三点弯曲模式下C/SiC复合材料界面脱粘强度的数值模拟

Numerical Simulation of Interfacial Debonding Strength of C/SiC Composites in Three-point Bending Mode

利用ABAQUS软件对不同纤维方向下C/SiC复合材料界面在三点弯曲模式下的应力应变行为进行数值模拟,将引入内聚力模型模拟界面失效的仿真结果与实验结果进行分析对比。本研究模拟了PyC(热解碳)界面的脱粘过程,并得到了纤维方向和界面厚度对三点弯曲过程中界面脱粘强度的影响规律。结果表明,内聚力模型用于表征C/SiC复合材料的界面比较合理。纤维方向为横向和法向时的界面脱粘强度大致相等,约为26～28MPa。界面脱粘强度先随界面厚度增大而增大之后基本不变,界面厚度约为0.2～0.3μm时,界面脱粘强度达到最大。

Interfacial characteristics are crucial to the properties of the composites. In order to investigate the interfacial debonding strength of C/SiC composites, the stress-strain behavior of C/SiC composite interface under different fiber orientations in three-point bending mode was simulated by ABAQUS software. A cohesive zone model was applied to simulate the interface failure, and the simulation results were compared with the experimental results. The debonding process of the interface was simulated, and the influence of the fiber orientation and the interface thickness on the interfacial debonding strength during three-point bending test was obtained. The results show that the cohesive zone model is suitable to characterize the interface behavior of C/SiC composites. Interfacial debonding strength is approximately 26~28 MPa when the fiber orientation is transverse and normal. The interfacial debonding strength increases with the interface thickness until it remains stable. When the interface thickness is about 0.2~0.3μm, the interfacial debonding strength reaches the maximum value.