| Typical cracks in composite materials are hard to detect, because they may be very small or occur inside the material. This study investigates the development and characterization of carbon fiber and an ionomer, self-healing, laminate composite, enhanced with stitched artificial muscle elements. Although the carbon fiber is used as a structural reinforcement, the carbon fiber can also act as a resistive heating element in order to activate the healing elements in a Close-Then-Heal (CTH) approach. However in this study, hot air in an oven was used to activate the, SurlynRTM 8940, self-healing matrix. Artificial muscle was prepared from commercial fishing line to stitch reinforce the carbon laminate composite in the Z plane. Holes were drilled into the final composite and the muscle was stitched into the composite for active reinforcement. Differential scanning calorimetry was used to characterize the matrix and fishing line properties. The resulting smart composite was subjected to low velocity impact tests and consequential damage before healing in an oven, followed by three point bending flexure tests. Cracks in the carbon fiber reinforcement formed more easily than expected after impact because the holes were drilled to facilitate the muscle stitching. The matrix material could heal, but the reinforcement carbon could not. Several equipment issues and failures limited the amount of samples that could be created to continue testing with new parameters. |
