2025-04-09 09:00:00
Automated high-throughput characterization is an essential enabling technology for autonomous materials research. Traditional microstructural characterization techniques, particularly those that require careful surface preparation, are difficult to adapt to a high-throughput environment. In contrast, transmission x-ray diffraction (XRD) provides the ability to probe bulk microstructure…
Dislocation motions in crystals govern the plasticity even under high strain rate deformations induced by shock waves. The maximum speed at which dislocations can move inside crystals have been controversial and a key unsettled question is whether dislocations can move faster than the transverse…
Achieving a breakthrough in Inertial Confinement Fusion (ICF) is dependent upon the homogeneous compression of a fuel capsule to form a central hot spot, crucial for reaching the necessary conditions of high temperature, pressure, and density needed for ignition. However, micro-voids within the fuel…
Plastic-bonded explosives (PBX) generally consist of microparticles and polymer binders. We want to see inside PBX as powerful shock waves pass through them. Unfortunately PBX strongly scatter light, so it is difficult to see inside them. Here I will focus on two applications. With…
High strength ceramics such as boron carbide (B4C) exhibit exceptional performance under impact up to the Hugoniot elastic limit (HEL), but apparent brittle failure after the HEL results in an immediate loss of strength prior to a rise to the peak Hugoniot state. By…
The modeling of physical mechanisms governing damage and fracture under extreme loading conditions has made remarkable progress in recent decades, driven by various industrial demands. However, numerous scientific questions remain unanswered. Particularly in the context of spallation, discussions persist around the interactions between pores…
The Air Force Research Laboratory has interests in increasing the mechanical resilience of highly loaded composite systems that must survive harsh thermomechanical environments. Mechanical failure is commonly induced and propagated in these materials at the interfaces between the matrix and particulate constituents. In this…
This extended abstract summarizes a previously developed approach for modeling high-velocity impact on multi-layered plain weave composites. This approach is evolved here to include a stochastic mesostructure, which more realistically models a real plain weave composite. The mesoscale modeling approach resolves plain weave architecture…
Cemented granular materials (CGMs) include ceramics, concrete, sandstone, and other sedimentary rocks. These materials have prominent roles in geophysics, engineering, and defense applications. However, due to their microstructural complexity, a complete understanding of the microscopic mechanisms governing macroscopic mechanical behavior in natural CGMs such…
Previous research has shown that the high strain rate performance of thermosetting polymer systems is strongly correlated to three characteristics: the relaxation behavior with respect to the polymer Tg, the molecular weight between crosslinks (Mc), and the fracture toughness (KIC). Using different thermosetting systems…
