Thermo-mechanical Behavior of Confined Granular Systems

We present a mathematical formulation that integrates thermal contact and Hertzian deformation models to understand the thermo-mechanical behavior of consolidated granular systems. The model assumes quasi-static equilibrium and quasi-steady heat conduction conditions that are appropriate for many thermally-assisted manufacturing processes. We perform a parametric study that explores the effect of applied thermal and mechanical loads, and of particles’ thermal expansion. The nonlinearity of the multi-physics problem reveals that thermo-mechanical coupling enhances the effective thermal conductivity and mechanical stiffness by directly impacting the interrelation between contact conductance and overlapping between the particles. Alterations in temperature profiles and displacements of particles are significant for materials with higher thermal expansion coefficients. In this regards, it is worth noting that the results of the proposed thermo-mechanical model depart from those of conventional compaction models based on a continuum mechanics description.