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Ratchetting behavior in viscoplasticity - A technical noteViscoplastic models that use the Armstrong and Frederick (1966) kinematic hardening relationship are known to generally overpredict the observed accumulation of ratchet strains. The reason for this behavior is a consequence of the mathematics used to describe Hooke's law and the evolution equations for plastic strain and back stress. Conditions for ratchetting exist whenever there is a cycle-averaged mean stress present over a cyclic loading path. Two types of controlled loading paths are often studied: cyclic relaxation is the ratchet mechanism associated with displacement (strain) control, while cyclic creep is the ratchet mechanism associated with load (stress) control. Overcoming the possible adverse trends in predicted ratchetting behavior is a difficult task, and how one ought to go about doing this is not yet completely clear. We therefore choose to discuss the mathematical cause of ratchetting and how it has been dealt with to date, but make no attempt to correct this flaw.
Document ID
19930059654
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Freed, Alan D.
(NASA Lewis Research Center Cleveland, OH, United States)
Walker, Kevin P.
(Engineering Science Software, Inc. Smithfield, RI, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Publication Information
Publication: European Journal of Mechanics, A/Solids
Volume: 12
Issue: 2
ISSN: 0997-7538
Subject Category
Structural Mechanics
Accession Number
93A43651
Funding Number(s)
CONTRACT_GRANT: DE-AC02-88ER-13895
Distribution Limits
Public
Copyright
Other

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