On criteria for 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 reduces to recognizing for each material 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‑shear. The initial tests should be as simple and reliable as possible.
None
References
- Ratner S.I. To a question about the problems of plasticity theory. Izvestiya AN SSSR, OTN, 1950, vol. 3. (in Russian)
- Siebel and Meyer A. Zs. VDI. 77, 1345, 1933.
- Ratner S.I. Changes in the mechanical properties of metals under hydrostatic pressure. Zhurnal tekhnicheskoy fiziki, 1949, vol. 3. (in Russian)
- Tarasenko I.I. About physical bases of deformation and destruction of metals. Zapiski Gornogo Instituta, vol. XXIX, issue 3, 1954. (in Russian)
- Davidenkov N.N. How to Determine the Yield Strength at Torsion. Zavodskaya Laboratoriya, 1948, No. 10. (in Russian)
- Nadai A. Plasticity. ONTI, 1936. (in Russian)
- Ratner S.I. Strength and plasticity of metals, 1949, p. 21. (in Russian)
- Ratner S.I. Comparison of the mechanical properties of steel V7 under tension, torsion and compression. Zavodskaya Laboratoriya, 1946, No. 12. (in Russian)
- Fridman Ya.B. Deformation and fracture of metals under static and dynamic loads, 1946, p. 57. (in Russian)