Thermodynamics-Based Models

The existing soil models based on the traditional elasto-plasticity framework do not consider the physical mechanism of strong couplings between elasticity and plasticity. These couplings are related to the thermodynamic processes of energy storage and dissipation, and their connection with the granular microstructure. The group, in collaboration with Dr Zhichao Chang of Chongqing University, develops  micromechanics-inspired fabric-dependent thermodynamic model to simulate the critical-state, phase transformation, multidirectional cyclic shearing and instability behavior of granular materials based on a double-entropy granular thermodynamic system: (a) thermal entropy produced by energy dissipations (i.e., heating production) and (b) granular entropy, which describes granular kinetic fluctuation.

Zhang, Z. and K. Soga, “Thermodynamic Constitutive Model for Sands with Consideration of Distributed Fabric,” Journal of Engineering Mechanics, 2021, Vol. 147(12)

Zhang, Z. and Soga, K., 2025. Micromechanics-Inspired Granular Thermodynamics: A Constitutive Model for Multidirectional Cyclic Shearing. Journal of the Mechanics and Physics of Solids, p.106170.