Course on Theory of Plasticity

Plasticity describes the deformation of a material undergoing non-reversible changes of shape in response to applied forces.The key fundamental mechanism of metal plasticity is movement of atoms along atomic slip planes.Plasticity in a crystal of pure metal is primarily caused by two modes of deformation in the crystal lattice: slip and twinning. Slip is a shear deformation which moves the atoms through many interatomic distances relative to their initial positions.The theory of plasticity is the branch of mechanics that deals with the calculation of stresses and strains in a deformable body in which a material will not fail when subjected to the action of a force,but will not recover completely so that a permanent deformation results when the applied forces are removed.Thus theory of plasticity describe the plastic behaviour of materials.