Modeling of Recovery of State Using the Viscoplasticity Theory Based on Overstress

  • E. Krempl
  • P. S. Majors
Conference paper
Part of the International Union of Theoretical and Applied Mechanics book series (IUTAM)


Unified constitutive models, which do not postulate separate constitutive equations for creep and plasticity but consider all inelastic deformation rate dependent, have been applied to the modeling of transient and cyclic short—term deformation behavior. Their application to modeling long—term creep has been demonstrated in principle and hinges on the introduction of recovery terms in the growth laws for the state variables. After postulating a set of phenomenological indicators of recovery the viscoplasticity theory based on overstress (VBO) for small strain is introduced and the growth law for each of two state variables is augmented by a recovery term. Hypothetical, but realistic material properties are postulated and numerical experiments are performed to simulate the tests which were previously designated as indicators of significant recovery. The results show that each state variable has specific effects and that recovery terms in both state variables are needed to reproduce the significant phenomena.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Pineau, A.: Personal communication, September 1990.Google Scholar
  2. 2.
    Krempl, E., McMahon, J.J., Yao, D.: Viscoplasticity based on overstress with a differential growth law for the equilibrium stress. Mechanics of Materials 5 (1986) 35–48.CrossRefGoogle Scholar
  3. 3.
    Yao, D., Krempl, E.: Viscoplasticity theory based on overstress. The prediction of monotonic and cyclic proportional and nonproportional loading paths of an Aluminum alloy. Int. J. of Plasticity 1 (1985) 259–274.CrossRefGoogle Scholar
  4. 4.
    Lee, K.D., Krempl, E.: An orthotropic theory of viscoplasticity based on overstress for thermomechanical deformations, in press Int. J. of Solids and Structures.Google Scholar
  5. 5.
    Nishiguchi, I., Sham, T.L., Krempl, E.: A finite deformation theory based on overstress. Parts I and II, in press Journal of Applied Mechanics.Google Scholar
  6. 6.
    Krempl, E., Choi, S.H.: Viscoplasticity theory based on overstress: The modeling of ratchetting and cyclic hardening of type 304 stainless steel, Rensselaer Polytechnic Institute Report MML 90-4, April 1990, submitted to Nuclear Engineering and Design.Google Scholar
  7. 7.
    Majors, P.S., Cheng, S., Ruggles, M.B., Krempl, E.: The rate(time)-dependent mechanical behavior of modified 9Cr-lMo alloy at 538°C and its modeling using the viscoplasticity theory based on overstress, Rensselaer Polytechnic Institute Report MML 90-5, August 1990.Google Scholar

Copyright information

© Springer-Verlag, Berlin Heidelberg 1991

Authors and Affiliations

  • E. Krempl
    • 1
  • P. S. Majors
    • 1
  1. 1.Mechanics of Materials LaboratoryRensselaer Polytechnic InstituteTroyUSA

Personalised recommendations