Dynamic fracture of C/SiC composites under high strain-rate loading: microstructures and mechanisms
Dynamic fracture of C/SiC composites under high strain-rate loading: microstructures and mechanisms
复制标题
高应变率载荷下 C/SiC 复合材料的动态断裂：微观结构和机制
DOI：
10.1016/j.carbon.2015.05.015
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发表时间：
2015-09-01
期刊：
影响因子：
10.9
通讯作者：
Luo, S. N.
中科院分区：
文献类型：
--
作者：
Li, T.;Fan, D.;Luo, S. N.
采用分离式霍普金森压杆（SHPB）和气枪加载，研究了C/SiC复合材料在高应变率压缩和拉伸条件下的动态断裂。所制造的复合材料的组件映射和量化与X射线计算机断层扫描，包括C纤维和纤维束，SiC基体，和束间和束内空隙。通过SHPB以10（2）-10（3）s（-1）的应变率沿着面外和面内方向施加压缩载荷，沿着进行原位X射线相衬成像。在应变率为10（4）~ 10（5）s（-1）的气炮冲击下，研究了离面方向的压缩和拉伸。对于面外加载，压缩通过空洞塌陷和剪切损伤带导致断裂，而对于面内方向压缩，分层断裂占主导地位。随着应变速率的增加，压缩破坏模式由束间断裂向束内断裂，再向纤维和束断裂转变。拉伸破坏包括分层、纤维拔出和纤维断裂。与正常固体相反，动态拉伸或层裂强度随着冲击速度的增加而减小，这是由于在随后的拉伸载荷之前压缩引起的预损伤。(C)2015爱思唯尔有限公司版权所有。
We investigate dynamic fracture of C/SiC composites under high strain-rate compression or tension with split Hopkinson pressure bar (SHPB) and gas gun loading. Components of the as-fabricated composites are mapped and quantified with X-ray computed tomography, including C fibers and fiber bundles, SiC matrix, and inter- and intrabundle voids. Compression loading is applied along the out-of- and in-plane directions by SHPB at strain rates of 10(2)-10(3) s(-1) along with in situ X-ray phase contrast imaging. Out-of-plane direction compression and tension are examined with gas gun impact at strain rates 10(4)-10(5) s(-1). For the out-of-plane loading, compression induces fracture via void collapse and shear damage banding, while delamination dominates fracture for the in-plane direction compression. With increasing strain rates, the compression failure modes transit from interbundle to intrabundle fracture of SiC, and then to fiber and bundle breaking. Tensile failure involves delamination, fiber pullout and fiber breaking. In contrary to normal solids, dynamic tensile or spall strength decreases with increasing impact velocities, owing to compression-induced predamage before subsequent tensile loading. (C) 2015 Elsevier Ltd. All rights reserved.