Theory of Plastic Flow versus Theory of Plastic Deformation

摘要

Typical theories of plastic flow and plastic deformation are discussed, and the concept of neutral change of stress is introduced. A neutral change of stress can be considered as a limiting case of either loading or unloading. It therefore seems reasonable to demand that the stress‐strain relations for both loading and unloading should predict the same change of strain when applied to a neutral change of stress. It is shown that this condition is satisfied by the theories of plastic flow but not by the theories of plastic deformation.