时   间: 2015-05-29 14:00:00 

 

　　地   点: 木兰船建大楼A1006 

 

　　主   办:  

 

　　联系人: 沈水龙 教授 

 

　　报告人介绍：

 

　　Anil Misra received his bachelor‘s degree in civil engineering from the Indian Institute of Technology, Kanpur, India, and his M.S. and Ph.D. degrees from the University of Massachusetts at Amherst.  He is currently a Professor in the Civil, Environmental and Architectural Engineering Department of the University of Kansas, Lawrence.  He also serves as Associate Director of the University of Kansas Bioengineering Research Center (KU-BERC).  Dr. Misra has a broad research interest that spans topics covering both basic and applied aspects of mechanics of geomaterials, interfaces and biomaterials, including analytical, computational and experimental granular micromechanics, particle and atomistic methods, multi-scale modeling, constitutive behavior, micro-macro correlations, and multi-modal material characterization using high resolution techniques.  He has co-edited three books; guest edited three journal special issues; and authored more than 200 papers in journals, edited books and conference proceedings.  He has made more than 100 presentations of his research results at national and international fora.  His research has been funded by a variety of sources, including the United States National Science Foundation, National Institute of Health, and private industry.  He is active in various professional societies and serves as reviewer and editorial board member of a number of journals. (webpage: http://people.ku.edu/~amisra/)

 

　　报告内容简介：

 

　　Granular micromechanics approaches have been used since 1980s to develop models for geomaterials.  These approaches are based upon a similar particulate view as the discrete element method (DEM); however they utilize homogenization methods to obtain continuum description of the granular geomaterials.  The resultant models offer the versatility of investigating the influence of both the macro-scale parameters and the grain-scale parameters on the overall stress-strain response by incorporating the effect of nearest neighbor grain interactions through the inter-granular force-displacement relationship and orientation vector.  The advantages are clear since (1) the computational needs are far smaller than that of other particulate approaches, such as DEM, (2) the models naturally exhibit macro-scale effects such as material density and inherent and loading-induced anisotropies, and (3) can readily represent micro-scale effects of particle interactions, including rate effects.  In their earlier formats, the models based upon granular micromechanics were successful in describing the small strain behavior.  In recent years, these models have undergone further refinement and have been successfully applied to model a number of phenomena exhibited by granular geomaterials.  In particular, the models have been shown to successfully describe the damage and softening in cementitious materials [1].  The approach also leads to a 2nd gradient continuum theory involving strain gradient and its conjugated double stresses useful for modeling shear bands [2].  The method has also been extended to include rate effects and the model predictions have shown both quantitative and qualitative consistency with the observed behavior for asphalts [3].  Recently, we have derived the continuum constitutive relationships using granular micromechanics approach from a thermomechanical basis [4,5].  Efficient numerical scheme for time-integration has also been investigated [6] and the model has been implemented into finite element formulation for predicting permanent deformation and damage in pavement structures.  In the proposed presentation, the recent developments of the granular micromechanics approach for rate-dependent damage will be described.