Research Theme
Our research objective is to develop theoretical and computational models that lead to more accurate predictions for energy and environmental geotechnics applications. As a multidisciplinary research team, we aim to bridge the traditional gaps between different science and engineering disciplines to better understand the multi-physical behavior of multi-phase materials and systems across different spatial and temporal scales. The subsections below summarize our previous and/or current work conducted by the group.
Data-driven Discovery of Interpretable Constitutive Models
Although a data-driven approach has enjoyed success in various fields, its lack of interpretability often hampers its trustworthiness and therefore prevents its application in real engineering practice. This work aims to propose a new machine learning framework that not only yields an interpretable model but also does not necessarily compromise predictive accuracy. Furthermore, we aim to develop an interpretable model that is inherently portable so that it can easily be incorporated into a continuum-scale model as a constitutive law that may yield results similar to those from a hierarchical multi-scale model while bypassing the need of running sub-scale simulations at individual Gauss points.
Microporomechanics of Energy Geosystems
A major drawback of the classical approach for simulating coupled processes in porous media is that it relies on an assumption that the solid and fluid constituents instantly reach a local thermal equilibrium, which may hinder the accurate prediction of the short-term behavior of the target media. This work aims to present a framework that adopts a dual-temperature concept that can consider the heat exchange between different constituents while coupling Stokes or Navier-Stokes flow inside fractures and macro-pores and Darcy's flow in a porous matrix.
Computational Modeling of Ice Lenses in Frozen Porous Media
Goal of this work is to present a computational framework that can overcome the limitations of the phenomenological model for frozen porous media. The formation of ice lens has oftentimes been explained in a one-dimensional setting that lacks the detailed coupling mechanism between elastoplastic response of the solid skeleton and the phase transition of the pore fluid. We aim to fill the knowledge gap by capturing the evolving interface of the ice phase constituent via Allen-Cahn type phase field model coupled with a classical thermo-hydro-mechanical model.
Multi-scale Modeling of Unsaturated Geomaterials
A statistical representative volume composed of thousands of fluid channels and particles may be very different than the field scale domain where billions of grain contacts and pores are collectively reacting to granular responses. This scaling effect is a big challenge in applying insights obtained from nano- or micro-scale laboratory tests to improve predictive capability in the field where applications require predictions at the meter or kilometer scales. The goal of this study is to present a multi-scale model that can preserve the physical insights and length scales without exhausting computational resources.
