Impact Performance of Hybrid Sandwich Composites with Synthetic Fiber Skin and Natural Fiber Core

This study aims to examine the high-velocity impact (HVI) on sandwich composite panels made of bidirectional synthetic fiber skin (Dyneema) and unidirectional natural fiber core (jute). HVI refers to the interaction of structures with lower mass projectiles traveling at high velocities, a phenomenon often relevant to aerospace, automotive, and ballistic applications. Four laminates were manufactured for different configurations of core for example, [0°]8, [0°/90°]4, [±45°]4, and [0°/90°/±45°]2. During the laminate fabrication, epoxy resin was used. Each laminate consists of two layers of Dyneema fibers as skin (top and bottom) and eight layers of natural fibers as core while having the same thickness. The laminates were subjected to HVI testing to evaluate energy absorption, and the ballistic limit was determined using logistic regression to estimate the 50% probability of penetration (V50). Experimental results revealed that the [0°/90°/±45°]2 stacking sequence achieved the highest energy absorption among Dyneema skin/jute core configurations, showing a 59.47% improvement compared to the unidirectional core. Ballistic analysis indicated that the 50% probability of penetration occurs at a kinetic energy of 158.56 J for the Dyneema skin/jute core laminate with a [0°/90°]4 stacking sequence, highlighting the superior ballistic resistance of this configuration. The study underscores the significance of core orientation and material selection in enhancing the energy absorption and ballistic resistance of sandwich composite panels, with implications for their use in high-impact and protective applications.