Understanding the effect of pressures, strain rates, and temperature on the strength of materials is vital in high-velocity impact applications such as ballistic impact, micrometeoroid impact, planetary impact, and inertial confinement fusion.  We utilize pressure shear plate impact experiments to investigate the effect of pressure, strain rate, and temperature on the strength of various materials. Using the data, we develop constitutive material models. To understand the atomic scale deformation process in shock compression, we utilize an ultra-high-speed X-ray diffraction facility in DCS at Argonne National Laboratory 

Materials in hypersonic flights and space applications are subjected to micrometeoroid or microparticle impacts which can be detrimental to the structural integrity and achieving space mission goals. In this research, we are developing experimental tools to accelerate particles of size ranging from 10 µm to 2000 µm to velocities close to 8 km/s by using high-power lasers/two-stage powder-gas guns to investigate the damage evolution in advanced materials under such extreme loading conditions. We use ultra-high-speed imaging and interferometric techniques to quantitively characterize the damage evolution in materials at unprecedented lengths and time scales. The damage model developed based on these experiments will be implemented in PISALE (Pacific island structures adaptive mesh refinement with arbitrary lagrangian eulerian hydrocode).

Experimental investigation of materials under dynamic compression is mainly devised with macroscale measurements. However, such macroscopic experiments are insufficient to elucidate the multiscale mechanisms that constitute the continuum behavior. Therefore, developing physics-based models for the dynamic compression of solids is challenging. We explore the connection between atomic, micro, and macro length scales deformation and failure mechanisms using advanced techniques such as X-ray diffraction and high-speed digital image correlation. These unique experiments help develop accurate multiscale models for predicting material behavior under extreme loading conditions.

Mechanical metamaterials are designed and engineered to exhibit novel mechanical properties and functionalities. These materials are manufactured at scales ranging from ‘nm to mm’. Most of the current studies of metamaterials are predominantly focused on the low strain rate regimes, and under dynamic loading conditions, it is limited to wave propagation and acoustic properties. There is a wide gap and a need to understand the strain rate dependence and the energy absorption characteristics of these materials in the high strain rate and high-pressure regime. We are interested in developing materials for impact energy dissipation and tailoring strain rate-dependent strength of these materials for impact/blast mitigation.