Permanent indentation and damage creation of laminates with different composite systems: An experimental investigation

Quasi-static indentation (QSI) and low-velocity impact tests have been conducted to laminated composite specimens made from different composite systems. C-scan and thermal deply techniques were used to observe the internal damage characteristics of the laminates. The test results show the effect of fibers and matrices on the permanent indentation and damage behaviors of composite laminates. Fiber breakage plays an important role in the formation of permanent indentation and the match between the fiber and matrix also has a significant influence on the permanent indentation and damage behaviors. A comparison shows the correlation between the peak load energy of the QSI tests and the knee point energy of the impact tests, based on which a condition for the prominent indentation formation was proposed for the impact tests.