Based on the endochronic theory, a viscoelastic model is developed, in which the intrinsic time is defined as a function of real time. By defining hardening functions, the creep and relaxation equations are derived directly from the differential constitutive equation and are then used to simulate the mechanical properties of pure polycrystalline magnesium. It is proved that the proposed viscoelastic model is very useful for analysing creep and relaxation problems.
da Costa AndradeE. N.Proc. R. Soc., 1910, 84A, 1–12.
2.
WyattO. H.Proc. Phys. Soc., 1953, 66B, 459–475.
3.
PomeroyC. D.Creep of Engineering Materials, 1978 (Mechanical Engineering Publications, London).
4.
EvansR. W.WilshireB.Creep of Metals and Alloys, 1985 (The Institute of Metals, London).
5.
FinnieI.HellerE.Creep of Engineering Materials, 1966 (McGraw-Hill, London).
6.
ValanisK. C.A theory of viscoplasticity without a yield surface, Part I: General theory. Arch. Mech., 1970, 23, 517–534.
7.
ValanisK. C.A theory of viscoplasticity without a yield surface, Part II: Application to the mechanical behavior of metals. Arch. Mech., 1971, 23, 535–557.
8.
WuH. C.YipM. C.Strain rate and strain rate history effects on the dynamic behavior of metallic materials. Int. J. of Solid Struct., 1980, 16, 515–536.
9.
HoC. C.WuH. C.An investigation of transient creep by means of endochronic viscoplasticity and experiment. Trans. ASME, J. Engng Mater, and Technol., 1992, 117, 260–268.
10.
WuH. C.YipM. C.Endochronic description of cyclic hardening behavior for metallic material. Trans. ASME, J. Engng Mater. and Technol, 1981, 103, 212–217.
11.
ValanisK. C.LeeC. F.Endochronic theory of cyclic plasticity with applications. J. Appl. Mech., 1984, 51, 367–374.
12.
ValanisK. C.Recent application of the endochronic theory: A temperature and strain rate shift principle in aluminum. Report G378-CHME-74–003, University of Iowa, 1974.
13.
ShiL.NorthwoodD. O.Strain-hardening and recovery during the creep of pure polycrystalline magnesium. Acta Metall. Mater., 1994, 42 (3), 871–877.
