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In the present study, impact behavior of Kevlar/Epoxy composite plates has been carried out experimentally by considering different thicknesses and lay-up sequences and compared with analytical results. The effect of thickness, lay-up sequence on energy absorbing capacity has been studied for high velocity impact. Four lay-up sequences and four thickness values have been considered. Initial velocities and residual velocities are measured experimentally to calculate the energy absorbing capacity of laminates. Residual velocity of projectile and energy absorbed by laminates are calculated analytically. The results obtained from analytical study are found to be in good agreement with experimental results. It is observed from the study that 0/90 lay-up sequence is most effective for impact resistance. Delamination area is maximum on the back side of the plate for all thickness values and lay-up sequences. The delamination area on the back is maximum for 0/90/45/-45 laminates compared to other lay-up sequences.

This work examines the experimental and analytical investigation of impact on the carbon/epoxy laminates of various stacking sequence. The impact tests were carried out by using gas gun equipped with high-speed camera. Projectile velocities selected were 80 m/s and 30 m/s where 80 m/s was above ballistic limit velocity and 30 m/s was below ballistic limit velocity. The impact process was recorded with high-speed camera which facilitated to identify different energy absorbing mechanisms. High-speed images were also used to measure pre-impact and post-impact velocities of the projectile accompanied by photo diode and aluminum foil method. Total energy absorbed by the laminates, which is the difference between pre-impact and post-impact kinetic energy of the projectile, was calculated for the laminates with different stacking sequences. Damage extent in the laminates of different stacking sequences were also assessed by C-Scan of the laminates. Then effect of stacking sequences on damage extent and energy absorbing capacity was established. An analytical model was proposed to predict the residual velocity of the projectile at above ballistic limit velocity, which was based on the total energy absorbed by different energy absorption mechanisms. The analytical model was validated with experimental results for different stacking sequences. Additionally, effect of fiber orientation on damage shape at below ballistic limit velocity was also studied.

Glass/epoxy composite laminates are subjected to impact loading and the energy absorbing capacity of the laminates is studied. In the present study, laminates with four different orientations and thickness values are considered. Analytical study is carried out based on energy method and results are compared with FE results obtained from Abaqus/Explicit software. Results obtained from the analytical methods are showing good agreement with the FE results. It is found that cross-ply laminates are most efficient in ballistic resistance when compared with the laminates of other orientations. It is also noticed that the energy absorbing capacity is decreasing with increase in velocity of the projectile for a given lay-up and thickness value.

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