Survey of plateau behaviour in the cyclic stress-strain curve of copper single crystals

A simplified treatment is presented for the analysis of tubular specimens subject to in-phase tension-torsion loads in the elasto-plastic regime. Use is made of a hardening function readily obtainable from the uniaxial cyclic stress-strain curve and hysteresis loops. Expressions are given for incremental as well as deformation theories of plasticity. The reversals of loading are modelled by referring the flow equations to the point of reversal and calculating distances from the point of reversal using a yield critertion. The method has been used to predict the deformation response of in-phase tests on an En15R steel, and comparisons with experimental data are provided. The material exhibited a non-Masing type behaviour. A power law rule is developed for predicting multiaxial cyclic response from uniaxial data by incorporating a hysteretic strain hardening exponent.

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Effect of grain size and ramp loading on the low-amplitude cyclic stress-strain curve of polycrystalline copperLlanes, L. and Laird, C. Mater. Sci. Eng. A Sept. 1990 128A, (2), L9–L12

International Journal of Fatigue ◽

10.1016/0142-1123(91)90684-q ◽

1991 ◽

Vol 13 (5) ◽

pp. 436-436

Keyword(s):

Grain Size ◽

Strain Curve ◽

Cyclic Stress ◽

Stress Strain Curve ◽

Stress Strain ◽

Low Amplitude

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A Continuum Model for Single Crystal Cyclic Plasticity

MRS Proceedings ◽

10.1557/proc-779-w5.30 ◽

2003 ◽

Vol 779 ◽

Author(s):

Biqiang Xu ◽

Yanyao Jiang

Keyword(s):

Single Crystal ◽

Single Crystals ◽

Kinematic Hardening ◽

Strain Curve ◽

Cyclic Behavior ◽

Cyclic Plasticity ◽

Amplitude Dependence ◽

Slip Systems ◽

Stress Strain ◽

Copper Single Crystals

AbstractA constitutive model was developed to bridge the cyclic plasticity behavior of single crystals and the corresponding characteristic dislocation structures. Yield and flow were built on the individual slip systems. The Armstrong-Frederick kinematic hardening rule was invoked to capture the Bauschinger effect. A material memory parameter was introduced to consider the amplitude dependence of cyclic hardening. Latent hardening considering the interactions among the slip systems was used to describe the anisotropic cyclic behavior. The experimental results of copper single crystals were used to validate the model developed. It was found that the model was able to adequately describe the well-known three distinctive regions in the cyclic stress-strain curve of the FCC single crystal oriented for single slip and the associated dislocation substructures. The model was capable of capturing the enhanced hardening observed in copper single crystals in multi-slip orientations. For a given loading history, the model can predict not only the saturated stress-strain response but also the detailed evolution of the transient cyclic behavior. The characteristic dislocation structures can be featured with the slip evolution.

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