2022-04-06 08:00:00
Most brittle solids of engineering and scientific interest have heterogeneous microstructures— comprised of a polycrystalline matrix interspersed with micro-scale defects such as cracks, second-phases, precipitates, grain boundaries, and pores. These heterogeneities (“defects”) are often initiators of micro-cracking which results in damage-induced softening and non-linearity…
Normal (NPI) and/or combined Pressure-shear (PSPI) plate impact experiments are often employed for studying the macroscopic response of polycrystalline metals under dynamic loading. However, even for high symmetry metals such as Aluminum, their single-crystalline response is inherently anisotropic leading to significant uncertainty in dynamic…
Measuring and understanding the dynamic failure mechanisms of materials based on microstructural observations is paramount in our effort to design materials from the ground up with predictive and tailored properties. This necessitates the use of reliable high-throughput material testing systems and methods. Herein we…
Hot pressing of boron carbide with silicon carbide additives (5 – 25 wt.%) leads to the formation of a composite material, the matrix phase of which is close in stoichiometry to boron carbide, but contains a small amount of silicon, which can partially replace…
A robust porosity-mechanics-based constitutive model, suited to large-deformation three-dimensional simulations, has been previously developed [http://dx.doi.org/10.1063/1.4971654]. Simulations of plate impact experiments are performed, with a multilayer flyer configuration that produces two shocks. Experimentally observable results such as the temperature and velocity histories are compared to…
In this work, shear localization resulting from pore collapse is studied, in potential relation to damage and failure mechanisms under shock compression. Ti-6Al-4V specimens, with cylindrical and spherical pores were manufactured using additive manufacturing, and a soft catch set-up was used to enable post-mortem…
In this work, we present theoretical extensions to the TEPLA model for dynamic ductile failure of polycrystalline metals. The modified TEPLA model is equipped with a new robust solution strategy applicable under large deformation and general multiphysics conditions. We demonstrate the applicability of the…
Polymers often display mechanical properties that are vastly different, and frequently more complex, than metals but have historically received much less attention and study. There remain substantial gaps in our knowledge of polymer mechanics in extreme environments, including void nucleation and growth at high…
We have performed 3D finite element calculations of electro-magnetically collapsing thick-walled cylinders in order to investigate the role of porous microstructure on dynamic shear localization. The geometry and dimensions of the cylindrical specimens are taken from the experiments of Lovinger et al. (2015), and…
The response of porous materials under shockwave is of ongoing interest for various industrial and military applications (dynamic compaction of powders, design of blast mitigation devices, collision processes in the solar system, …). In addition, due to the development of additive manufacturing, the design…
