含缺陷C/C-SiC缎纹编织复合材料的压缩损伤及失效机制

Compression damage and failure mechanism of C/C-SiC satin woven composites with void defects

为了研究含孔隙缺陷缎纹编织复合材料的压缩力学性能和失效机制,开展了含孔隙C/C-SiC缎纹编织复合材料的经向压缩实验;通过基于离散单元法的爆炸碎片算法来引入随机孔隙,建立了含孔隙缺陷缎纹编织复合材料的细观强度预测模型。基于该模型模拟了经向压缩载荷下细观模型的渐进失效过程,揭示了孔隙对损伤过程的影响规律,结合实验数据对渐进损伤过程和失效机制预测模型进行了验证。结果表明,在经向压缩载荷下材料主要破坏模式为剪切破坏和分层破坏,具体表现为三种形式:层间局部基体开裂、基体与经纱脱粘后分层,经纱整束断裂、部分断裂,以及纬纱脱粘与基体分离、纬纱开裂。同时数值模拟结果与实验值基本相同,验证了该含孔隙缺陷C/C-SiC缎纹编织复合材料模型的有效性,为二维编织复合材料的力学性能研究提供了一种有效方法。

To study the compressive mechanical properties and failure mechanism of satin woven composites with void defects,the longitudinal compression experiments on C/C-SiC satin woven composites with void defects were conducted.The microscopic strength prediction model of satin woven composites with void defects was established by introducing random pores through the explosive fragment algorithm based on the discrete element method.Based on this model,the progressive failure process of the mesoscopic model under meridional compression load was simulated,revealing the influence of pores on the damage process.The progressive damage process and failure mechanism prediction model are verified by experimental data.The results show that the main failure modes of the material under warp compression load are shear failure and delamination failure,manifesting in three forms:interlaminar local matrix cracking and associated,delamination between the matrix and the warp,complete or partial fracture along the warp and weft debonding and matrix separation,weft cracking.At the same time,the numerical simulation results are basically the same as the experimental values,which verifies the validity of the model of C/C-SiC satin woven composites with void defects,and provides an effective method for the study of mechanical properties of two-dimensional woven composites.