Mechanical and dynamic responses of unidirectional/woven carbon fiber reinforced thermoset and thermoplastic composites after low velocity impact

Abstract

It is highly important to determine how mechanical and dynamic properties of composite materials will change after impact loads considering the coupled effects of composite design parameters. For these reasons, three-point bending and vibration tests have been carried out for the carbon fiber reinforced thermoset and thermoplastic composites with various stacking sequences before and after low velocity impact, and it is expected that these results achieved from the current study will be beneficial for applications where high damping and impact resistance are demanded together. In this context, vibration tests were carried out under free-free boundary conditions, and their natural frequencies, flexural moduli and structural damping were obtained. Furthermore, three-point tests were conducted in the elastic region with 1 mm/min crosshead speed using a universal test machine, and thus flexural moduli of the composite specimens were obtained. The results were validated by comparing the flexural moduli obtained from the both vibration and three-point bending tests, found to be reliable and comparable. As a result of the current study, it was concluded that woven fabric reinforced composite specimens exhibited 50% higher specific damping capacity (SDC) but 70% lower flexural modulus than unidirectional specimens thanks to biaxially fiber alignment. On the other hand, specific damping capacities of the thermoset and thermoplastic composites with different stacking sequences have been examined, and it was observed that thermoset specimens exhibited unexpectedly 192% higher SDC compared to the thermoplastics. This was interpreted as even though thermoplastics are normally expected to exhibit more damping than thermosets, stacking sequence being more effective on damping responses. Apart from that, although there were slight changes in material properties due to degradation in structural integrity after 2 m/s and 3 m/s low-velocity impacts, it was not found to be significantly effective due to the limited damage areas.

The influences of low‐velocity impact loading on the vibration responses of the carbon/glass fiber‐reinforced epoxy composites interleaved with various non‐woven thermoplastic veils

“…This was attributed to the low areal weights of PI thermoplastic veils as well as their chemical compatibility with GFRP composites, and it was concluded that PI veil interleaves are not suitable for the application areas where high stiffness is required. Inherent damping can be defined as the energy dissipation within the structure, 39 and thermoplastic materials exhibit relatively higher damping due to their chemical structure and excellent energy absorption capacity. 38 These materials also exhibit high plastic deformation and ductility due to chain slippage during impact, which allows most of the applied energy to be encountered by thermoplastic materials, thus preventing serious damage to synthetic fibers.…”

“…Inherent damping can be defined as the energy dissipation within the structure, 39 and thermoplastic materials exhibit relatively higher damping due to their chemical structure and excellent energy absorption capacity 38 . These materials also exhibit high plastic deformation and ductility due to chain slippage during impact, which allows most of the applied energy to be encountered by thermoplastic materials, thus preventing serious damage to synthetic fibers.…”

Experimental Investigation of Influence of Fibre Orientation on the Dynamic Properties of Carbon Fibre and Intra-Ply Woven Carbon-Kevlar/Epoxy Hybrid Composite

“…The Kevlar-based fibre would be more advantageous as it has strong damping properties but a lower stiffness. Hybridisation is a trade-off that can be clearly used to obtain the balanced configuration to attain the desired properties [4][5][6][7][8].…”

Residual compressive strength of polyamide fiber‐reinforced epoxy composites after low‐velocity impact

“…[1][2][3][4][5][6][7][8][9][10] Glass-fiber, carbon-fiber and basalt-fiber composites achieved by mixing fibers with polymeric resin can be demonstrated as the most common examples. [11][12][13][14][15][16] These fiber-reinforced composite materials are extensively utilized in many engineering fields such as aerospace, aviation and automobile due to their high strength, lightweight, stiffness, resistance to environmental and corrosive factors, design originality and production advantages. [3,10,17,18] Especially, the use of fiber-reinforced plastics has been growing in the automotive field due to their high strength, good damping, stiffness and lightweight features.…”