Back to Departmental Colloquium: Spring 2006
Departmental Colloquium
Date: Thursday, Mar 23, 2006
Time: 4:15PM
Location: JWB 335
John Willis
Cambridge
Title |
Scale effects induced by strain-gradient plasticity and interfacial resistance in heterogeneous media |
Abstract |
The theory and physical origin of strain-gradient plasticity will be briefly outlined, and a “deformation theory” (as opposed to “flow theory”) version will be developed. A distinctive aspect of the theory is that it requires an additional boundary condition, or condition across any interface. This may be turned to advantage by introducing an “interfacial potential” that penalises the development of plastic flow at an interface, by impeding the motion of dislocations. A scale-dependent hardening effect in any material such as a composite or a polycrystal is generated thereby. Treatment of such materials as having random microgeometry renders exact solution intractable but approximations (which in some cases are bounds) can be developed via a variational formulation. This will be illustrated with simple examples. |
Mathematical Biology
Data Science and Machine Learning