Fracture Mechanism Comparison of Fiber-Reinforced Ballistic Composites with Different Reinforcement Stacking Configuration Using Finite Element and Experimental Analysis

Abstract

Conventional ballistic layering system consists of both the disruptor layer which is made up of stronger synthetic fiber reinforcements such as ultra-high molecular weight polyethylene (UHMWPE) and the tougher absorber layer which is composed of other polymeric and natural fibers such as pineapple leaf and abaca fibers as partial substitute reinforcements. However, the ballistic performance of composites having different stacking sequences vary greatly as measured by the degree of bullet penetration (DOP), and back face signature (BFS) of composite plates. This study investigates the fracture mechanism of the UHMWPE-natural fiber-reinforced composites having the conventional disruptor-absorber stacking configuration and the sandwich stacking sequence. Numerical simulations of the ballistic performance of composite plates having different amounts of UHMWPE, PALF, and abaca were conducted to show the fracture mechanism of each composite setting. The simulation results were verified by assessing the actual DOP and BFS of the composites. Composite plates having disruptor-absorber configuration of 30 layers of UHMWPE + 2 layers of PALF, and 30 layers of UHMWPE + 7 layers of abaca, as well as the plates with sandwich stacking sequence of 15 layers of UHMWPE + 2 layers of PALF + 15 layers of UHMWPE, and 15 layers of UHMWPE + 7 layers of abaca + 15 layers of UHMWPE were fabricated via vacuum-assisted resin infusion and was later tested via ballistic penetration test to validate the numerical modeling and simulation. The actual ballistic penetration test matched the modeling and simulation results. Moreover, the plates with the conventional disruptor-absorber layer configuration show better ballistic performance as reflected in their DOP and BFS readings as well as their fracture mechanisms.