Investigation of low-velocity impact behaviors of polymer composites reinforced with different natural fiber fabrics

Abstract

In this study, the low-velocity impact behavior of polymer composites produced separately by reinforcing with natural fiber fabrics such as linen, hemp, jute, and bamboo was investigated for three different thicknesses (2.5 ± 0.1, 5 ± 0.1, and 7.5 ± 0.1 mm) by vacuum infusion method. Low-speed impact tests were performed at three different energy levels of 20, 35, and 50 J by striking the geometric center of the composite samples with a hemispherical impactor. The impact strengths of the composites were evaluated by comparing the contact force-displacement, contact force-time graphs, and impacted sample images. The types of damage occurring in each experimental sample were evaluated. Increasing the thickness had a positive effect on the impact strength of the composites. When the thickness of the composite plates increases, the peak contact force increases, the displacement decreases and capacity to carry impact loads increases due to the increased stiffness of the composites. However, except for the damaged 5 ± 0.1 mm thick bamboo and jute samples, the energy absorption ability of the samples generally increases with the increase of impact energy. Bamboo, jute, and hemp reinforced samples with a thickness of 2.5 ± 0.1 mm were completely perforated under 20 J impact energy. Also, it was determined that linen reinforced composites have the best impact resistance among natural fabric reinforced composites. Highlights: Low-velocity impact behavior of natural fiber fabric reinforced PMCs was studied. The impact strength of PMCs increased as the thickness increased. Linen reinforced composites had the best impact resistance. The main damage modes are matrix cracking and delamination at low-impact energies. As the impact energy increases, perforation and fiber breakage or separations are observed.