Mechanics of solid bodies in the plastically-deformable state

Up to now, the mechanics of continua that are endowed wi th the general notion of stress that was created by Cauchy has been almost exclus ively applied to fluid and solid elastic bodies. Saint-Venant ( ) has outlined a theory for the domain of plastic or permanent changes of form that, however, does not yield the required number of equations for the determination of the motion. Other oc casional attempts in this direction have not arrived at any conclusion, either ( ). The following discussion leads to a complete Ansatz f or the equations of motion for plastically-deformable bodies in the context of Cauchy’s mechanics and is connected with certain facts of experience that characterize t he domain of application.