Experimental study on low-velocity impact performance of carbon fiber reinforced composite laminates

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 in-dicate 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 be-fore the point，and it becomes fiber breakage after the point .