Seminars and visits at the University of Hong Kong and Hong Kong University of Science and Technology
Thank you Professors Jidong Zhao and Jinhyun Choo for hosting me at HKU and HKUST. It's a great visit.
Computational thermomechanics of crystalline rock. Part I: a combined multi-phase-field/crystal plasticity approach for single crystal simulations
SeonHong Na, WaiChing Sun
Abstract: Rock salt is one of the major materials used for nuclear waste geological disposal. The desired characteristics of rock salt, i.e., high thermal conductivity, low permeability, and self-healing are highly related to its crystalline microstructure. Conventionally, this microstructural effect is often incorporated phenomenologically in macroscopic damage models. Nevertheless, the thermomechanical behavior of a crystalline material is dictated by the nature of crystal lattice and micromechanics (i.e., the slip-system). This paper presents a model proposed to examine these fundamental mechanisms at the grain scale level. We employ a crystal plasticity framework in which single-crystal halite is modeled as a face-centered cubic (FCC) structure with the secondary atoms in its octahedral holes, where a pair of Na+ and Cl− ions forms the bond basis. Utilizing the crystal plasticity framework, we capture the existence of an elastic region in the stress space and the sequence of slip system activation of single-crystal halite under different temperature ranges. To capture the anisotropic nature of the intragranular fracture, we couple a crystal plasticity model with a multi-phase-field simulation that does not require high-order terms for the phase field. Numerical examples demonstrate that the proposed model is able to capture the anisotropy of inelastic and damage behavior under various loading rates and temperature conditions. [PDF]
Abstract ID and Title: 290275: Computational thermo-hydro-mechanics for freezing and thawing multiphase geological media in the finite deformation range
Final Abstract Number: MR33C-0478*
Presentation Type: Poster
Session Date and Time: Wednesday, 13 December 2017; 13:40 - 18:00
Session Number and Title: MR33C: Multiphysics Models of Coupled Processes in Rock Mass Posters
News about Computational Poromechanics lab at Columbia University.