Assessing the compression after impact behaviour of innovative multifunctional composites

Abstract

In the present work, the synergistic effect of multiwalled carbon nanotubes and glycidyl polyhedral oligomeric silsesquioxanes on the compression after impact behaviour of multifunctional carbon fibre-reinforced epoxy composite plates is investigated. For the qualitative evaluation of the damage accumulation after impact, non-destructive ultrasonic C-scan tests were performed. The impact-induced material degradation was correlated with data obtained from C-scan graphs through applying the concept of the damage severity factor. The test results obtained from C-scan analysis have shown a significant increase of the damaged area after the impact tests, as compared to the unfilled material considered as 'reference'. A reduced compression after impact strength is observed for the enhanced material as compared to the reference material. To identify the type of damage, optical microscope, scanning electron microscope and energy dispersive spectroscopy analyses were made after the tests. The optical microscope analysis has shown more extended cracking and delaminations for the enhanced material. Scanning electron microscopic analysis has revealed the presence of carbon nanotube agglomerates and possible glycidyl polyhedral oligomeric silsesquioxanes aggregates which might be the cause for a degraded compression after impact behaviour of the multifunctional composites.

Assessing the Damage Tolerance of Out of Autoclave Manufactured Carbon Fibre Reinforced Polymers Modified with Multi-Walled Carbon Nanotubes

“…This situation indicates that the nano-doped specimens have a higher damage tolerance compared to the baseline material. Pantelakis et al [15] investigated the synergistic effect of multi-walled carbon nanotubes on the after-impact behaviour of carbon/ epoxy composites revealing a significant increase of the damaged area and a reduction of CAI strength of nano-modified composites. Umer et al [16] proposed the introduction of graphene oxide by resin infusion process without negligible effect on the impact response of the nano-modified composites.…”

Out of autoclave manufacturing of CFRPs having multiscale reinforcement for improved interlaminar fracture toughness and multifunctional characteristics

“…This situation indicates that the nano-doped specimens have a higher damage tolerance than the baseline material. Pantelakis et al [75] investigates the synergistic effect of multi-walled carbon nanotubes on the after-impact behavior of carbon/ epoxy composites revealing a significant increase of the damaged area and a reduction of CAI strength of nano-modified composites. According to the author, the presence of carbon nanotubes agglomerates may act as stress concentrators rather than as reinforcement.…”