Yu Jingwei, Zhang Peiwei, Chen Qiang, Fei Qingguo
School of Mechanical Engineering, Southeast University, Nanjing 211189, China.
Jiangsu Engineering Research Center of Aerospace Machinery, Southeast University, Nanjing 211189, China.
Materials (Basel). 2022 Jul 4;15(13):4679. doi: 10.3390/ma15134679.
This paper studies the yield behavior of a woven carbon-fiber-reinforced silicon-matrix (C/SiC) composite under dynamic tensile loading. Experiments were carried out to obtain the tensile properties of the C/SiC composite at a strain rate range of 2 × 10/s to 99.4/s. A strain-rate-dependent yield criterion based on the distortional strain energy density theory is established to describe the yield behavior. The interval uncertainty is considered for a more reliable yield prediction. Experimental results show that the yield stress, elastic modulus, and yield strain of the C/SiC composite grow with the increasing strain rate. The failure mode transitions from progressive crack extension to uneven fiber bundle breakage. The predicted results by the yield criterion match well with experimental data. Experimental results are enveloped within the uncertainty level of 45% in the critical distortional energy density, corresponding to an uncertainty of 14% and 11% in the yield stress and yield strain, respectively. With the support of the proposed strain-rate-dependent yield criterion, the yield behavior of the C/SiC composite under dynamic loading conditions can be predicted with reasonable accuracy.
本文研究了机织碳纤维增强硅基(C/SiC)复合材料在动态拉伸载荷下的屈服行为。开展实验以获取C/SiC复合材料在2×10/s至99.4/s应变率范围内的拉伸性能。基于畸变应变能密度理论建立了应变率相关的屈服准则来描述屈服行为。为了获得更可靠的屈服预测,考虑了区间不确定性。实验结果表明,C/SiC复合材料的屈服应力、弹性模量和屈服应变随应变率的增加而增大。失效模式从渐进式裂纹扩展转变为不均匀纤维束断裂。屈服准则的预测结果与实验数据吻合良好。实验结果被包含在临界畸变能密度45%的不确定性水平内,分别对应屈服应力和屈服应变14%和11%的不确定性。在所提出的应变率相关屈服准则的支持下,C/SiC复合材料在动态载荷条件下的屈服行为能够以合理的精度进行预测。