Abstract: In ductile fracture of structural alloys, damage initiates at brittle secondary phases and proceeds by void growth to coalescence. The lecture will begin by an account of microscopic damage mechanisms highlighting the role of microstructure and its evolution on macroscopic fracture properties. Within a top-down approach, the modeling framework relies on rate-dependent constitutive descriptions that account for plastic anisotropy, micro-scale localization, non-proportional loading paths, along with the volume fraction, shape, relative spacing and orientation of voids. One peculiar feature of this framework is that crack initiation and growth are natural outcomes to competing plastic or viscoplastic mechanisms. A mathematical model coupling plastic anisotropy with damage will be corroborated based on a rigorous micromechanical treatment, validated by finite element simulations of voided cells for representative materials. The lecture will demonstrate the promising capabilities of the approach at not only predicting global fracture properties in structural steel but also key microstructural variables at well-identified stages of the fracture process in well-controlled experiments.
Bio: A. Amine Benzerga is currently the Edward "Pete" Aldridge Career Development Associate Professor I in the Department of Aerospace Engineering at Texas A&M University, which he joined in January 2004. He holds the Diploma of Ingenieur from the French leading Aerospace Engineering school 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 (France) in 2000. Prior to his joining Texas A&M, he was a Research Engineer at the National Research Laboratory of Gaz de France (Paris, France) on leave at Brown University (Providence, USA), where he later pursued his post-doctoral studies in Solid Mechanics. His current research interests include micro-mechanics of discrete dislocation plasticity, fracture in structural metallic materials and macromolecular mechanics of amorphous polymers.
Host: Prof. G. Robert Odette