Seminar - Elastoplastic Damage Micromechanics for Continuous Fiber Reinforced Ductile Matrix Composites with Progressive Fiber Breakage by Professor J. Woody Ju
日期：2017 年 05 月 31 日 ( 星期三)
Time：3:00 pm – 4:00 pm
An elastoplastic damage micromechanical framework considering evolutionary fiber breakage is proposed to predict the overall material behaviors of continuous fiber-reinforced composites with ductile matrix under external loading. The overall nonlinear behavior of a composite is primarily attributed to the plastic defor-mation in the matrix as well as the damage evolution due to fiber breakage. The effective elastoplastic de-formations are governed by means of the effective yield surface derived from a representative microstructure with elastic fibers embedded in an elastoplastic matrix material. The matrix behaves elastically or plastically depending on the local stress, and the effective elastoplastic deformation obeys the associative plastic flow rule and isotropic hardening law. In addition, taking advantage of the eigenstrain due to fiber breakage pro-posed by Ju and Wu (2016) together with a Weibull statistic model, the evolutionary fiber breakage mecha-nism is effectively predicted. Finally, the overall elastoplastic stress-strain responses are reached under the framework of micromechanics and damage mechanics. Comparisons between the proposed theoretical pre-dictions and experimental data are performed to illustrate the capability of the proposed framework.
Professor Ju received his M.S. and Ph.D. from UC Berkeley. He is a senior Professor at UCLA, and served as Department Chair of Civil and Environmental Engineering. 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-in-Chief of the Intl. Journal of Damage Mechanics, an Associate Editor of the ASCE J. of Nanomechanics and Micromechanics, and an Editorial Board member of the Acta Mechanica. Prof. Ju received the 1991 Presidential Young Investigator Award from NSF and White House, 1991 Alfred Rheinstein Faculty Award from Princeton Univ., 1997 ASCE Walter Huber Civil Engineering Research Award, 1998 ASME Fellow Award, 2000 ACI-James-Instruments Award in NDE, 2006 ASCE Fellow Award, 2007 USACM Fellow Award, 2008 ACI Fellow Award, 2008-2009 Invited Chair Professor from University of Paris VI and ENS Cachan (France), 2008 Publication Award of Merit from the Structural Engineers Association, 2009-2012 Chang-Jiang Scholar Chair Professor (Ministry of Education, Guangxi University), 2010 IACM Fellow Award, 2010 Kwang-Hua Chair Professor (Tongji University), 2011-2013 Tongji Univ. Chair Professor, National 1000 Talents Program (Short-Term) Distinguished Chair Professor (2013-2018), Tongji University Distinguished Chair Professor (2013-2018), Guangxi University Distinguished Chair Professor (2013-2021), and 2013 ICACM Award, and Honorary Distinguished University Professor from Southwest Jiaotong University (2015-now), etc. Prof. Ju’s publications have been highly cited by the ISI Web of Science (SCI).