University of Minnesota
Aerospace Engineering and Mechanics
Spring 2001 Seminar Series



A gradient theory of single-crystal plasticity that accounts for geometrically necessary dislocations


Prof. Mort Gurtin

Mathematical Sciences Department, Carnegie Mellon University


Abstract


This talk will discuss the kinematics of of geometrically necessary dislocations (GNDs) in finite plasticity and will develop a gradient theory that accounts for GNDs within a thermomechanical framework. The theory is based on classical macroforces; microforces for each slip system consistent with a microforce balance; a mechanical version of the second law that includes, via the microforces, work performed during slip; a rate-dependent constitutive theory that includes dependences on a tensorial measure of geometrically necessary dislocations. The microforce balances are equivalent to nonlocal (pde) yield conditions for the individual slip systems. To make contact with classical dislocation theory, the microstresses are shown to represent counterparts of the Peach-Koehler force on a single dislocation.

Friday, May 4, 2001
209 Akerman Hall
2:30-3:30 p.m.


Refreshments served after the seminar in 227 Akerman Hall.
Disability accomodations provided upon request.
Contact Kristal Belisle, Senior Secretary, 625-8000.