光华同济大学土木工程学院基金——光华讲座教授讲座之四
Kwang-Hua Chair Professor Lecture No. 4

题 目：Hybrid Coupled Elastoplastic Damage and Healing Models For Geomaterials During Earth Moving Processes 主讲人：Professor J. Woody Ju, Ph.D., P.E. Department of Civil and Environmental Engineering University of California, Los Angeles, CA 90095, USA Time: 13:30 p.m. Friday, July 2, 2010 Address: Room 201, Department of Geotechnical Engineering, Tongji University(岩土楼201)

Abstract
Innovative energy-based hybrid coupled elastoplastic damage and healing models for geomaterials are presented for earth moving processes and numerical simulations. A class of coupled elastoplastic constitutive damage-healing models, based on the continuum thermodynamic framework, is proposed within a strain-energy based formulation. In particular, the governing damage and healing evolutions are coupled and characterized through the effective (true) stress concept in conjunction with the hypothesis of strain equivalence. By incorporating a micromechanics-motivated brittle (tensile) damage characterization and a ductile (mixed tension-compression) damage-healing characterization, the new isotropic and anisotropic models and efficient computational algorithms have been implemented to represent different granular materials. Novel computational algorithms are systematically developed based on the two-step operator splitting methodology. Further, the elastic-damage-healing predictor and the plastic corrector are incorporated into the RKPM meshfree codes to capture damage and strain localization. Several numerical examples are presented to illustrate the salient features of the proposed models.

Biographical Sketch: Prof. Ju received his Ph.D. (1986) from UC Berkeley. He is the Chair of Structural Engineering & Mechanics Program at UCLA, and served as the Department Chair. Prof. Ju served as an Associate Editor for ASME Journal of Engineering Materials & Technology, and for ASME Journal of Applied Mechanics from 1995 to 2002. He is the Editor of Intl. Journal of Damage Mechanics (2008 JCR Impact Factor 1.97), an Associate Editor of ASCE J. of Nanomechanics and Micromechanics, and an Editorial Board member of Acta Mechanica. Prof. Ju received the 1991 Presidential Young Investigator Award from the NSF and White House, 1991 Alfred Rheinstein Faculty Award from Princeton University, 1997 ASCE Walter Huber Civil Engineering Research Award, 1998 ASME Fellow Election, 2000 ACI-James-Instruments Award in NDE, 2006 ASCE Fellow Election, 2007 USACM Fellow Award, 2008 ACI Fellow Award, 2008-2009 Invited Chair Professorship from the University of Paris VI and ENS Cachan (France), 2008 Publication Award of Merit from the Structural Engineers Association, 2009 Chang-Jiang Scholar Chair Professor (MOE, China), 2010 IACM Fellow Award, and 2010 Kwang-Hua Chair Professor (Tongji Univ.), etc. Prof. Ju’s publications have been highly cited by the ISI Web of Science. His research interests encompass structural engineering, structural mechanics, computational mechanics, damage & fracture mechanics, micromechanics & nanomechanics of composites, multiscale material modeling, finite elements, biomechanics, geomechanics, service life predictions, and durability of cementitious composites.