A new thermodynamical model for solid metals under elastic deformations

PABLO OCHOA; DALIA BERTOLDI

CONTINUUM MECHANICS AND THERMODYNAMICS

SPRINGER

Lugar: Berlin; Año: 2019

0935-1175

We present a theoretical model of the free Helmholtz energy (F) for solid metals that incorporates three contributions: the elastic part through a local strain description, the vibrational energy within a quasi-harmonic Einstein model with volume-dependent cohesive energy, and the elec- tronic contribution in the free electron gas setting. To get F, we introduce discrete approximations of the Helmholtz energy defined in cubic lattices and show their convergence to F by finite element methods.For homogeneous deformations, the obtained model is applied to derive an equation of state (EOS) which shows a very good agreement with experimental data. Moreover, by comparing with other known theoretical EOSs, the present model is highly stable under different estimations of its parameters.