SIMULATANEOUS IMPACT OF MULTIPLE PROJECTILES ON LAMINATED STRUCTURES

摘要

This paper will present the development of a novel test method that highlights a concept called Fragment Cloud Impact (FCI), in which a structure is subjected to normal impact by multiple projectiles at approximately the same time and velocity. This type of impact frequently occurs as a result of secondary blast debris, shrapnel (primary blast debris), and multiple bullet impact. The focus of the work is FCI to laminated composite structures. When laminated materials are subjected to ballistic impact, the material response is determined by interactions of multiple stress waves generated at the laminate interfaces. In the case of a simultaneous multiple projectile impact scenario, stress waves may interact with one another or with newly formed delaminations from adjacent projectiles, causing scattering and constructive/destructive interference. This may ultimately change the peak stress resulting in a change in the extent of internal and external damage. The increase in new surface creation (delamination) from simultaneous impact is assumed to be the key mechanism leading to an increase in energy absorption, in contrast to single projectile and sequential projectile impact events.