#Isale tillotson eos code

We used a planar 2-D Eulerian frame of reference Improvements include a modified strength model

Various equations of state (EoS), and multiple materials Materials, SALE was modified to include an elasticplastic constitutive model, fragmentation models, Simulate hypervelocity impact processes in solid Hydrocode solution algorithm (Amsden et al. Of metals or iron sulfides phases with minimum melting Shock-darkening pressure range for the onset of melting Thermodynamic processes and assessed melt fractionsįor each integrated mineral phase.

We modeled shock compression in heterogeneous Propagation of a shock wave in OC-like samples. 2013) to quantify processes related to the Principles of shock physics (Melosh 1989 Zel’dovichĪnd Raizer 2002) and hydrocode modeling (CollinsĮt al. Shock-darkening may be a consequence of shockĬompression and associated heating. The dashed line indicates the 1 and 2 lm bands. Description of the light and shock-darkened lithologies of two samples taken from the Chelyabinsk LL5 meteorite and To evaluate under optical microscopy because theįig. 1991) of the silicate material is difficult Melt veins can intercalate between the shocked solid A few percent of silicate meltįorms melt pockets. Pyroxenes are found to be highly shocked but not In contrast, silicates such as olivine and 1992)Īnd more recently in the Chelyabinsk LL5 OC (KohoutĮt al. Volumes of OC material and it has been observed inĮarlier reports on OCs (Heymann 1967 Britt and Silicate grain boundaries and cracks to form a network Shock-darkening, or shock-blackening, in ordinaryĬhondrites (OCs) is the process that involves melting of Observed in gas-rich OCs, Britt and Pieters ). Occurring on asteroid surfaces (space weathering, ClarkĮt al. However, shockdarkening should not to be confused with darkening That some C/X-complex asteroids may, indeed, be shockdarkened S-complex asteroids (Britt and Pieters 1989 īritt et al. With asteroid spectra classification and distributions Meteorite light lithology spectra resemble that of Scomplex asteroids while the dark lithology spectra areįlatter and darker and appear similar to some C/Xcomplex asteroid spectra. Spectra of meteorites as seen in the Chelyabinsk This process has a significant effect on reflectance Our workĪims to study the pressure range at which shockdarkening occurs. Shock-darkening turns the material opaque. We also discuss possible notshock-related triggers for iron melt.

#Isale tillotson eos code

The porosity models available in the iSALE code are discussed. Heating in iron and also the importance of porosity. In the troilite material reach the melting point. Melt, happened between 40 and 50 GPa with 52 GPa being the pressure at which all tracers Results showed that shock-darkening, associated with troilite melt and the onset of olivine Melting point) for each material were estimated after the passage of the shock wave andĪfter the reflections of the shock at grain boundaries in the heterogeneous materials. The postshock temperatures (and the fractions of the tracers experiencing temperatures above the Used Lagrangian tracers to record the peak shock pressures in each material unit. We used equations of state (Tillotson EoS andĪNEOS) and basic strength and thermal properties to describe the material phases. Porous olivine matrix in the sample layer. Iron and troilite grains were resolved in a Sample layer at different nominal pressures. We simulated planar shock waves on a mesoscale in a E-mail: 15 September 2016 revision accepted 27 June 2017)Ībstract–We determined the shock-darkening pressure range in ordinary chondrites using Ur Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, GermanyĬorresponding author. Institute of Geology, The Czech Academy of Sciences, Prague, Czech Republic Shock-darkening in ordinary chondrites: Determination of the pressure-temperatureĬonditions by shock physics mesoscale modelingĭepartment of Physics, University of Helsinki, Helsinki, Finland Meteoritics & Planetary Science 1–16 (2017)