Damage Resistance of Three-Dimensionally Woven Carbon Fiber Composites
Publication Name: Engineers Australia
Publication URL: https://search.informit.org/doi/abs/10.3316/informit.862581842806778
This experimental work compares the damage resistance performance of a 3D woven composite to that of a conventional multi-directional laminate of comparable thickness, stiffness, and strength. Both materials were manufactured from Hexcel IM7 carbon fibers and Cycom PR520 toughened epoxy matrix using the resin transfer molding technique.
Damage resistance was evaluated using standard low-velocity drop-weight impact testing (AITM 1- 0010 with minor adaptations) under Barely Visible Impact Damage (BVID)-type conditions. Tests were performed with impact energies ranging from 20 to 130 J using a 16 mm hemispherical tup. Resulting damage was assessed using energy absorption analysis, damage area measurement with ultrasonic through-transmission C-scan imaging, failure mode analysis using micro-computed tomography (muCT), and simple dent depth measurements.
Comparisons were made between the responses of the two material systems by presenting the energy absorption, dent depth and C-scan damage-area metrics as functions of incident impact energy. This approach yielded a comprehensive understanding of the damage containment properties of the 3D woven composite. Additional insights into damage mechanisms were obtained using muCT scanning.
The 3D woven composite was found to absorb greater energy per unit damage area, lesser total energy for impacts over 50 J, and to suffer less damage by the metrics of C-scan area and dent depth.