Elasto-plasticity

For almost any metal and at rather small rates of loading, we obtain a mean curve \(\sigma (\varepsilon )\) during a tensile experiment: this is a static curve. The whole static curve may be analysed with the help of several successive mathematical relations, which are models of the elastoplastic behaviour. The case of standard elastoplastic material is investigated and properties of evolution problem are analysed in this case. The local behaviour is defined by two potentials: one for defining the internal state of the body, and another one to described how the system can evolve with or without dissipation.