Thursday  |  Salon 10  |  09:20 AM–09:40 AM

#15629, Dynamic Response of a Lattice Infilled Columnar Granular Chain

Stress wave propagation in granular media has been extensively studied due to their unique wave dynamics. Previous work has primarily focused on understanding the influence of defective grains such as grains with varying mechanical properties on the dynamic response of the overall system. With the advent of additive manufacturing, structures with unique lattice geometries have also been extensively studied due to their novel energy absorption behavior to realize a new class of impact-absorbing metamaterials. In this work, we present the dynamic behavior of a columnar granular chain composed of cylindrical grains infilled with various lattice structures. Grains are additively manufactured using PLA as the base material by fused filament forming. A custom drop-tower setup is utilized to understand the dynamic response of the columnar chain. Deformation of the particles is tracked by a high-speed camera operating at 40,000 fps frame speed and the kinematic and strain fields in each particle are calculated using digital image correlation (DIC). Results from quasi-static and low-velocity impact experiments quantify the influence of the type of internal geometry of the grain on its mechanical response. Finally, we present numerical studies that elucidate the influence of geometric parameters of the lattice unit cell on the static and dynamic response of the grain and the granular chain, respectively. These studies enable the identification of optimal geometric parameters to achieve a targeted mechanical response under impact loading.

Prajwal Bharadwaj   Worcester Polytechnic Institute
Nikhil Karanjgaokar   Worcester Polytechnic Institute