Dynamic Response of Damping Estimation of Layered Plate Systems Under Shock Loading

Resonant plate shock testing is used in the Mechanical Shock Lab at Sandia National Laboratories to simulate pyroshock and other severe shock environments on aerospace components. At this time, damping is required in the resonant plate system to better match specified shock requirements. Current damping systems added to resonant plates, known as damping bars, can disrupt the desired plate modes, resulting in responding modes of the test system far from the design frequency. Alternative damping treatments could be beneficial in maintaining the desired modal response of the resonant plate. A prior study investigated the modal response (natural frequency and damping ratio) of layered square plate assemblies under typical experimental modal test conditions with an impact hammer. This work evaluates the response of layered plate assemblies under shock loading in addition to modal test loading. Shock loading is achieved via a projectile impact, which delivers an impulsive force much greater than achievable with impact hammer loading. A simple empirical model is developed and used to estimate the damping response of a layered resonant plate systems exposed to aerospace component test shock levels.