Defense Tech Briefs - Multiscale Virtual Design and Testing of Materials

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Multiscale Virtual Design and Testing of Materials

Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio
Jul 31 2007
Page 3 of 3 Advertisement: A continuum model of cracking by chemical embrittlement. The results of the abovementioned research on decohesion were used to develop a continuum model for simulation of stress corrosion cracking in steels. An integral part of this development was the renormalization of the decohesion as modelled by first principles, occurring at a length scales of the order of an Angstrom, into an effective cohesion law at a length scale suitable for efficient continuum modeling. The model also includes the stress-dependent diffusion of chemical species (e.g. hydrogen) through the material in the presence of the non-uniform crack-tip field. The model predicts a number of features of crack growth that are observed in experiments. The first basic discrete/continuum model for non-steady flow of diffusing chemical species. This is a multiscale diffusion model in which one region of material is treated by use of the full discreteness of the diffusing entities while another, much larger region is treated by use of the continuum diffusion equation. By making the discrete-submodel region small, considerable time is saved in computations, making it possible to perform much longer simulations with no loss in accuracy. This work was done by W.A. Curtin and A. Needleman of Brown University; M. Ortiz and R. Phillips of California Institute of Technology; E. Kaxiras of Harvard University; G. Cedar of Massachusetts Institute of Technology; E. Carter of the University of California, Los Angeles; R. Miller of Carleton University; C. Woodward of Northwestern University; and D. Farkas of Virginia Polytechnic Institute and State University for the Air Force Research Laboratory. For more information, download the Technical Support Package (free white paper) at www.defensetechbriefs.com/tsp under the Information Sciences category. AFRL-0037 This Brief includes a Technical Support Package (TSP). *Multiscale Virtual Design and Testing of Materials* (reference AFRL-0037) is currently available for download from the TSP library. Login first to download. Username Password Remember me Lost Password? Register Prev: Shape-Based Recognition of 3D Objects in 2D Images. Next: Advances in Algorithms for CFD and Finite-Element Simulation. << Start < Prev 1 2 3 Next > End >>

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