Effect of stacking sequence on failure mode of fiber metal laminates under low-velocity impact

Abstract

In this study, the effect of stacking sequence on the impact behavior of fiber metal laminates under the drop weight impact test was investigated. Four groups of specimens with layups of [Al-(0/90)8-Al], [Al-(±45)8-Al], [Al-(0/90)4-(±45)4-Al] and [Al-(±45)4-(0/90)4-Al] were fabricated and tested. Fiberglass–aluminum composite specimens were made of Al 2024-O sheets and woven glass fabrics with epoxy resin. These specimens were tested using a drop weight impact testing machine with an energy of 44.13 J and speed of 3.43 m/s. The results obtained showed a higher load-bearing capacity before failure of the outer aluminum layer for specimens with [Al-(±45)8-Al] layups. Fiber metal laminates with [Al-(0/90)8-Al], [Al-(0/90)4-(±45)4-Al] and [Al-(±45)4-(0/90)4-Al] layups had lower load-bearing capacities than the first group of specimens, respectively. The form of damage progression in the second layer of aluminum of specimens was completely dependent on the stacking sequence of composite layers. Numerical modeling of the drop weight impact test was carried out using ABAQUS 6.9 software. A detailed analysis of the failure mechanisms in the aluminum layer has been presented. A comparison between experimental results and the numerical simulation was performed to verify the simulation procedure.