平纹编织C/SiC复合材料层合板偏轴拉伸性能研究

STUDY OF OFF-AXIS TENSILE PROPERTIES OF PLAIN-WOVEN C/SiC COMPOSITES

通过理论和试验方法,分析了平纹编织C/Si C复合材料的偏轴拉伸性能。在室温下进行(0°/90°)和(±45°)、(30°/60°)试件的轴向拉伸试验和(0°/90°)试件的面内剪切试验。结果表明,材料的面内力学性能与材料纤维的方向角有明显的关系。经典层合板理论在初始低应力阶段仍然适用于平纹编织C/Si C复合材料,但随着载荷的增大,由于拉剪损伤耦合效应的影响,计算的应力-应变曲线逐渐偏离试验曲线。根据试验数据,给出了拉剪耦合的影响公式,对经典层合板理论模型进行修正,由修正后模型得到的计算应力-应变曲线与实测曲线吻合很好。

The off-axis tensile properties of plain woven C/SiC composites were studied through theoretic and experimental approaches. The axial tensile tests of （0°/90°） , （ ± 45°） and （30°/60°） specimens as well as the in-plane shear test of （0°/ 90°） specimen were carried out at room temperature. The results show a remarkable correlation between in-plane mechanical properties and fiber orientation. The classical laminate theory is still appropriate for C/SiC composites at initial low-stress period, but the calculated stress-strain curve is deviated from the experimental curve because of the influence of coupling of tensile and shear damage during the stress increasing. The influence of coupling of tensile and shear damage was given according to experimental data, then it was used to modifying the classical laminate theory, and the calculated stress-strain curve obtained by the modified model is in good agreement with the experimental curve.