Effect of shape and obliquity of projectiles on the ballistic response of sandwich structures with carbon/epoxy face sheet subjected to low-velocity impact

Abstract

Low-velocity ballistic analysis of sandwich structures having carbon/epoxy plate and 5083- H116 aluminium alloy as face sheet and honeycomb core respectively was conducted. Effect of obliquity and shape of the projectile on the ballistic parameters such as stress build-up and the displacement of the sandwich, variation in the velocity of the projectile during the impact and the strain energy accumulation of the whole system was studied. The effect of the shape and obliquity of the projectile impacting a sandwich structure is the central theme of the article. A sharp projectile striking the sandwich panel perpendicular develops a large stress build-up on the sandwich structure. However, like the obliquity and shape of the projectile changed the stress build-up showed a very uneven pattern. The importance of the effective area of the projectile in contact with the sandwich panel plays a more important role than the profile of the projectile. The high strength and stiffness of the carbon/epoxy composite face sheet, caused the projectiles to recoil for all the obliquity and shapes projectile. An important observation was made, whrevealedlled that the displacement of the neighbouring elements has an appreciable effect on the displacement of the impacting point. The neighbourhood undulation resulted in the non-zero displacement of the impact point starting from the beginning of the impact analysis. Carbon/epoxy composite showed a good strain energy absorption capacity before failure..Experimental validation of the numerical finding will be available to the reader in a short time.