Analysis of Low-Velocity Impact Resistance of Carbon Fiber Reinforced Polymer Composites Based on the Content of Incorporated Graphite Fluoride

Abstract

As a graphite derivative, graphite fluoride (GrF) has a remarkable fracture toughness improvement effect on epoxy materials. The fracture toughness variation of the epoxy could exert an influence on the low velocity impact resistance of the corresponding carbon fiber reinforced polymer (CFRP) composite. Therefore, the dependence of the low velocity impact resistance of the incorporated CFRP on the GrF content is worth analyzing. Here, different contents of GrF were applied to incorporate CFRP laminates and planned to find the optimal GrF content, in turn leading to the best impact resistance. Using a drop-weight impact test, the load vs. time curves and load vs. displacement curves were obtained. The incipient damage loads and maximum loads of various GrF contents of the samples were compared carefully. The absorbed energies during the impact process were calculated. The trend of absorbed energy decreased up to the 1 wt% sample, then increased significantly with the rise of GrF content. This deflection behavior can be explained by the combination of crack pinning, crack deflection and crack propagation, due to the rise in GrF content. Through the ultrasonic C-scan evaluation, the delamination areas of different GrF content of samples were measured. The trend of delamination area variation was accordant with the trend of absorbed energy variation. This presents a demonstration of the correlation between the absorbed energy and the damage level. The SEM images of the fracture surfaces were analyzed for the deflection behavior of the fracture toughness with various GrF contents. The plot of residual compression strength versus GrF content further indicated the 1 wt% was the optimal content at which the incorporated GrF endowed the most impact-resistant property to the CFRP laminates.

The effect of simultaneous heat/fire and impact on carbon fibril and particle release from carbon fiber‐reinforced composites

“…The internal damage under the surface is harder to inspect, but degrades the mechanical property of the structure and may lead to a sudden failure when the materials are in service. [1] Major damage modes include matrix cracking, fiber/matrix debonding, delamination, inter-laminar failure and fiber breakage. [1][2][3] Moreover, due to the brittle nature of epoxy matrix, the overall impact resistance of the composite is lower than other structural materials, [4] including carbon fiber reinforced thermoplastic composites.…”

“…[1] Major damage modes include matrix cracking, fiber/matrix debonding, delamination, inter-laminar failure and fiber breakage. [1][2][3] Moreover, due to the brittle nature of epoxy matrix, the overall impact resistance of the composite is lower than other structural materials, [4] including carbon fiber reinforced thermoplastic composites. [5][6][7] Quite often thermoplastic polymers such as polyethersulphone are added in the epoxy resin to improve its toughness.…”

Experimental study on anti-freezing and thawing performance of basalt fiber reinforced fly ash concrete under corrosive conditions

“…Besides, some developing countries, such as Brazil, India, Russia and other emerging economies, have adopted catch-up strategies and formulated plans in the fields of new energy materials, energy-saving and environmental protection resistance and durability of NC are all improved. Besides, the improvement of these properties doesn't only depend on mechanical properties between fly ash concrete substrate and basalt fiber, but also are influenced by the content of basalt fiber and the degree of uniform distribution in the concrete substrate [8][9]. At the same time, the incorporation of fly ash into concrete can play its micro aggregate effect, morphological effect and activity effect, which strengthens basalt fiber concrete.…”

Experimental Investigation of Impactor Diameter Effect on Low-Velocity Impact Response of CFRP Laminates in a Drop-Weight Impact Event

“…Its vulnerability to low velocity impact events will induce Barely Visible Impact Damages (BVID) in the composite structures, which is manifested mostly by delamination and matrix crack with limited fiber breakage [3][4][5] that cannot easily be detected macroscopically. BVIDs pose significant safety issues since they are capable of generating extended damage and decreasing the residual strength and durability of the structure, which may cause catastrophic failure [6][7][8].…”