Shock Mitigation With Ordered Microscale Granular Media
Abstract
The technical objective of the proposed effort is to utilize a combined theoretical, computational, and experimental approach to study high strain rate shock wave propagation in, and the resulting failure of, self-assembled, three-dimensional granular media. The proposed effort seeks to achieve the stated technical objective through combined numerical and experimental methods, using a four-part approach: (1) Discrete element model (DEM) simulations will be used to investigate shock wave propagation in ordered microscale granular media, using codes based on nonlinear microscale contact mechanics models that incorporate adhesive forces. The DEM will also be coupled to a Newton-Raphson numerical continuation model to predict the existence and stability of nonlinear localized modes. (2) Three-dimensional ordered microscale granular structures will be fabricated using layer-by-layer convective self-assembly techniques. (3) Photoacoustic pump-probe techniques will be utilized to study high-strain rate dynamic phenomena leading to the absorption of shock energy in, and the subsequent failure of, ordered microscale granular materials. The proposed photoacoustic techniques have a measurement amplitude of <0.5 pm, <1 ns temporal resolution and ~1 micrometer lateral spatial resolution. (4) Post-damage analysis will be performed for microsphere samples that have undergone sufficient shock loading to reach the point of failure. Cross sections of 3D geometries will be created using focused ion beam (FIB) milling.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510030
Entities
People
- Nicholas Boechler
Organizations
- Army Contracting Command
- United States Army
- University of Washington