Perforation of composite plates and sandwich panels under quasi-static and projectile loading

Analytical solutions for the deformation, penetration, and perforation of composite plates and sandwich panels subjected to quasi-static punch indentation and projectile impact are derived. Discrete spring-mass models are used to calculate the impact response of the composite plates and sandwich panels. Equivalent load resistance functions are obtained from the quasi-static analysis and adjusted for high strain rate. A generalized solution methodology for projectile impact of composite plates and sandwich panels are then proposed based on three key factors: (i) the contact load duration, (ii) the through-thickness transit time, and (iii) the lateral transit time. A two-dimensional wave propagation model is used to determine the ballistic limits of E-glass/polyester panels and GLARE fiber metal laminates, and predicted values are found to be within 20 and 13% of the experimental results, respectively. A quasi-static impact model is used to predict the ballistic limit for E-glass/epoxy-aluminum honeycomb sandwich impacted by hemispherical nose projectile and the predicted values are within 11% of test results.