含孔和切口C/C编织复合材料静态拉伸下的力学性能

通过对中心开孔、 双边半圆切口和双边V型切口三种结构的静态拉伸测试及有限元模拟分析, 比较了不同开孔/切口形式C/C编织复合材料的破坏行为。结果表明: 三种开孔/切口形式的C/C试件在拉伸破坏中均表现为较强线性的应力-应变关系, 且开孔/切口附近有明显的应力集中; 板宽不变时, 缺口强度对开孔/切口尺寸不敏感, 而对其端部的曲率半径较敏感; 孔端部材料不满足线弹性的破坏机制, 发生了大规模的应力松弛, 其尺寸随开孔/切口曲率半径的增大而增大, 而对开孔/切口位置不敏感。

Mechanical properties analysis of 3D C/C braided composite opening structures under static tension

The tensile fracture of the 3D C/C braided composite structures was studied through the static tensile test and finite element simulation analysis. Three modeling structures including circularly holed, double-edge-semicircle and double- edge-V-shaped specimens were considered for the investigation. The results show that the three open structures in the tensile failure have a strong linear stress-strain relationship and locality stress concentration. At the fixing width of the C/C specimens, the tensile notched strength is not sensitive to size, but it is sensitive to the radius of the notch-tips. The linear elastic failure mechanism can not be applied to the damaged zone of the material, which suggest that a large-scale stress relaxation should exist. The size of the damaged zone increases when the radius of the notch-tips increases, while the size is insensitive to the location of the openings.