Strain Hardening Behavior of Ultrafine- Grained Cu by Analyzing the Tensile Stress-Strain Curve

2008 ◽  
Vol 10 (5) ◽  
pp. 434-438 ◽  
Author(s):  
C.-X. Huang ◽  
S.-D. Wu ◽  
S.-X. Li ◽  
Z.-F. Zhang
2018 ◽  
Vol 913 ◽  
pp. 331-339 ◽  
Author(s):  
Ling Kang Ji ◽  
Hui Feng ◽  
Ji Ming Zhang ◽  
Hong Yuan Chen

The strain-hardening performance and characteristics of pipeline steel material have an important influence on the deformation behavior and arrest behavior of the line pipe. In this paper X70, selected, and the longitudinal and transverse tensile stress-strain curve and strain-hardening characteristics were analyzed. The results showed that the strain hardening exponent of the double-phased line pipes derived from the transvers stress-strain curve maintains relatively low level at early stage and increased gradually with variation of strain, which was different from the strain hardening behavior for the rest line pipes in this study. Phase ratio, grain size and dislocation density, precipitation, texture, etc. have an effect to the strain hardening behavior of pipeline steel.


2016 ◽  
Vol 678 ◽  
pp. 215-226 ◽  
Author(s):  
A. Ghatei Kalashami ◽  
A. Kermanpur ◽  
E. Ghassemali ◽  
A. Najafizadeh ◽  
Y. Mazaheri

2005 ◽  
Vol 40 (6) ◽  
pp. 599-607 ◽  
Author(s):  
X. P Huang

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.


1977 ◽  
Vol 9 (6) ◽  
pp. 704-707 ◽  
Author(s):  
V. K. Babich ◽  
V. A. Pirogov ◽  
I. A. Vakulenko

Author(s):  
Digendranath Swain ◽  
S Karthigai Selvan ◽  
Binu P Thomas ◽  
Ahmedul K Asraff ◽  
Jeby Philip

Ramberg-Osgood (R-O) type stress-strain models are commonly employed during elasto-plastic analysis of metals. Recently, 2-stage and 3-stage R-O variant models have been proposed to replicate stress-strain behavior under large plastic deformation. The complexity of these models increases with the addition of each stage. Moreover, these models have considered deformation till necking only. In this paper, a simplistic multi-stage constitutive model is proposed to capture the strain-hardening non-linearity shown by metals including its post necking behavior. The constitutive parameters of the proposed stress-strain model can be determined using only elastic modulus and yield strength. 3-D digital image correlation was used as an experimental tool for measuring full-field strains on the specimens, which were subsequently utilized to obtain the material parameters. Our constitutive model is demonstrated with an aerospace-grade stainless steel AISI 321 wherein deformation response averaged over the gauge length (GL) and at a local necking zone are compared. The resulting averaged and local material parameters obtained from the proposed model provide interesting insights into the pre and post necking deformation behavior. Our constitutive model would be useful for characterizing highly ductile metals which may or may not depict non-linear strain hardening behavior including their post necking deformations.


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