Damage Behavior of 2D C/SiC Composites under Low Velocity Impact

Low velocity impact (LVI) damage behavior of 2D C/SiC composite was experimentally investigated. C/SiC laminates were impacted under various energy levels ranging from 1.5J to 9J by a dropping hammer. Impact damages were characterized by surface measurement and two nondestructive test (NDT) methods, which were ultrasonic C-scan and infrared thermal wave. The effect of impact energy on post-impact compressive performance was studied by static compress test. The results indicate that C/SiC behaves in a damage tolerant manner. While damage is produced under very low energy, but it is bounded in a limited area and no catastrophic failure occurs under all energy levels. LVI damage area increases with the impact energy. After impact of 1.5J, nearly no visible damage is found. When the impact energy increases to 9J, the specimen is nearly penetrated. LVI is a great threaten to the loading capacity of C/SiC, since the nominal compressive strength and modulus decreases maximum to 44.7% and 16.9%, respectively.