2D-C/SiC复合材料偏轴拉伸力学行为研究

Investigation on Off-axis Tensile Mechanical Behaviors of 2D-C/SiC Composites

通过对2D-C/SiC复合材料试件进行不同偏轴角度的拉伸实验,研究了偏轴角度对材料拉伸力学特性的影响。通过应变片分别测得了材料加载方向和纤维束方向上的应力-应变行为,对比分析了偏轴角度对上述应力-应变行为的影响;并结合试件断口扫描电镜照片,阐释了纤维束方向上拉伸和剪切损伤间的相互耦合效应。实验结果表明,材料的拉伸模量和强度随偏轴角度的增大出现明显下降;材料纤维束方向上的拉伸损伤和剪切损伤具有显著的相互促进作用。最后,以材料0°拉伸和45°拉伸实验数据为基础,建立了材料的偏轴拉伸应力-应变行为预测模型,模型预测结果与实验结果吻合较好。

The off-axis tensile mechanical behaviors of 2D-C/SiC composite laminates were obtained by tests under different off-axis angles, and the influence of off-axis angle on the tensile mechanical behaviors was studied.By sticking strain gauges on the surfaces of specimens, the stress-strain behaviors in the loading direction and in the fiber bundle directions of material were obtained and analyzed.Combined with the SEM （scanning electron microscope） results of fractured surfaces on specimens, the coupling effects between tensile and shear damage in the fiber bundle directions were also analyzed.Test results show that the tensile modulus and strength of material decrease significantly with increasing off-axis angle;and there exists obvious mutual effect between tensile and shear damage in fiber bundle orientation.Furthermore, based on the stress-strain data obtained from 0° and 45° tensile tests, a predictive model was built to predict the off-axis tensile stress-strain behaviors of material.The prediction has good agreement with test data.