Influence of Introduction and Distribution of Bonding Surfaces on Impact Resistance of Carbon Fiber Composite Laminates
摘要
Aiming to improve the impact resistance of structures, a technique to prepare carbon fiber composite laminates based on bonding methods was proposed. CFRP laminates with different numbers of bonding surfaces were fabricated, and then the impact toughness and impact bearing capacity of the laminates were evaluated based on pendulum and drop hammer impact tests, respectively. Results showed that the introduction of bonding surfaces noticeably reduced the generation of manufacturing defects within CFRP. Moreover, the bonding surface at 1/2 thickness as a neutral layer was conducive to the energy absorption of composite layers and the bonding surfaces at 1/4 and 3/4 thickness prevented the extension of shear cracks. As a result, compared to the specimen B0 without bonding surface internally, the specimen B1 with only one bonding surface at 1/2 thickness showed the best impact resistance in the drop hammer impact test. The peak force increased by 8.6% and the energy absorption before failure was increased by 30.6%. When three bonding surfaces were introduced and distributed at 1/4, 1/2 and 3/4 thickness, the best impact toughness was obtained in the pendulum impact test. The impact absorption work and impact toughness of the specimen B3 increased by 19.61% and 17.02%, respectively. However, the specimen B2 with two bonding surfaces distributed at 1/4 and 3/4 thickness showed poor impact bearing capacity. In conclusion, both B1 and B3 showed advantages in terms of impact resistance, proving the beneficial effects of the introduction of bonding surfaces with a reasonable distribution on CFRP.