General Dynamics Professor of Aerospace Engineering
Texas A&M University
“Recent Advances in Modeling Porous Materials Plasticity”
Abstract: The talk discusses from first principles the plasticity of porous materials. Emphasis is laid on unhomogeneous yielding, defined as the process of yielding and plastic flow under gradient-free macroscopically nonuniform deformation. The nonuniformity is represented by strain localization in one or more bands of finite thickness. A universal feature of all intrinsic yield criteria is their dependence upon the band resolved normal and shear stresses. When specialized to isotropy, a Mohr–Coulomb and a Rankine–Tresca criteria emerge as two extremes. The general theory stands for a finite number of bands or yield systems. Its overall structure bears some features of crystal plasticity, but with dilatancy. The evolution of microstructural parameters can be given in general terms, being solely based on the kinematic constraints of unhomogeneous yielding and matrix incompressibility. Throughout the talk, the competition with homogeneous yielding, heretofore taken for granted, is analyzed with or without strain and strain-rate hardening effects. The thermodynamic consistency of this new class of constitutive relations and a link to strain-gradient theories will be discussed along with potential applications.
BIO: Amine Benzerga is currently the General Dynamics Professor of Aerospace Engineering at Texas A&M University, which he joined in 2004. He holds the Diploma of Ingenieur in Aerospace Engineering from SUP’AERO (Toulouse, class of 1995), a M.S. in Mechanical Engineering from Paul Sabatier University in the same year and a Ph.D. in Materials Science and Engineering from Ecole des Mines de Paris in 2000. Prior to his joining Texas A&M, he was a Research Engineer at the National Research Laboratory of Gaz de France (now NG, Paris, France) on leave at Brown University (Providence, USA) where he later pursued his post-doctoral studies in Solid Mechanics. His research interests include the deformation and fracture of structural and functional materials. Dr. Benzerga was the recipient of a CAREER award from NSF in 2008 and the Edward Pete Aldridge Associate Professor of Aerospace Engineering (2011-2014). He is currently the Director of the Center for intelligent Multifunctional Materials and Structures (CiMMS) and holds a joint appointment in the Department of Materials Science and Engineering.