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.

天然纤维复合材料在建筑，建筑和汽车领域的半结构化应用中引起广泛关注。对于这些应用中的许多应用而言，评估撞击后的性能下降具有一定意义。目前的工作集中于纤维体积分数和纤维表面处理对非穿透冲击后大麻纤维增强片状模塑料（H-SMC）的残余承载能力的影响。H-SMC的冲击后弯曲强度和刚度随冲击能量的增加呈线性下降。在较高的冲击能水平下，H-SMC的残余挠曲强度随纤维体积分数的增加而提高。但是，对于相同量的吸收能量，玻璃纤维增​​强的片状模塑料的残余强度或破坏耐受能力约为H-SMC的两倍。基于表面处理的大麻纤维的复合材料在残余挠曲强度方面略有改善，特别是对于基于经过碱和硅烷表面处理相结合处理的大麻纤维的系统。经过表面处理的系统通过潜在的机制（如脱粘，拉出或纤维原纤化）表现出更高的附着力水平和更高的能量吸收水平。