ATOMISTICALLY-INFORMED MACROSCALE POROSITY MODELS

C. J. RUESTES; G. BERTOLINO; E. M. BRINGA

Bariloche

Congreso; ENIEF 2014; 2014

IB

Macroscale-derived porosity models might fail as pore size / ligament size approach thenanoscale. As an example, while the Hall-Petch law predicts an increase in strength as grain-sizedecreases, a breakdown in this law at the nanoscale has been observed. To make matters worse, manyconstitutive models do not take into account strain-rate effects, which are important in several extremescenarios, like hypervelocity impact or shock wave studies. Atomistic molecular dynamics (MD)simulations of nanofoams subjected to high strain-rate compression do not compare well withcontinuum level simulations using standard constitutive models of porous materials, like the Gursonmodel. Several macroscale strain-based models will be compared amongst themselves and to the MDsimulations, resulting in a new strain-based porosity model fit to nanoscale simulation results.