Investigating the fracture behavior and energy absorption of new flexible hybrid biocomposites with soft and hard layers of rubber/lignin/CB and hemp fabric impregnated with matrix under high-velocity impact

Abstract

Abstract This paper compares the behavior and energy absorption of hybrid and conventional flexible composites with soft and hard rubber layers and fabrics impregnated with soft and hard matrix in different configurations of layer arrangement under high-velocity impact. For this purpose, two types of hard and soft rubber layers were produced by increasing the amount of lignin-carbon binary filler in rubber compounds. Also, a diluted hard and soft rubber matrix was used to impregnate the hemp fabric. The high-velocity impact test was performed by firing a hemispherical projectile on the proposed composites at a velocity range of 80 to 160 m/s. The effectiveness of diluted rubber matrix coating and rubber layer in terms of projectile velocity reduction, damage mechanism, absorption of the kinetic energy of composites, and the effect of different layer configurations on residual velocity have been presented and investigated. The results show that elastomer hardness significantly affects the ballistic performance of flexible composites. Also, by examining the position of hemp fabric and rubber layers in the arrangement of layers, it is clear that better performance is obtained for a hybrid composite with hard layers on both sides of the impact face and a soft layer in the middle. The damage mechanism in composites with hard layers through small inlet and outlet diameters and more protective margins shows an excellent ability to absorb energy and subsequently reduce the residual velocity of projectiles.