二维三轴编织复合材料压缩失效行为的细观有限元模拟

A meso-scale finite element model is developed to predict the progressive damage behavior of the two-Dimensional Triaxially Braided Composite (2DTBC) subjected to compressive loading conditions. A unit cell model that reflects the realistic geometrical properties of the braided composite is established. Based on Murakami-Ohno damage theory, an anisotropic damage model is established to simulate the damage initiation and the propagation process in fiber bundles. Undulation coefficient is introduced to describe the extent of undulation. The interfaces are simulated using the cohesive element model. The compressive damage process of 2DTBC is systematically illustrated and analyzed using the meso-scale finite element model, with special focus on the damage evolution process of fiber bundles and interfaces, and the effect of fiber bundle undulation on the effective compressive properties. The proposed model shows excellent correlation with the experimental results, not only capturing the global stress-strain responses, but also capturing the progressive damage behavior and the free-edge effect of the composite. The results indicate that the axial compression failure of the 2DTBC is dominated by the fiber-compression failure of axial fiber bundles, and the transverse compression failure is caused by the fiber-compression failure of bias fiber bundles.