Editing Plasticity (physics) (section)

=== Flow plasticity theory ===
{{main|Flow plasticity theory}}
In 1934, [[Egon Orowan]], [[Michael Polanyi]] and [[Geoffrey Ingram Taylor]], roughly simultaneously, realized that the plastic deformation of ductile materials could be explained in terms of the theory of [[dislocations]].  The mathematical theory of plasticity, [[flow plasticity theory]], uses a set of non-linear, non-integrable equations to describe the set of changes on strain and stress with respect to a previous state and a small increase of deformation.