U.S-Czech Research on Computational Models in Phenomenological Plasticity, Planning Visit

Northern Arizona University, Flagstaff AZ

Investigators

Abstract

Through this planning visit U.S. researchers Heidi Feigenbaum of Northern Arizona University and Yannis Dafalias, from the University of California-Davis, will initiate an international cooperative research project with Czech partners to examine computational phenomenological plasticity. Their counterpart, Jiri Plesek, will head collaborative efforts at the Czech Academy of Sciences' Institute of Thermomechanics. Results from the planned long-term collaboration should improve our fundamental understanding of the mechanics of materials and, if successful, may lead to new models to improve predictions for practical engineering and materials problems, ranging from predicting ratcheting strains to elastic spring back during metal forming. The U.S. team's strengths in deformation and plasticity theory as well as directional distortion and simulation offer an excellent complement to those of the Czech partners in computation and theory. Specifically, Plesek's group will contribute the finite element platform with which the Feigenbaum-Dafalias models will be implemented. Together their goal is to refine plans for calculating model constants by using experimental results and analytical solutions to examine the fundamental modes of deformation, such as tensile tests and ratcheting. For better calibration, they intend to work toward implementing governing equations in the framework of a large deformation finite element computer code. This project planning visit fulfills the program objective of advancing our knowledge of the mechanics of materials by enabling researchers in the United States and Europe to share resources and expertise in areas of mutual interest and competence. This U.S.-Czech team intends to produce a simple, accurate metal plasticity model that addresses directional distortional hardening. Broader impacts may include the eventual ability to avoid failures in structures that are subject to cyclic plastic loading throughout their life-spans. Long-term success could mean future savings in cost and time, coupled with heightened safety through improved engineering applications.