Ballistic response of woven glass fabric-epoxy composites at low temperatures: Experimental investigation

The ability of Glass Fabric Reinforced Polymer (GFRP) composites in arresting a projectile during a ballistic impact is dependent on climatic conditions such as temperature since their mechanical properties vary with the same. In the present work, ballistic impact experiments were carried out on plain weave GFRP composites to evaluate their performance in low-temperature environments. Square sheets of plain weave GFRP were impacted by cylindrical projectiles at four different temperatures viz. -35 degrees C, -15 degrees C, 0 degrees C, and at Room temperature. A gas gun was used to propel the projectiles and the velocities were measured using a High-speed camera while the temperatures were monitored using a Resistance Temperature Detector (RTD). Strain gauges were also attached at different locations on the samples to quantify the strains due to the projectile impact. The ballistic limit obtained from the test data was found to increase linearly with reducing temperature contrary to the general expectation of degradation in the ballistic performance of GFRP at low temperatures. The Lambert-Jonas equations were fit to the experimental data and the parameters were estimated. The results obtained also indicated a decrease in stress wave attenuation and an increase in tensile strains with the decrease in temperature.