Abstract
Natural fibre composites are of interest for a wide range of semi-structural applications in the building, construction and automotive sector. For a number of these applications, the evaluation of performance degradation after impact is of some relevance. The present work focused on the influence of fibre volume fraction and fibre surface treatment on the residual load-bearing capability of hemp fibre-reinforced sheet moulding compound (H-SMC) after non-penetrating impacts. Post-impact flexural strength and stiffness of H-SMC decreased linearly with increasing impact energy. At higher impact energy levels, the residual flexural strength of H-SMC improved with increasing fibre volume fraction. However, for the same amount of absorbed energy, the residual strength or damage tolerance capability of glass fibre-reinforced sheet moulding compound was about twice that of H-SMC. Composites based on surface treated hemp fibres showed a slight improvement in residual flexural strength, particularly for systems based on hemp fibres treated with a combined alkaline and silane surface treatment. Surface treated systems showed improved levels of adhesion and increased levels of energy absorption through potential mechanisms such as debonding, pull-out or fibre fibrillation.
Highlights
Over the last few decades, numerous studies have been devoted to the use of natural fibres as alternative reinforcements to glass fibres in semi-structural composites.[1,2,3,4,5,6] Natural fibres like flax, hemp, jute or kenaf offer a number of advantages over glass fibres that make them attractive reinforcements for plastics
Damage tolerance studies where mechanical properties are evaluated after impact are essential in structural aerospace composites but have some relevance in natural fibre composites (NFCs) when used in semi
The peak force for all six incident impact energy levels occurs within a time frame of approximately 1.5–3 ms
Summary
Over the last few decades, numerous studies have been devoted to the use of natural fibres as alternative reinforcements to glass fibres in semi-structural composites.[1,2,3,4,5,6] Natural fibres like flax, hemp, jute or kenaf offer a number of advantages over glass fibres that make them attractive reinforcements for plastics They are abundant and of low cost, have a low density and as a result high-specific mechanical properties. They are non-abrasive to processing equipment, possess good insulating properties, are renewable, biodegradable and can be incinerated with energy recovery at the end of their lifetime These fibres provide social-economic advantages like job creation in the agricultural sector and can, for the right sort of application, reduce the overall environmental impact of composite parts.[7,8]. Damage tolerance studies where mechanical properties are evaluated after impact are essential in structural aerospace composites but have some relevance in NFC when used in semi-
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
