Artículo de revista
Onset of failure in argon by the effect of a shockwave: A molecular dynamics study
Fecha
2010-06-26Registro en:
COMPUTATIONAL MATERIALS SCIENCE, Volume: 49, Issue: 3, Pages: 582-587, 2010
0927-0256
Autor
Loyola, Claudia
Davis, Sergio
Peralta, Joaquín
Gutiérrez Gallardo, Gonzalo
Institución
Resumen
Molecular dynamic simulations of shockwaves in solid argon were performed. The simulation cell contains
51,840 atoms at 5 K interacting by means of a pairwise potential. The shockwave itself was introduced
explicitly in the simulation by a piston hitting the sample from one side of the simulation box, at
speeds ranging from 1.2 to 1.3 times the speed of sound in solid argon at the chosen density. In order to
characterize the sample in terms of both structural and dynamic properties, we determine the density
and temperature profiles according the advance of the shockwave, evaluating, for different slabs, the
pair–distribution function, coordination number as well as performing a common neighbor analysis for
the atoms. Our simulations reproduce the experimental Hugoniot curve and show how the material is
break due to rarefaction waves. The picture that emerges is that when the shockwave starts, a local melting
is produced in a region of the sample. Then, as the shockwave travels through the sample, a high density
disordered phase is identified. When the piston stops, a rarefaction wave develops, producing a large
tensile stress, which finally causes the failure of the sample.