Ballistic impact resistance of carbon-fibre laminates

“…However, this phenomenon totally coincides with the observed properties. Thus, Rodgers et al [40] showed that despite the fact the composites reinforced with modified carbon fibers needed higher kinetic energy to cause any significant damage during ballistic tests, once this limit energy was reached, composites were destructed in a brittle manner, consequently absorbing much less energy compared with composites reinforced It was shown that the composites reinforced with initial fibers have an impact strength of 155 kJ/m 2 for composites with 70 wt.% of fiber content and 130 kJ/m 2 for 50 wt.% compared with 86 kJ/m 2 and 80 kJ/m 2 of the composites reinforced with modified fibers TO300 and TO500, respectively. Such behavior can be interpreted as abnormal, considering the better mechanical properties and fracture toughness of CFRP reinforced with treated CFs.…”

Section: Resultsmentioning

confidence: 98%

“…However, this phenomenon totally coincides with the observed properties. Thus, Rodgers et al [ 40 ] showed that despite the fact the composites reinforced with modified carbon fibers needed higher kinetic energy to cause any significant damage during ballistic tests, once this limit energy was reached, composites were destructed in a brittle manner, consequently absorbing much less energy compared with composites reinforced with initial fibers. The same results were presented in several studies where an inverse dependence between interfacial bonding strength and impact properties of CFRPs based on thermoset [ 41 ] and thermoplastic [ 30 , 31 ] polymers was found.…”

Section: Resultsmentioning

confidence: 99%

Influence of Interfacial Interaction and Composition on Fracture Toughness and Impact Properties of Carbon Fiber-Reinforced Polyethersulfone

Torokhov,

Chukov,

Tcherdyntsev

et al. 2024

Polymers

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In this study, the interlaminar fracture toughness and impact strength of polyethersulfone reinforced with continuous carbon fibers were studied. Interlaminar fracture toughness tests were performed using the double cantilever beam method. It was shown that surface modification using the thermal oxidation method of the carbon fibers can strongly increase the interlaminar fracture toughness of the obtained composites. Thus, the maximum value reached 1.72 kJ/m2, which was 40% higher than the fracture toughness of the composites reinforced with initial carbon fibers. Moreover, fractographic analysis using a scanning electron microscope allowed us to highlight the main reasons for the dependence of fracture toughness on fiber content and surface modification conditions of the carbon fibers. It was shown that the main factor that allowed for an increase in fracture toughness was the enhanced interfacial interaction between the fibers and polymer matrix. Additionally, it was found that expectedly, there was a good correlation between interlaminar fracture toughness and interlaminar shear strength results. However, a negative influence of surface modification on the impact properties of composites was found. Such behavior occurred because of higher structural stability and lower exposure to delamination in multiple layers of the composites reinforced with the modified carbon fibers. It was found that impact energy reached ~150 kJ/m2 for the polyethersulfone-based composites reinforced with initial fibers, while the composites reinforced with modified carbon fibers showed impact energy values of only ~80 kJ/m2. Nevertheless, surface modification of carbon fibers using the thermal oxidation method can be an effective method for improving the performance properties of polyethersulfone-based composite materials.

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“…Although these early impact investigations provided an insight into the various properties of composites, many authors [9][10][11][12][13] were having reservations as to whether Izod and Charpy impact tests were actually providing useful experimental data for the design of composite structures. This was because the test specimen geometries were unrepresentative of structural applications and therefore their validity for composite component design was unreliable.…”

Section: Early Impact Testsmentioning

confidence: 99%

“…In 1971, Rogers et al [9] used an air-gun to conduct high speed ballistic impact tests on square composite laminates, to determine if impact resistance could be improved by treating the fibre surface with sodium hypochlorite. The authors state that the air-gun proved to be a suitable experimental apparatus for the study of small particle impact on composite materials.…”

Section: Early Impact Testsmentioning

confidence: 99%