Our paper "A stabilized finite element formulation for monolithic thermo-hydro-mechanical simulations at finite strain" published in IJNME at 2015 is the top 5 most cited papers from 2015 to 2016. The paper can be downloaded via the Wiley Online Library [URL].
International Symposium on Multiscale Computational Analysis of Complex Materials, 29-31.August 2017, Denmark
Dates and Location: August 29-31, Copenhagen/Lyngby, Denmark
Overview and Objectives:
Complex materials play an essential role in many applications, ranging from turbine blades, car chassis, computer and cell phone cases, battery systems, stretchable and wearable electronics, to biomedical applications. Those materials often operate and must maintain their high performance in harsh environments. The advancement of computationalmethods at multiple scales opens new possibilities for the design of such complex materials and the optimization of their intrinsic properties under extreme events. The bridging of different length and time scales though still represents an area of active research with many unresolved challenges. For example, material degradation is considered as a typical multiscale process, controlled by nanoscale defects, highly affecting the macroscopic material response.
The confirmed presenters include Jose E. Andrade (Caltech), Ronaldo I. Borja (Stanford), JS Chen (UC San Diego), William Curtin (EPFL), Jacob Fish (Columbia), Somnath Ghosh (Johns Hopkins), Ellen Kuhl (Stanford), Lars P. Mikkelsen (TU Denmark ), Christian Frithiof Niordson (TU Denmark), Stefanie Reese (RWTH Aachen), Siegfried Schmauder (Stuttgart), Jörg Schröder (Universität Duisburg-Essen), Mads Peter Sørensen (TU Denmark) and others.
Symposium Topics include but are not limited to • Multiscale modeling of materials • Multiphysics modeling of materials • Computational materials science • Micromechanics of materials • Scale bridging and homogenization • Materials under extreme environments • Hierarchical materials • Nanomaterials • Biological and natural materials • Geomaterials
Computational thermo-hydro-mechanics for multiphase freezing and thawing porous media in the finite deformation range
SeonHong Na, WaiChing Sun
A stabilized thermo-hydro-mechanical (THM) finite element model is introduced to investigate the freeze-thaw action of frozen porous media in the finite deformation range. By applying mixture theory, frozen soil is idealized as a composite consisting of three phases, i.e., solid grain, unfrozen water and ice crystal. A generalized hardening rule at finite strain is adopted to replicate how the elasto-plastic responses and critical state evolve under the influence of phase transitions and heat transfer. The enhanced particle interlocking and ice strengthening during the freezing processes and the thawing-induced consolidation at the geometrical nonlinear regimes are both replicated in numerical examples. The numerical issues due to lack of two-fold inf-sup condition and ill-conditioning of the system of equations are addressed. Numerical examples for engineering applications at cold region are analyzed via the proposed model to predict the impacts of changing climate on infrastructure at cold regions. [DRAFT]
A unified variational eigen-erosion framework for interacting brittle fractures and compaction bands in fluid-infiltrating porous media
Kun, Wang WaiChing Sun
The onset and propagation of the cracks and compaction bands, and the interactions between them in the host matrix, are important for numerous engineering applications, such as hydraulic fracture and CO2 storage. While crack may become flow conduit that leads to leakage, formation of compaction band often accompanies significant porosity reduction that prevents fluid to flow through. The objective of this paper is to present a new unified framework that predicts both the onset, propagation and interactions among cracks and compaction bands via an eigen-deformation approach. By extending the generalized Griffith's theory, we formulate a unified nonlocal scheme that is capable to predict the fluid-driven fracture and compression-driven anti-crack growth while incorporating the cubic law to replicate the induced anisotropic permeability changes triggered by crack and anti-crack growth. A set of numerical experiments are used to demonstrate the robustness and efficiency of the proposed model. [DRAFT]
Presentations at AGU Fall Meeting from our research group (Poster Session + Oral Presentation, Moscone South, Friday)
H51C-1492 Phase field modeling of crack propagations in fluid-saturated porous media with anisotropic surface energy
SeonHong Na1, WaiChing Sun1, Hongkyu Yoon2 and Jinhyun Choo3, (1)Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, United States, (2)Sandia National Lab, Albuquerque, NM, United States, (3)Stanford University, Stanford, CA, United States
- Poster Hall
H51C-1490 A discontinuous finite element approach to cracking in coupled poro-elastic fluid flow models
Cian R Wilson1, Marc W Spiegelman1, Owen Evans1, Ole Ivar Ulven2 and WaiChing Sun3, (1)Columbia University of New York, Palisades, NY, United States, (2)University of Oslo, Oslo, Norway, (3)Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, United States
- Poster Hall
H51C-1474 A unified variational eigen-deformation model for simulating compaction band and fracture propagation in fluid-infiltrating porous media
WaiChing Sun and Kun Wang, Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, United States
- Poster Hall
H54C-05 Fluid-induced Rock Transformation Modeled via a Two-way Coupled Hydromechanical DEM-network Model
Ole Ivar Ulven, University of Oslo, Oslo, Norway and WaiChing Sun, Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, United States
FRIDAY, 16 DECEMBER 2016
08:00 - 12:20
13:40 - 15:40
16:00 - 18:00
17:00 - 17:15
Our manuscript (co-authored by former student Zhijun Cai and postdoc scholar Dr. Jinhyun Choo) has been accepted by International Journal of Numerical Method in Engineering (see PDF). The abstract is listed below:
Mixed Arlequin method for multiscale poromechanics problems
An Arlequin poromechanics model is introduced to simulate the hydro-mechanical coupling effects of fluid-infiltrated porous media across different spatial scales within a concurrent computational framework. A two-field poromechanics problem is first recast as the two-fold saddle point of an incremental energy functional. We then introduce Lagrange multipliers and compatibility energy functionals to enforce the weak compatibility of hydro-mechanical responses in the overlapped domain. To examine the numerical stability of this hydro-mechanical Arlequin model, we derive a necessary condition for stability, the two-fold inf--sup condition for multi-field problems, and establish a modified inf--sup test formulated in the product space of the solution field. We verify the implementation of the Arlequin poromechanics model through benchmark problems covering the entire range of drainage conditions. Through these numerical examples, we demonstrate the performance, robustness, and numerical stability of the Arlequin poromechanics model.
A special issue on computational poromechanics edited by Dr. Sun has been published in International Journal for Multiscale Computational Engineering. Detailed information can be found at
The table of content is listed below.
Table of Contents:
PREFACE: COMPUTATIONAL POROMECHANICS
GENERAL FORMULATION OF A POROMECHANICAL COHESIVE SURFACE ELEMENT WITH ELASTOPLASTICITY FOR MODELING INTERFACES IN FLUID-SATURATED GEOMATERIALS
Richard A. Regueiro, Zheng Duan, Wei Wang, John D. Sweetser, Erik W. Jensen
SIMULATING FRAGMENTATION AND FLUID-INDUCED FRACTURE IN DISORDERED MEDIA USING RANDOM FINITE-ELEMENT MESHES
Joseph E. Bishop, Mario J. Martinez, Pania Newell
MULTISCALE MODEL FOR DAMAGE-FLUID FLOW IN FRACTURED POROUS MEDIA
Richard Wan, Mahdad Eghbalian
IDENTIFYING MATERIAL PARAMETERS FOR A MICRO-POLAR PLASTICITY MODEL VIA X-RAY MICRO-COMPUTED TOMOGRAPHIC (CT) IMAGES: LESSONS LEARNED FROM THE CURVE-FITTING EXERCISES
Kun Wang, WaiChing Sun, Simon Salager, SeonHong Na, Ghonwa Khaddour
ALBANY: USING COMPONENT-BASED DESIGN TO DEVELOP A FLEXIBLE, GENERIC MULTIPHYSICS ANALYSIS CODE
Andrew G. Salinger, Roscoe A. Bartlett, Andrew M. Bradley, Qiushi Chen, Irina P. Demeshko, Xujiao Gao, Glen A. Hansen, Alejandro Mota, Richard P. Muller, Erik Nielsen, Jakob T. Ostien, Roger P. Pawlowski, Mauro Perego, Eric T. Phipps, WaiChing Sun, Irina K. Tezaur
Data-driven multiscale poromechanics model for cold region applications
WaiChing Sun, Columbia University
The hydro-mechanical responses of geological materials, such as soil and rock are strongly influenced by the environmental they subjected to. In cold region, the ice crystals in the void space may introduce many interesting multi-physical behaviors, such as creeping, thermal-induced hardening/softening and freeze-thaw action responsible for sharing the earth surface features and the mobility of vehicles. This talk focuses on the multiscale modeling techniques for predicting those thermos-hydro-mechanical behaviors developed by my research team and supported by the ARO Earth Materials and Process program. In particular, we will discuss (1) a finite strain finite element model that captures the freeze-thaw action of frozen soil, (2) multiscale techniques used to link grain-scale simulations to macroscopic micro-polar continua models, and (3) a new class of constitutive-law-free model that enables predictions made directly from experimental or simulated data based on spectral decomposition. Spurious pathological predictions by previous DEM-FEM models are examined and the remedies are proposed. Preliminary validation with experiments for the temperature- and rate-dependent behavior of frozen soil will also be discussed.
WaiChing Sun is an assistant professor in the Department of Civil Engineering and Engineering Mechanics at Columbia University, New York. From 2011 to 2013, he served as a senior member of technical staff at Sandia National Laboratories. Professor Sun works in the fields of theoretical and computational poromechanics with a special emphasis on geomechanical applications. His research includes multiscale modeling porous media, multiscale verification and validation with CT images, digital rock and granular physics, applications of mathematical tools, such as graph theory, Lie algebra for modern engineering problems. He has published more than 40 peer-reviewed articles. He received the Dresden Fellowship in 2016, US AFOSR Young Investigator Program Award in 2016, US Army Young Investigator Program Award in 2015, and the Caterpillar Best Paper Prize in 2013. Dr. Sun holds BS degree from UC Davis (2005), MS degrees from Stanford (2007) and Princeton (2008) and PhD degrees from Northwestern (2011).
Our proposal titled "Modeling the High-rate Responses of Wetted Granular Materials Across Scales and the Third-party Replicable Validation Exercises Utilizing 3D Printers" is selected to receive the 2017 AFOSR Young Investigator Award. The YIP is open to scientists and engineers at research institutions across the United States who received Ph.D. or equivalent degrees in the last five years and who show exceptional ability and promise for conducting basic research.The objective of this program is to foster creative basic research in science and engineering, enhance early career development of outstanding young investigators, and increase opportunities for the young investigators to recognize the Air Force mission and the related challenges in science and engineering.
The press release can be found in the URL below:
We will have two oral-presentations for the upcoming SES Meeting at University of Maryland:
Presentation 1: D8-4: Computational Mechanics of Materials and Structures: Room 0102 10:00am to 10:20am
Computational thermo-hydro-mechanics for multiphase frozen soil with unfrozen water flow in the finite deformation range -- SeonHong Na & WaiChing Sun
Presentation 2: D9-6 Friction, Fracture and damage: Room 0101 1:20pm-1:40pm
A binary eigen-deformation model for propagating fractures and shear failure in fluid-infiltrating porous media -- Kun Wang & WaiChing Sun
News about Computational Poromechanics lab at Columbia University.