摘要
设计了双向拉伸十字型试样,采用不同的加载比例和加载方向对三维轴编C/C复合材料进行双向拉伸实验,面内方向施加1∶1和1∶2的载荷,面外方向施加1∶1的载荷。实验结果表明,十字型试样的初始破坏发生在中心打薄区域,材料为脆性断裂。面内双向拉伸破坏主要为径向纤维束的断裂和基体的开裂,断口大多沿60°方向;面外双向拉伸破坏主要以纤维束的断裂、炭棒的拔出和基体开裂为主,断口形貌较为复杂。材料在不同载荷形式下有着不同的强度值,相对于单向拉伸强度,存在强度弱化现象。根据实验数据确定了蔡-吴强度准则的参数,为三维轴编C/C复合材料结构强度设计及校核提供参考。
Biaxial tensile experiments of 3D in-plane braided C/C composites were carried out by cruciform specimen under different loading ratios and loading directions.The loading ratios were 1 ∶ 1 and 1 ∶ 2 in X-Y plane and 1 ∶ 1 in X-Z plane. The re-sults show that all of the specimens fail in the gage section and represent brittle fracture.The failure modes of specimen in X-Y plane are matrix cracking and fiber bundle breakage.The direction of fracture plane is 60° with respect to one loading direction. The failure modes of specimen in X-Z plane are dominated by the fiber rod pulling breakage.The C/C composites strengths under biaxial loading become lower than that under uniaxial results.The parameters of Tsai-WU criterion are determined by experimental data,which may be helpful to the strength design and evaluation of the 3D in-plane braided C/C composites structures.
出处
《固体火箭技术》
EI
CAS
CSCD
北大核心
2015年第2期267-272,共6页
Journal of Solid Rocket Technology
基金
国家自然科学基金(11325210
11102051)
关键词
C/C复合材料
三维轴编
双向拉伸
强度
破坏机制
C/C composites
3D in-plane braided
biaxial tensile
strength
failure mechanism
