The mechanical behavior of granular materials (sands and other cohesionless soils) is different in key aspects from other civil engineering materials like clay, steel, and concrete. The behavior is dominated by the particulate nature of the material. To better understand and model the materials correctly, we have to investigate the micromechanics, the behavior of granular materials at particle level. The numerical method, discrete element method has shown promising results and models the particles directly. With the rapid increase in computer power, we are able to study the interaction between particles and the change of packing of a large specimen size with complicate shapes of particles. In this seminar, the speaker will present the micromechanics of granular materials, very recent results of simulations of specimens with ellipsoids, and new discovery of the behavior of granular materials.

Speaker

Professor Ng, a Fellow of the American Society of Civil Engineers, was awarded the B.S. degree by National Taiwan University, the M.S. degree by Carnegie Mellon University, and the Ph.D. degree by Rensselaer Polytechnic Institute. He has been a civil engineer with the United Geotechnical Corp, Taiwan. Dr. Ng is currently the Full Professor in the Department of Civil Engineering, University of New Mexico since 1990. Dr. Ng has also served as a Senior Research Scientist at the United States Air Force Research Laboratory. His research interests are in micromechanics of granular materials, computational mechanics, and dynamics.