A Generalization of Plastic Flow Theory With Application to Cyclic Hardening and Softening Phenomena

1976 ◽  
Vol 98 (3) ◽  
pp. 221-228 ◽  
Author(s):  
M. A. Eisenberg
Keyword(s):  
Yield Surface ◽  
Kinematic Hardening ◽  
Cyclic Hardening ◽  
304 Stainless Steel ◽  
Multiaxial Loading ◽  
Material Parameters ◽  
Hardening Process ◽  
Cyclic Experiment ◽  
Type 304 ◽  
Type 304 Stainless Steel

A generalization of current theories of plasticity is developed. The theory, applicable to arbitrary multiaxial loading histories, requires a strain controlled uniaxial cyclic experiment to specify the material parameters. In its general form, deformation, translation and rotation of the yield surface are permitted. Detailed calculations are carried out for the simple model of combined isotropic and kinematic hardening of an initial Mises yield surface. This model is shown to provide a quantitative representation of the transient uniaxial cyclic hardening process for type 304 stainless steel at elevated temperature. Implementation of the theory in current FEM structures codes should be straightforward.

Evaluation of Creep Constitutive Equations for Type 304 Stainless Steel Under Repeated Multiaxial Loading

1982 ◽  
Vol 104 (3) ◽  
pp. 159-164 ◽  
Author(s):  
Y. Ohashi ◽  
N. Ohno ◽  
M. Kawai
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Strain Hardening ◽  
Deviatoric Stress ◽  
304 Stainless Steel ◽  
Multiaxial Loading ◽  
Mixed Hardening ◽  
Principal Axes ◽  
Type 304 ◽  
Type 304 Stainless Steel

Four kinds of creep constitutive models, i.e., strain-hardening, modified strain-hardening, kinematic-hardening, and mixed-hardening theory, are evaluated on the basis of creep-test results on type 304 stainless steel at 650°C under repeated multiaxial loading. The predictions of the four models are compared with the experimental results. It is shown that substantial differences appear among these predictions under large rotations of the principal axes of the deviatoric stress tensor, and that none of them can describe with sufficient accuracy the transient increase of strain-rate and the noncollinearity between the deviatoric stress and creep strain-rate vectors which are observed just after the stress-rotations.

Nonproportional Low Cycle Fatigue Criterion for Type 304 Stainless Steel

1995 ◽  
Vol 117 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Takamoto Itoh ◽  
Masao Sakane ◽  
Masateru Ohnami ◽  
Darrell F. Socie
Keyword(s):  
Stainless Steel ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Nonproportional Loading ◽  
Loading Tests ◽  
Strain Paths ◽  
Type 304 ◽  
Type 304 Stainless Steel

This paper describes a multiaxial low cycle fatigue parameter for correlating Hues under nonproportional loadings. Constant amplitude low cycle fatigue tests were carried out under 14 proportional and complex nonproportional cyclic strain paths using type 304 stainless steel hollow cylinder specimens at room temperature. In nonproportional loading tests, fatigue lives are decreased by as much as a factor of 10 in comparison with those in proportional loading tests with the same strain range. Reduction in fatigue life due to nonproportional loading is closely related to additional nonproportional cyclic hardening. The product of the maximum principal stress and strain ranges correlated the nonproportional fatigue data. A nonproportional cyclic hardening parameter computed from the strain path is also proposed that allows life estimates to be obtained directly from the strain history without the need for a cyclic plasticity model.

On a Class of Kinematic Hardening Rules for Nonproportional Cyclic Plasticity

1989 ◽  
Vol 111 (1) ◽  
pp. 87-98 ◽  
Author(s):  
J. C. Moosbrugger ◽  
D. L. McDowell
Keyword(s):  
Kinematic Hardening ◽  
Cyclic Plasticity ◽  
304 Stainless Steel ◽  
Image Point ◽  
Isotropic Hardening ◽  
Proportional Loading ◽  
Modeling Material ◽  
Hardening Rules ◽  
Type 304 ◽  
Type 304 Stainless Steel

Two surface theories for rate-independent plasticity have previously been shown to offer superior correlative capability in modeling material response under non-proportional loading. In this study, a class of kinematic hardening rules characterized by a decomposition of the total kinematic hardening variable is discussed. The concept of generalized image point hardening in conjunction with mulitple loading surface interpretations is presented. The ability of this class of rules to correlate experimental data from stable nonproportional cycling of Type 304 stainless steel at room temperature is examined. In addition, the proper framework for inclusion of isotropic hardening for this class of models is discussed.

Anisotropic Nonlinear Kinematic Hardening Rule Parameters From Reversed Proportional Axial-Torsional Cycling

1999 ◽  
Vol 122 (1) ◽  
pp. 18-28 ◽  
Author(s):  
J. C. Moosbrugger
Keyword(s):  
Kinematic Hardening ◽  
Transverse Isotropy ◽  
Cyclic Plasticity ◽  
304 Stainless Steel ◽  
Hardening Rule ◽  
Thin Walled ◽  
Hardening Rules ◽  
Type 304 ◽  
Type 304 Stainless Steel ◽  
Tubular Specimens

A procedure for determining parameters for anisotropic forms of nonlinear kinematic hardening rules for cyclic plasticity or viscoplasticity models is described. An earlier reported methodology for determining parameters for isotropic forms of uncoupled, superposed Armstrong-Frederick type kinematic hardening rules is extended. For this exercise, the anisotropy of the kinematic hardening rules is restricted to transverse isotropy or orthotropy. A limited number of parameters for such kinematic hardening rules can be determined using reversed proportional tension-torsion cycling of thin-walled tubular specimens. This is demonstrated using tests on type 304 stainless-steel specimens and results are compared to results based on the assumption of isotropic forms of the kinematic hardening rules. [S0094-4289(00)00301-7]

scholarly journals A Simple Inelastic Constitutive Model for Evaluation of Stable Cyclic Stress Response Under Nonproportional Straining

2002 ◽  
Author(s):  
Masao Sakane ◽  
Takamoto Itoh ◽  
Xu Chen
Keyword(s):  
Kinematic Hardening ◽  
Cyclic Stress ◽  
304 Stainless Steel ◽  
Surface Model ◽  
Cyclic Stress Response ◽  
Strain Relationship ◽  
Strain Paths ◽  
Hardening Rules ◽  
Type 304 ◽  
Type 304 Stainless Steel

This paper proposes a simple two-surface model for cyclic incremental plasticity based on combined Mroz and Ziegler kinematic hardening rules under nonproportional loading. The model has only seven material constants and a nonproportional factor which describes the degree of additional hardening. Cyclic loading experiments with fourteen strain paths were conducted using Type 304 stainless steel. The simulation has shown that the model was precise enough to calculate the stable cyclic stress-strain relationship under nonproportional loadings.

Application of the Hybrid Constitutive Model for Cyclic Plasticity to Sinusoidal Loading

1992 ◽  
Vol 114 (2) ◽  
pp. 172-179 ◽  
Author(s):  
H. Ishikawa ◽  
K. Sasaki
Keyword(s):  
Constitutive Model ◽  
Yield Surface ◽  
Strain Path ◽  
Good Description ◽  
Yield Function ◽  
Cyclic Plasticity ◽  
304 Stainless Steel ◽  
Subsequent Yield Surface ◽  
Type 304 ◽  
Type 304 Stainless Steel

In order to study the applicability of the proposed hybrid constitutive model for cyclic plasticity to nonproportional loading, type 304 stainless-steel specimens subjected to sinusoidal loading that could change the degree of nonproportionality of the strain path were examined in detail. The subsequent yield surface during the loading was discussed in advance because the plastic deformation induced anisotropy coefficient tensor in the yield function had to be determined from the yield surface obtained by the experiment. From the experimental results, the subsequent yield surfaces during the loading could be assumed to be of the quadratic form of stress. The simulations based on the model gave a good description of the sinusoidal loading, irrespective of the degree of nonproportionality of the strain path.

A Constitutive Model for Anisotropic Creep Deformation

1994 ◽  
Vol 116 (2) ◽  
pp. 142-147 ◽  
Author(s):  
M. Kawai
Keyword(s):  
Kinematic Hardening ◽  
Back Stress ◽  
Point Of View ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Stress Deviator ◽  
Stress Changes ◽  
Type 304 ◽  
Type 304 Stainless Steel ◽  
Anisotropic Creep

Anisotropic creep behavior of polycrystalline metals under repeated stress changes is modeled from a phenomenological point of view. The creep model consists of basic constitutive equations (BCE) and an auxiliary hardening rule (AUX) to enhance the predictive capability of the BCE. The BCE is characterized by a kinematic hardening variable which is defined as the sum of two component variables; one represents the back stress and the other a flow resistance in the opposite direction of the stress deviator. The AUX is governed by a memory region in which only the evolution of the back stress takes place. The validity of the creep model is discussed on the basis of simulations for multiaxial nonproportional repeated creep of type 304 stainless steel at 650°C.

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