Improving impact resistance of carbon-fibre composites through interlaminar reinforcement

Inclusion of a thermoplastic phase to improve impact and post-impact performances of carbon fibre reinforced thermosetting composites — A review

“…The undamaged compressive strength of specimens toughened with PP veils was reduced slightly whilst the HDPE veils increased the strength. Similar to previous publications [99,114], it was found that the damage areas were reduced for laminates toughened with veils. The residual compressive strengths of the damaged specimens were increased by 18% and 32% for PP and HDPE, respectively, as the propagation of delamination within the material was inhibited.…”

“…Hogg [96] observed that the CAI strengths of carbon/epoxy laminates manufactured using the VARTM process improved when toughened with polyester, carbon or hybrid polyester/carbon fibre veils. This was attributed to the same effect as seen by Walker et al [114], whereby there is a greater resistance to damage propagation than damage formation. As the impact damage area was approximately the same for all laminates, the veils arrested delamination growth during compressive loading.…”

“…This was attributed to the fibres being too long, hence there were insufficient fibre ends to contribute significantly to the fibre bridging effect during the propagation of delaminations whilst the laminate was in compression. Similarly, Walker et al [114] found that carbon/epoxy prepreg laminates interleaved with short PA fibres displayed much less visible impact damage. Interleaving was found to generate localised damage whilst the unmodified laminate had significant global damage suggesting that the fibrous veils contribute more to arresting damage propagation rather than preventing damage formation.…”

The influence of hybridization on impact damage behavior and residual compression strength of intraply basalt/nylon hybrid composites

“…The maximum deflection results in Table 4 confirm this suggestion. The impact response of each system can be qualified by calculating the established value of damping index [30,31]. The results of the damping index show that at low impact energy, hybridization and variation in basalt/nylon fiber content cannot improve the impact performance of composite plates.…”

Experimental optimization of the impact energy absorption of epoxy–carbon laminates through controlled delamination

“…When a composite structure is impacted, delamination often occurs, which seriously reduces the load bearing capacity of the laminate especially under compressive loads [5]. Therefore, several methods have been developed to improve the interlaminar strength and interlaminar fracture toughness of composite laminates, such as matrix toughening [6][7][8][9], through-thickness stitching [10][11][12][13][14], Z-pinning [15,16], and interleaving [17][18][19][20][21][22][23][24][25] and short-fibre interlaminar reinforcement [25]. Most of the above mentioned methods have been reviewed by Kim and Mai [26], who also pointed out the key role played by the fibre-matrix interfacial shear strength in determining the interlaminar resistance of composite laminates.…”