Static and nonlinear impact analyses of free-free sandwich plates on a solid half-space

In this study, an elastic model for static and nonlinear impact responses of a composite sandwich plate on an elastic half-space including the anti-plane core effect is developed. The effects of the elastic half-space and the anti-plane core are studied, and the contact force history and maximal deflection are predicted. Compared to the available analytical static analysis of rigid plates on a solid half-space and the numerical finite element modeling using LS-DYNA, the proposed theoretical method shows its validity and advantages in predicting the static and impact behaviors of sandwich plates sitting on a solid half-space. The predicted non-uniform distribution of transferred force under static load sheds new light on the understanding of force action mechanism between the sandwich system and the solid half-space. The two important impact factors (i.e., the maximal deflection and the peak contact force) provided by this study can be used to determine the damage size and position. Further, the semi-analytical model developed can be served as a basis for optimal design of fully backed sandwich collision protection systems, of which both minimizing the rebounded residual velocity of the projectile and keeping the underneath protected structures intact are important.