To the question about criteria of plasticity and strength of metals
- 1 — Ph.D.
- 2 — Ph.D.
Abstract
The mathematical theory of plasticity is based on the law of the existence of a generalized function of the mechanical state of a material at constant temperature and strain rate. The essence of this law is reduced to the recognition for each material of a generalized, independent of the type of stress state, curve of plastic flow in certain coordinates. The conditions of plasticity and strength theory express this law by various equations characterizing the hardening of the material during its plastic deformation.The influence of normal stresses on the resistance of a material to deformation is quite obvious, since normal stresses in shear planes cause frictional forces that facilitate or impede the plastic flow of the material. In order to at least approximate the strength of a material under a complex stress state, it is necessary to perform at least two comparative tests for two types of stress states: tension-compression, tension-torsion or, in extreme cases, tension-cutting. The initial tests should be as simple and reliable as possible.
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