Investigation of High Velocity Impact Responses of a Glass/Epoxy Composite with a Gas Gun

摘要

The single stage gas gun testing methodology was investigated. To provide datafor computational model development, quantitative measurements of force anddisplacement were attempted. The transmitted impact force was measured with fourload cells installed behind the target. The out-of-plane deformation was measured witha projection grating profilometry method using a high speed camera. The velocity ofthe projectile was determined using images from the high speed footage. The forceand deflection measurements were successful for tests conducted below the ballisticlimit. The improved gas gun experiment was used to investigate the high velocityimpact behavior of a S2-glass/SC15 epoxy composite. The ballistic limit was found tobe 329 and 381 m/s for the 3.8mm (6-ply) and 6.2mm (10-ply) composite panels,respectively. The failure modes of the composite panels were inspected with backlight.The area of damage and failure was found first to increase and then become localizedwith increasing velocity. As a result, the panels absorbed the same or even a slightlyhigher amount of energy beyond the ballistic limit, until damage localization. Finally,a new method to compare the ballistic protection capability of different materials ispresented.