Dr. Jianfeng (Jeff) Wang
City University of Hong Kong
Dr. Wang is currently an Associate Professor at the Department of Architecture and Civil Engineering at City University of Hong Kong. Dr. Wang is internationally renowned for his works within the field of X-ray micro-computed tomography (micro-CT) characterization and discrete element method (DEM) modeling of the micromechanics of granular soils. His research aims to explore the multiscale physics and mechanics underlying the macroscopic soil behavior. His works over the past two decades include the micro-CT characterization of micro-structures and micro-morphologies of geomaterials, and the DEM modeling and analysis of fundamental soil behaviors of crushable sands and their applications in various kinds of geotechnical engineering problems such as pile foundation, slope stability and retaining structures, etc. Dr. Wang's work has been awarded the prestigious international prizes including 2011 Geotechnical Research Medal (UK Institution of Civil Engineers) and 2010 Higher Education Institutions Outstanding Research Award - Natural Science Award (the Ministry of Education of China). He has delieved a number of keynote lectures in renowned international conferences and workshops. So far Dr. Wang has authored and co-authored over 130 peer-reviewed publications including 70 SCI journal papers and over 60 international conference papers.
Title: Recent progress on experimental characterization and numerical modeling of the micromechanics of sands
Abstract: This paper reviews the recent progress in nano-focus X-ray CT characterization of particle breakage behavior of sands and mathematical modeling of 3D morphology of sand particles. The novelty of the study stems from the pioneering application of the state-of-the-art synchrotron CT technology and mathematical methods to the exploration of the fracture behavior of sand particles at the micron and sub-micron scales, the accurate reconstruction and reassembling of 3D sand particle morphology, the assessment of the effects of particle microstructure and micro-morphology on the fracture behavior. The presentation first introduces the nano-focus X-ray CT technique and describes its application to the exploration of particle breakage behavior in typical element soil tests, e.g., single particle crushing test, oedometer test and triaxial test. Typical results from the CT study are presented. Then the spherical harmonic analysis (SHA) method, the image matching techniques and their application to the reconstruction and reassembling of 3D sand particle morphology are presented and discussed. Finally a sophisticated DEM modeling of a mini-triaxial test of a sand specimen which incorporates an accurate one-to-one mapping of sand particles is presented, showing an excellent agreement between the simulation and experimental results on both macro- and micro-scopic levels.