2025-04-09 09:00:00
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…
The current materials research process is slow and expensive; taking decades from invention to commercialization. The Air Force Research Laboratory pioneered ARES™, the first autonomous experimentation system for materials development. A rapidly growing number of researchers are now exploiting advances in artificial intelligence (AI),…
Fundamental understanding of advanced-material performance under dynamic conditions has remained challenging due to cost- and time-intensive characterization. In many scenarios, prediction of these dynamic responses remains limited to modeling approaches, while comprehensive experimental validation sweeps are unattainable. Microscale dynamic characterization routes such as micro-Kolsky…
Since their rapid adoption over the last two decades, polyurea elastomer coatings have become an essential component in ballistic protection materials and armor coatings. Polyurea’s copolymer architecture forms microphase separated nanostructures of “hard” and “soft” domains that are rich and poor in hydrogen-bond forming…
The recent advent of machine learning and additive manufacturing allows us to design and manufacture complicated microstructures. Most current machine learning algorithms utilize simulated data due to limited developments in high throughput experiments. In this study, a fully automated split Hopkinson bar setup is…
The response of metals and their microstructures under extreme dynamic conditions can be markedly different from that under quasistatic conditions. Traditionally, high strain rates and shock stresses are hl{achieved} using cumbersome and expensive methods such as the Kolsky bar or large spall experiments. These…
The ongoing research on developing metal additives to conventional explosives is a complex multifaceted problem that we can address through material engineering. Fuel-oxidizer composite particles produced by arrested reactive milling (ARM) can react much faster than other additives since the metal fuel and oxidizer…
With increasing deformation rates, the thermally activated dislocation glide transitions to a continuous glide of dislocations influenced by their interactions with phonons. Understanding dislocation-phonon drag is critical for designing materials for extreme conditions, but remains largely qualitative due to the difficulty of measuring materials…
Refractory multi-principal element (RMPE) alloys possess remarkable strength retention at elevated temperatures, making them attractive for extreme structural environments. Several promising single-phase alloys demonstrate an intermediate temperature strength regime that is quasi-athermal, motivating studies that aim to link the temperature-dependent mechanical behavior to dislocation…
