IMPACT CHARACTERIZATION OF GRAPHITE FIBER-REINFORCED THERMOPLASTIC LAMINATES

Instrumented drop-weight impact testings were conducted in conjunction with the ultrasonic C-scan and scanning electron microscopy to charac terize the impact response at low velocities. Thermoplastic composite materials in the simply supported case showed dramatic improvements in impact damage resistance compared to the thermoset composite material s as reported. Scanning electron microscopy examination of the fractur e surface revealed fiber-matrix-debonding, fiber pull-out, and few del eminations. Matrix behavior can be characterized by a hackly appearanc e. On the other hand, the fracture mechanisms of the transverse normal compression and shear punch were matrix cracking and grouped lamina d elamination as opposed to individual lamina delamination, respectively .