Modeling and experiments in plasticity

We focus on challenges in advancing the modeling of plastic ¯ow processes to incorporate distinct characteristics of various length scales within materials and structures. The motivation is twofold. First, the goal of tailoring the material microstructure to control plastic deformation and related failure processes is of great economic importance. Product development cycles have become so short that traditional empirical approaches to alloy modi®cation are noncompetitive in the global marketplace. Second, materials selection and design for durability, which rests upon our understanding of phenomena occurring at microstructural scales as well as at the scale of structural components, is of critical importance as we head into an era where an extensive infrastructure must be maintained. Cost constraints on new systems dictate much more quantitative design and analysis procedures than in the past. Research needs are discussed in a number of key areas involving experiments and modeling, including: experiments conducted at multiple length scales of resolution; principles for multiscale modeling and scale e€ects in plasticity; coupling of plasticity-induced damage with texture and phase transformations; progressive cyclic deformation and failure; microstructure-scale plasticity of cast alloys and low symmetry polycrystals; and employment of massively parallel computing to determine model parameters and forms of evolution equations for internal structure variables