A Constitutive Model Research Based on Dislocation Mechanism of 5083 Aluminum Alloy

2017 ◽  
Vol 35 (02) ◽  
pp. 145-152
Author(s):  
N. Gao ◽  
Z. Zhu ◽  
S. Xiao ◽  
Q. Xie
Keyword(s):  
Aluminum Alloy ◽  
Constitutive Model ◽  
Plastic Flow ◽  
Test System ◽  
Dislocation Dynamics ◽  
Strain Rates ◽  
Prediction Ability ◽  
Yield Behavior ◽  
Wide Range ◽  
5083 Aluminum Alloy

ABSTRACTThe study of the mechanical properties of polycrystalline alloy materials under dynamic impact, namely, the prediction of mechanical behavior after yield stress and the establishment of a constitutive model, has attracted much attention in the field of engineering. The stress-strain curves of 5083 aluminum alloy were obtained under strain rates varying from 0.0002 s-1 to 7130 s-1 through uniaxial compression experiments. The equipment used included a CRIMS RPL100 tester, Instron tester, and split Hopkinson test system. In addition, based on dislocation dynamics and the strengthening mechanism of metals, the plastic flow of the 5083 aluminum alloy was systematically analyzed under a wide range of strain rates. It was found that the abnormal yield behavior of the 5083 aluminum alloy under a wide range of strain rates increased, and the experimental phenomenon of hardening rate decreased with an increase in strain rate. This study also revealed that the abnormal yield behavior is caused by the different dislocation mechanisms of two-phase alloy elements under different strain rates. Based on the thermal activation theory and the experimental data, a constitutive model was developed. A comparison showed good agreement between the experimental and model curves. This indicates that this model has good plastic flow stress prediction ability for such types of materials.

Constitutive Modeling for Elevated Temperature Flow Behavior of ZHMn34-2-2-1 Manganese Brass

2017 ◽  
Vol 872 ◽  
pp. 30-37
Author(s):  
Meng Han Wang ◽  
Kang Wei ◽  
Xiao Juan Li
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rates ◽  
Hollomon Parameter ◽  
Prediction Ability ◽  
Absolute Relative Error ◽  
Deformation Behaviors ◽  
State Stress

The hot compressive deformation behaviors of ZHMn34-2-2-1 manganese brass are investigated on Thermecmastor-Z thermal simulator over wide processing domain of temperatures (923K-1073K) and strain rates (0.01s-1-10s-1). The true stress-strain curves exhibit a single peak stress, after which the stress monotonously decreases until a steady state stress occurs, indicating a typical dynamic recrystallization. A revised constitutive model coupling flow stress with strain, strain rate and deformation temperature is established with the material constants expressed by polynomial fitting of strain. Moreover, better prediction ability of the constitutive model is achieved by implementation of a simple approach for modified the Zener-Hollomon parameter considering the compensation of strain rate and temperature increment. By comparing the predicted and experimented values, the correlation coefficient and mean absolute relative error are 0.997 and 2.363%, respectively. The quantitative statistical results indicate that the proposed constitutive model can precisely characterize the hot deformation behavior of ZHMn34-2-2-1 manganese brass.

Modeling of flow behavior for 7050-T7451 aluminum alloy considering microstructural evolution over a wide range of strain rates

2016 ◽  
Vol 95 ◽  
pp. 146-157 ◽  
Author(s):  
Guang Chen ◽  
Chengzu Ren ◽  
Zhihong Ke ◽  
Jun Li ◽  
Xinpeng Yang
Keyword(s):  
Aluminum Alloy ◽  
Microstructural Evolution ◽  
Flow Behavior ◽  
Strain Rates ◽  
Wide Range

Plastic Flow Stress and Constitutive Model for H96 Brass Alloy

2015 ◽  
Vol 782 ◽  
pp. 130-136 ◽  
Author(s):  
Ping Zhou ◽  
Wei Guo Guo ◽  
Hai Hui Wu
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Plastic Flow ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Experimental Results ◽  
Dynamic Strain ◽  
Strain Rates ◽  
Brass Alloy ◽  
Plastic Flow Stress

To explore the thermo-mechanical response of H96 brass alloy, the quasi-static (universal-testing machine) and dynamic (the split Hopkinson pressure bar apparatus) uniaxial compression experiments have been performed under the temperatures from 293 K to 873 K and the strain rates from 0.001 s-1 to 6000 s-1, and the strains over 60% are obtained. Results show that, H96 brass alloy has strong strain hardening behavior, and it becomes weaker with the increasing temperature. In addition, this alloy is sensitive to strain rates; and, it has temperature sensitivity, the dynamic strain aging occurs at the temperature of 473 K and a quasi-static strain rate of 0.001 s-1. Based on the thermal activation dislocation mechanism, paralleled with the experimental results, a plastic flow constitutive model with the physical conception is developed. The model is suitable to predict the plastic flow stress at different temperatures and strain rates. According to comparing results, the model predictions are in good agreement with the experimental results.

scholarly journals A Micromechanics Based Constitutive Model for Brittle Failure at High Strain Rates

2012 ◽  
Vol 79 (3) ◽  
Author(s):  
Harsha S. Bhat ◽  
Ares J. Rosakis ◽  
Charles G. Sammis
Keyword(s):  
Constitutive Model ◽  
Damage Mechanics ◽  
Time Derivative ◽  
Rate Sensitivity ◽  
Model Parameters ◽  
Strain Rates ◽  
Failure Strength ◽  
Loading Rates ◽  
Brittle Solids ◽  
Wide Range

The micromechanical damage mechanics formulated by Ashby and Sammis, 1990, “The Damage Mechanics of Brittle Solids in Compression,” Pure Appl. Geophys., 133(3), pp. 489–521, and generalized by Deshpande and Evans 2008, “Inelastic Deformation and Energy Dissipation in Ceramics: A Mechanism-Based Constitutive Model,” J. Mech. Phys. Solids, 56(10), pp. 3077–3100. has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over strain rates ranging from ∼10− 6to 103s− 1. Model parameters determined from quasi-static experiments were used to predict the failure strength at higher loading rates. Agreement with experimental results was excellent.

Mechanical Response of AA7075 Aluminum Alloy over a Wide Range of Temperatures and Strain Rates

2000 ◽  
Vol 331-337 ◽  
pp. 527-532 ◽  
Author(s):  
Zhe Jin ◽  
William A. Cassada ◽  
Carl M. Cady ◽  
George T. Gray III
Keyword(s):  
Aluminum Alloy ◽  
Mechanical Response ◽  
Strain Rates ◽  
Wide Range
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