Cycle-Dependent Ratcheting Under Multiaxial Loads Including the Bauschinger Effect and Nonlinear Strain Hardening

2009 ◽  
pp. 298-298-12
Author(s):  
YS Garud
Keyword(s):  
Strain Hardening ◽  
Bauschinger Effect ◽  
Nonlinear Strain ◽  
Cycle Dependent

Thermoelastoplastic Stress Analysis of a Thick-Walled Tube of Nonlinear Strain Hardening

1996 ◽  
Vol 118 (3) ◽  
pp. 340-346 ◽  
Author(s):  
S. Jahanian
Keyword(s):  
Strain Hardening ◽  
Nuclear Power ◽  
Power Plants ◽  
Rapid Heating ◽  
Numerical Procedure ◽  
Temperature Dependent ◽  
Nonlinear Strain ◽  
Elastic Approximation

In pressure vessel technology or nuclear power plants, some of the mechanical components are often subjected to rapid heating. If the temperature gradient during such process is high enough, thermoelastoplastic stresses may be developed in the components. These plastic deformations are permanent and may result in the incremental deformation of the structure in the long term. Accordingly, determination of thermoelastoplastic stresses during this process is an important factor in design. In this paper, a thick-walled cylinder of nonlinear strain hardening is considered for the thermoelastoplastic analysis. The properties of the material are assumed to be temperature dependent. The cylinder is subject to rapid heating of the inside surface while the outside surface is kept at the room temperature. A quasi-static and uncoupled thermoelastoplastic analysis based on incremental theory of plasticity is developed and a numerical procedure for successive elastic approximation is presented. The thermoelastoplastic stresses developed during this process are also presented. The effect of strain hardening and temperature dependency of material on the results are investigated.

The Bauschinger Effect in a High-Strength Steel

1966 ◽  
Vol 88 (2) ◽  
pp. 480-488 ◽  
Author(s):  
R. V. Milligan ◽  
W. H. Koo ◽  
T. E. Davidson
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
Strain Hardening ◽  
Uniaxial Tension ◽  
High Strength Steel ◽  
Bauschinger Effect ◽  
High Strength ◽  
The Other ◽  
Material Structure ◽  
Permanent Strain

The object of this work was to evaluate quantitatively the Bauschinger effect in a 4330 modified steel as a function of strength level and structure as derived from variations in heat-treatment. Material having martensitic, pearlitic, and bainitic structures was studied utilizing a uniaxial tension-compression specimen. Various ways of defining the magnitude of the Bauschinger effect are explained. One is a conventional approach as suggested by Welter, the other a technique which takes strain-hardening into account. The results show the Bauschinger effect to be independent of yield strength for three different strength levels of the martensitic material. It is only mildly influenced by material structure and independent of the direction of overstrain. The Bauschinger effect increases with increasing permanent strain up to approximately 2 percent and thereafter remains essentially constant.

A General Autofrettage Model of a Thick-Walled Cylinder Based on Tensile-Compressive Stress-Strain Curve of a Material

2005 ◽  
Vol 40 (6) ◽  
pp. 599-607 ◽  
Author(s):  
X. P Huang
Keyword(s):  
Strain Hardening ◽  
Compressive Stress ◽  
Bauschinger Effect ◽  
Strain Curve ◽  
Accurate Prediction ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Perfectly Plastic ◽  
Hardening Models ◽  
Elastic Perfectly Plastic

The basic autofrettage theory assumes elastic-perfectly plastic behaviour. Because of the Bauschinger effect and strain-hardening, most materials do not display elastic-perfectly plastic properties and consequently various autofrettage models are based on different simplified material strain-hardening models, which assume linear strain-hardening or power strain-hardening or a combination of these strain-hardening models. This approach gives a more accurate prediction than the elastic-perfectly plastic model and is suitable for different strain-hardening materials. In this paper, a general autofrettage model that incorporates the material strain-hardening relationship and the Bauschinger effect, based upon the actual tensile-compressive stress-strain curve of a material is proposed. The model incorporates the von Mises yield criterion, an incompressible material, and the plane strain condition. Analytic expressions for the residual stress distribution have been derived. Experimental results show that the present model has a stronger curve-fitting ability and gives a more accurate prediction. Several other models are shown to be special cases of the general model presented in this paper. The parameters needed in the model are determined by fitting the actual tensile-compressive curve of the material, and the maximum strain of this curve should closely represent the maximum equivalent strain at the inner surface of the cylinder under maximum autofrettage pressure.

Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels

2012 ◽  
Vol 551 ◽  
pp. 192-199 ◽  
Author(s):  
Seung Youb Han ◽  
Seok Su Sohn ◽  
Sang Yong Shin ◽  
Jin-ho Bae ◽  
Hyoung Seop Kim ◽  
...  
Keyword(s):  
Strain Hardening ◽  
Bauschinger Effect ◽  
Yield Ratio ◽  
Linepipe Steels

Thermal Ratcheting of a Beam Element Having an Idealized Bauschinger Effect

1976 ◽  
Vol 98 (3) ◽  
pp. 264-271 ◽  
Author(s):  
T. M. Mulcahy
Keyword(s):  
Strain Hardening ◽  
Temperature Variation ◽  
Bauschinger Effect ◽  
Rectangular Cross Section ◽  
Beam Element ◽  
Operating Conditions ◽  
Hardening Material ◽  
Linear Temperature ◽  
Thermal Ratcheting ◽  
Breeder Reactors

Thermal ratcheting has been analytically investigated for a beam element subjected to a linear temperature variation across its solid rectangular cross section. A linear strain-hardening material response exhibiting an idealized Bauschinger effect was assumed. Formulas are given for the associated strain accumulation which are valid over a large range of strain hardening, temperature variation, temperature cycles, and axial load. Specific results are tabulated for the materials and operating conditions typically associated with liquid metal breeder reactors.

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