2022-04-06 08:00:00
The overall response of elasto-viscoplastic polycrystals demonstrates non-Maxwellian, long-memory effects, while constituent single crystals show Maxwellian, short-memory behaviour. To characterize this emergent behaviour, this work presents analytical homogenization estimates for the elasto-viscoplastic polycrystals and demonstrate that large viscoplastic nonlinearity or anisotropy for the single…
Materials scientists developing novel solid phase processing methods require an atomic level understanding of deformation induced dynamic microstructural evolution. This same goal is also relevant to researchers interested in understanding how atomic locations in materials are modified from the initial state when exposed to…
Ductile failure is a multi-scale phenomenon. In metals, atomic deformation mechanisms interact with micromechanical length-scales defined by the size and distribution of microscopic defects to trigger damage through void nucleation and growth. Coarser length-scales appear with inter-void interactions that coalesce to form mesoscopic damage…
In a nuclear reactor, the reactor pressure vessel (RPV) serves as a critical safety barrier for preventing the release of radiation to environment during accident scenarios. RPV is made of Fe-base ferritic steels that may contain a small amount of insoluble copper. Under neutron…
A variety of methods were developed in the past to capture the microstructure evolution of metals, however, the numerical representation of slip and twin mechanisms is still posing a challenge to date. We discuss the advantages, drawbacks and limitations of existing approaches
Funding opportunities, in particular those that promote and support collaboration among academia, National Labs, and industry, will be discussed, with an emphasis on those pertaining to Materials and Structures in Extreme Environments.
Selective Laser Melting is an additive manufacturing (AM) process which uses high-powered lasers to rapidly melt and solidify metal powder into three-dimensional structures. The SLM process is highly complex and can have undesirable results such as stochastic defect formation and non-equilibrium microstructures. To fully…
Granular and other heterogeneous materials exhibit complex behaviors which are difficult to capture using classical continuum theories. Enhancements through higher order descriptions of the deformation such as micropolar or, most generally, micromorphic continuum have been proposed but suffer from difficulty in calibrating the numerous…
Calibrated radiometric light curves in three separate wavebands are presented for labscale hypervelocity impacts of an aluminum sphere onto aluminum targets conducted at Johns Hopkins University HyFIRE facility. The measured data is compared to synthetic light curves produced from a 3-D radiative transport software…
Planetary bodies in our solar system may have locations that could harbor life, and such bodies are subject to major impact events. It is unclear to what extent life can survive these impacts and, if so, whether they can be transferred to other planetary…
