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To obtain the exact mechanical properties of TC4 titanium alloy, the compression experiments on TC4 titanium alloy at different strain rates (10-2,10-3,10-4 s-1) were performed at room-temperature on the MTS-810 electrohydraulic servo material testing machine. The data of TC4 titanium alloy compression experiments at different rates were obtained. And furthermore Johnson-Cook constitutive model is established. Due to different conditions, the equation is simplified, the constitutive parameters are obtained by step-by-step estimation method, and the Johnson-Cook (JC) constitutive model of TC4 titanium alloy at room temperature is established. The prediction results of the model were compared with the experimental data, the prediction curve is in good agreement, which verifies the feasibility of the model. [ABSTRACT FROM AUTHOR]

Using Gleeble-3800 thermal simulation testing machine, the TC4 titanium alloy was subjected to hot compression experiments under the conditions of deformation temperature of 810 – 950 °C, strain rate of 0.001 - 1s-1. The research shows that the flow stress of TC4 titanium alloy is more sensitive to the deformation temperature and strain rate during thermal deformation, and it increases with the decrease of the deformation temperature and the increase of the strain rate. Based on BP neural network, a constitutive model of TC4 titanium alloy α+β two-phase region is established. The correlation coefficient reaches 0,996, which proves that the model can predict the high temperature flow stress of TC4 titanium alloy. [ABSTRACT FROM AUTHOR]

The Gleeble – 3500 thermal simulation testing machine was used to perform isothermal tensile test on 7075 aluminum alloy at a deformation temperature of 300 – 450 °C and a strain rate of 0,01 – 1 s-1, and the true stress-strain curve of the alloy was obtained. Based on the true stress-strain data, the modified Zerilli-Armstrong (M-ZA) model was used to construct the constitutive model of the alloy, and the fitting accuracy of the model was analyzed. [ABSTRACT FROM AUTHOR]

Use Gleeble-3800 thermal simulation test machine to conduct thermal tensile test on 6005A aluminum alloy at 623~723 K and 0,01~1 s-1 strain rate. Using the obtained true stress-strain curve, the modified Zerilli-Armstrong (m- Z-A) model considering strain compensation was used to construct the constitutive model of the alloy. The results show that the correlation coefficient and average absolute error of the m-Z-A model are 0,97311 and 4,1779 %, respectively. The experimental data is in good agreement with the predicted curve obtained by calculating the model, which verifies the feasibility of the model. [ABSTRACT FROM AUTHOR]

The deformation behavior of 6005A aluminum alloy at a strain rate of 0,01-10s-1, a deformation temperature of 673- 773K and a total strain of 0,8 was studied. Using the stress-strain data of 6005A aluminum alloy with a strain of 0,05- 0,8, an Arrhenius-type constitutive model was established. And verified the accuracy of the model. The results show that: the flow stress of 6005A aluminum alloy increases with the increase of strain rate, and decreases with the increase of deformation temperature; Under different strains, the correlation coefficient (R) between the experimental value and the predicted value is as high as 98 %, and the average relative error (AARE) is less than 10 %, indicating that the established model has high predictability. [ABSTRACT FROM AUTHOR]

The 3Cr23Ni8Mn3N heat-resistant steel was subjected to isothermal constant strain rate compression experiments using a Gleeble - 1 500D thermal simulator. The thermal deformation behavior in the range of deformation temperature 1 000 - 1 180 °C and strain rate 0,01 - 10 s-1 was studied. Based on experimental data, the stress-strain curves of 3Cr23Ni8Mn3N were established. And the constitutive relation of BP neural network (3 × 10 × 10 × 1) was constructed. The flow stress was predicted and compared by the ANN constitutive model. The correlation coefficient (R) is 0,999, and the average relative error (AARE) is 0,697%. The results show that the ANN constitutive model has high accuracy for predicting the thermal deformation behavior of 3Cr23Ni8Mn3N. The model can provide a good reference value for thermal processing. [ABSTRACT FROM AUTHOR]

The downhole expansion process of the expansion tube is the dynamic deformation process of the expansion tube metal material at different temperatures. In this paper, the dynamic tensile test is used to measure the dynamic tensile stress-strain curve of low-carbon alloy steel in the temperature range of 25 - 300 °C. upon analyzed the dynamic tensile test results, with the strain rate factor Z and McCormick physical model, the paper set up low carbon alloy steel constitutive equation of underground temperature field. The calculation results of the Sellars creep equation are compared with the residual stress value after expansion in the finite element analysis of the solid steel pipe expansion to verify the actual application reliability of the steel for the expansion pipe with high expansion rate. [ABSTRACT FROM AUTHOR]

Use Gleeble-1500D thermal simulation test machine to conduct thermal tensile test on AISI 1035 in the deformation temperature range of 1 173,15~1 373,15 K and strain rate range of 0,2 ~ 20 s-1. Using the obtained true stress-strain curves, an intrinsic model of the material was constructed using a model considering strain compensation. The results showed that the correlation coefficient of the Arrhenius model of AISI 1035 considering strain compensation was 0,984 with an average absolute error of 3,550 %, which can accurately predict the flow profitability. The experimental data matched well with the prediction curves obtained from the model calculation, which verified the feasibility of the model [ABSTRACT FROM AUTHOR]

At the deformation temperature of 1 103-1 283 K, with strain rate of 0,01 - 10 s-1, and total strain of 0,7, the deformation behavior of TC6 titanium alloy was studied. The Arrhenius constitutive model is established by using stress - strain data when the strains of TC6 titanium alloy are 0,05, 0,1, 0,2, 0,3, 0,4, 0,5, 0,55, 0,6, and the accuracy of the model was verified. The results show that: the flow stress of TC6 titanium alloy increases as the strain rate increases and decreases as the deformation temperature increases; under different strains, the correlation coefficient (R) between the experimental value and the predicted value is greater than 98%, and the average relative error (AARE) is lower than 10%, which suggests that the established model has a higher prediction. [ABSTRACT FROM AUTHOR]

The hot compression test was conducted in Gleeble-1 500D to study the hot flow stress behavior of AA6 111 aluminum alloy belonging to Al-Mg-Si series, at the deformation temperatures ranging from 350 to 500 °C and strain rates ranging from 0,01 s-1 to 1 s-1. And how the flow stress change with variation of strain, temperature and strain rate was investigated. The results show that flow stress increases with decreasing temperature and increasing strain rate; the AA6 111 is positive stain rate sensitive material; the main softening mechanism is dynamic recovery. Furthermore, constitutive equation considering the effect of strain was obtained based on Arrhenius equation. The predicted flow stress values well agree with the experimental results with some little aberration. The coefficient of association can be as high as 0,9 954, which shows high reference value for industry and simulation analysis. [ABSTRACT FROM AUTHOR]