Impact Response of Elastic and Elastic-Plastic Sandwich Beams

An original model for impact analysis of elastic-plastic sandwich beams is presented, and the effect of sandwich damping is uniquely introduced in the analysis by considering the gradient of beam compliance. By incorporating the compliance (or stiffness) and compliance gradient of the sandwich beams to the equation of motion of the projectile, the standard mass-spring model for the sandwich system is uniquely recovered. Both the elastic and elastic-plastic impact processes are analyzed and compared with elastic model of no sandwich damping effect. The proposed impact model is validated with the elastic finite element analysis using LS-DYNA. A parametric study on the influences of velocity and mass of the projectile on the impact response of elastic and elastic-plastic sandwich beams is conducted, and it reveals the significant contribution of the sandwich damping and plasticity to the impact response.