Li Longbiao
College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, No.29 Yudao St., Nanjing 210016, China.
Materials (Basel). 2020 May 28;13(11):2469. doi: 10.3390/ma13112469.
In this paper, the effect of stochastic loading on tensile damage and fracture of fiber-reinforced ceramic-matrix composites (CMCs) is investigated. A micromechanical constitutive model is developed considering multiple damage mechanisms under tensile loading. The relationship between stochastic stress, tangent modulus, interface debonding and fiber broken is established. The effects of the fiber volume, interface shear stress, interface debonding energy, saturation matrix crack spacing and fiber strength on tensile stress-strain curve, tangent modulus, interface debonding fraction and fiber broken fraction are analyzed. The experimental tensile damage and fracture of unidirectional and 2D SiC/SiC composites subjected to different stochastic loading stress are predicted. When fiber volume increases, the initial composite strain decreases, the initial tangent modulus increases, the transition stress for interface debonding decreases and the initial fiber broken fraction decreases. When fiber strength increases, the initial composite strain and fiber broken fraction decrease.
本文研究了随机载荷对纤维增强陶瓷基复合材料（CMC）拉伸损伤和断裂的影响。建立了一个考虑拉伸载荷下多种损伤机制的细观力学本构模型。建立了随机应力、切线模量、界面脱粘和纤维断裂之间的关系。分析了纤维体积、界面剪应力、界面脱粘能、饱和基体裂纹间距和纤维强度对拉伸应力-应变曲线、切线模量、界面脱粘分数和纤维断裂分数的影响。预测了单向和二维SiC/SiC复合材料在不同随机加载应力下的拉伸损伤和断裂情况。当纤维体积增加时，复合材料的初始应变减小，初始切线模量增加，界面脱粘的转变应力减小，初始纤维断裂分数减小。当纤维强度增加时，复合材料的初始应变和纤维断裂分数减小。
