对3种炭纤维增强树脂基复合材料(T300/NY9200Z、T300/QY8911和T700S/5228)层合板进行了落锤冲击实验,并对冲击后试样进行了冲击后压缩性能测试。通过对凹坑深度-单位厚度冲击能量(d-e)曲线,损伤面积-凹坑深度(S—d)曲线和冲击后压缩破坏应变-凹坑深度(ε-d)曲线的对比分析,讨论了这3种复合材料层合板的低速冲击性能(即损伤阻抗和损伤容限)。利用热揭层技术对拐点前后的复合材料损伤状态进行了观察,对损伤机制进行了讨论。实验结果表明,在3种材料的d—g曲线,S—d曲线和ε-d曲线上均存在对应的拐点,该拐点同时也是不同损伤形式的转变点。凹坑深度在小于拐点时,损伤形式以基体裂纹和分层损伤为主,凹坑深度大于拐点时,分层损伤基本不再扩展,损伤的发展主要以纤维断裂的扩展为主。
The drop-weight impact tests and compression after impact tests were conducted on three kinds of carbon fiber reinforced composite laminates (T300/NY9200Z, T300/QY8911 and T700S/5228). The low-velocity impact performances (damage resistance and damage tolerance) of these carbon fiber reinforced composites were analyzed through d-e curves, S- d curves, and ε-d curves. The detailed damage state around the transformation point was obtained by means of the thermal deply technique and the damage mechanism was discussed. The test results indicate that there are homologous knee points in these curves and these points are also the transformation points at which the damage mechanisms change significantly. The dominant damage is delamination and matrix cracking before the point, and it becomes fiber breakage after the point.