Damage develops fast after that period . and a nonlinear formula with parameter of unloading modulus and residual strain was brought out to describe damage development in tensile test . it is also found that mechanical properties of c fiber are much less than those of t300 fiber bundles 另外,通过进一步的分析发现三维编织c sic复合材料中纤维束的就位性能远远低于其摘要原位性能,这正是c / sic复合材料的拉伸性能远低于t300 / qy9512复合材料的主要原因。