Fracture behaviour and toughness of a plane-woven SiC fibre-reinforced SiC matrix composite
Fracture behaviour and toughness of a plane-woven SiC fibre-reinforced SiC matrix composite
复制标题
DOI：
10.1016/0921-5093(96)10170-2
复制
发表时间：
1996-06
期刊：
影响因子：
6.4
通讯作者：
K. Goto;Y. Kagawa
中科院分区：
文献类型：
--
作者：
K. Goto;Y. Kagawa
研究了化学气相渗透法制备的双向编织SiC纤维增强SiC基复合材料的断裂行为和断裂抗力。拉伸应力-应变曲线在70 MPa以上显示出非线性行为，并且有效杨氏模量在该拉伸应力以上降低。复合材料的有效杨氏模量在断裂时约为初始值的40%，并且所有施加的断裂载荷由纵向纤维束复合材料（FBCs）支撑。缺口试样的总断裂应力显示出降低缺口敏感性与单片SiC基体相比，虽然它从来没有完全消失。复合材料的断裂韧性增加的起源解释使用FBC桥接模型，采用从单独的拉伸试验获得的FBC的强度。结果表明，在纵向FBC断裂之前发生的横向FBC开裂对桥接状态起着重要的影响，所提出的FBC桥接模型可以模拟复合材料的拉伸断裂强度和韧性。
This study investigates the fracture behaviour and fracture resistance of a bi-directional woven SiC fibre-reinforced SiC matrix composite fabricated by chemical vapour infiltration. The tensile stress-strain curve shows nonlinear behaviour above 70 MPa, and the effective Young's modulus decreases above this tensile stress. The composite's effective Young's modulus at fracture was about 40% of the initial value, and all the applied load at fracture was supported by the longitudinal fibre bundle composites (FBCs). The gross fracture stress of a notched specimen showed reduced notch sensitivity in comparison with a monolithic SiC matrix, though it never completely vanished. The origin of the increase in the composite's fracture toughness was explained using an FBC bridging model that employs the strength of an FBC obtained from separated tensile testing. Results demonstrate that the cracking of the transverse FBC, which occurs before longitudinal FBC fracture, plays an important role affecting the bridging condition, and that the tensile fracture strength and toughness of the composite can be modelled by the presented FBC bridging model.