验证。结果表明,拉伸强度与模量主要取决于层合板中沿拉伸方向排列的纤维层数量占比,占比越高,拉伸强度与模量越大。不同角度铺层呈现不同破坏形式,断裂时0°层纤维与基体均发生破坏;±45°层与90°层断裂主要以基体开裂为主;层间结合较好的情况下,0°层和90°层会受到相邻±45°层的影响发生剪切破坏。有限元模拟结果与试验结果匹配度较高,为后续建立汽车零件级产品失效模式评估系统奠定了基础。

Carbon fiber-reinforced resin Plastic(CFRP)has been paid more attention in the field of automotive lightweight research because of its high specific strength and good corrosion resistance.Three types of laminates with different ply sequences including unidirectional layer([0°]_8),isotropic lay([0_2/45_2/90_2/-45_2]_s)and anisotropic lay([0/45_2/90/-45_2/0_2]_s)were designed to study the tension failure modes and verified by FEM simulation.The results showed that the tension strength and modulus mainly depended on the proportion of the number of fiber layers in the tensile direction.The higher the proportion,the greater the tensile strength and modulus.Layers with different angles had different failure modes.Both the fiber and the matrix of 0°layers were damaged while the fracture of±45°or 90°layers mainly focused on the crack of the matrix after tension.With good combination of layers,0°layer and 90°layer were influenced by the adjacent±45°layers and had shear failure.The high matching degree of FEM simulation results and test results laid a foundation for the subsequent establishment of failure mode evaluation system of automobile parts.