scholarly journals A Flow Stress Model of 300M Steel for Isothermal Tension

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 252
Author(s):  
Rongchuang Chen ◽  
Shiyang Zhang ◽  
Xianlong Liu ◽  
Fei Feng
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Tensile Deformation ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Average Deviation ◽  
Cross Sectional ◽  
300M Steel

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C) and strain rates (0.01 s−1, 0.1 s−1, 1 s−1, 10 s−1). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, α, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

Development and application of hyperelastic model for diaphragm considering the influence of temperature

2019 ◽  
Vol 08 (03) ◽  
pp. 1950010
Author(s):  
Lidong Wang ◽  
Xiongqi Peng ◽  
Mingrui Liu
Keyword(s):  
Constitutive Model ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Influence Of Temperature ◽  
Nonlinear Fitting ◽  
Element Simulation ◽  
Hyperelastic Model ◽  
User Material Subroutine ◽  
Solid Foundation

The basic mechanical properties of a diaphragm under various temperatures in hot diaphragm preforming of composites are obtained by uniaxial tensile tests. A constitutive model considering the influence of temperature is accordingly developed to characterize its large deformation behavior. Model parameters are obtained by nonlinear fitting experiment data. The constitutive model is implemented in ABAQUS through the user material subroutine UHYPER. The developed constitutive model is verified by simulating the covering deformation of the diaphragm over a C-type mold. Finally, as an application of the developed hyperelastic model, an optimal design of a support bar in the hot diaphragm preforming process is implemented. The constitutive model lays a solid foundation for the finite element simulation and process optimization of the hot diaphragm forming (HDF) of carbon composites.

Linear analysis of parameters in Arrhenius model for Ti-6Al-4V at superplastic forming

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junzhou Yang ◽  
Jianjun Wu ◽  
Qianwen Zhang ◽  
Yinxiang Ren ◽  
Han Ruolan ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Flow Behavior ◽  
Superplastic Forming ◽  
Tensile Tests ◽  
Model Parameters ◽  
Content Type ◽  
Forming Mechanism ◽  
Good Ability ◽  
Titanium Material ◽  
High Temperature Tensile

Purpose With the discussion on the linear relationship of determined material parameters, this study aims to propose a new method to analyze the deformation mechanism. Design/methodology/approach A modified constitutive model based on the hyperbolic sine Arrhenius equation has been established, which is applied to describe the flow behavior of Ti-6Al-4V alloy during the superplastic forming (SPF). Findings The modified constitutive model in this work has a good ability to describe the flow behavior for Ti-6Al-4V in SPF. Besides, a deformation map of titanium material is obtained based on the parameters. As the supplement, finite element models of high-temperature tensile tests are carried out as the application of the constitutive model. Originality/value The relationship between constitutive model parameters and forming mechanism is established, which is a new angle in rheological behavior research and constitutive model analysis.

Elasto-viscoplastic constitutive equations for the description of glassy polymers behavior at constant strain rate

2006 ◽  
Vol 129 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Fahmi Zaïri ◽  
Moussa Naït-Abdelaziz ◽  
Krzysztof Woznica ◽  
Jean-Michel Gloaguen
Keyword(s):  
Constitutive Equations ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Glassy Polymers ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Strain Rates ◽  
State Variable ◽  
Rubber Toughened ◽  
Compressive Tests

In this study, a modelization of the viscoplastic behavior of amorphous polymers is proposed, from an approach originally developed for metal behavior at high temperature, in which state variable constitutive equations have been modified. A procedure for the identification of model parameters is developed through the use of experimental data from both uniaxial compressive tests extracted from the literature and uniaxial tensile tests performed in this study across a variety of strain rates. The numerical algorithm shows that the predictions of this model well describe qualitatively and quantitatively the intrinsic softening immediately after yielding and the subsequent progressive orientational hardening corresponding to the response of two polymers, amorphous polyethylene terephthalate and rubber toughened polymethyl methacrylate.

Tensile Deformation Behavior of 5A90 Al-Li Alloy Sheet at Elevated Temperature

2011 ◽  
Vol 66-68 ◽  
pp. 70-75 ◽  
Author(s):  
Gao Shan Ma ◽  
Song Yang Zhang ◽  
Han Ying Wang ◽  
Min Wan
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Alloy Sheet ◽  
Hot Forming ◽  
Uniaxial Tensile ◽  
Sensitivity Index ◽  
Tensile Deformation Behavior ◽  
Increasing Temperature

Uniaxial tensile deformation behavior of 5A90 aluminium-lithium alloy sheet is investigated in the hot forming with the temperature range of 200-450°C and strain rate range of 0.3×10-3-0.2×10-1s-1. It is found that the flow stress of 5A90 Al-Li alloy in uniaxial tension increase with increasing strain rate and decrease with increasing temperature, however, the tendency of total elongation is just the reverse, and the optimum forming temperature is 400°C. The strain rate sensitivity index (m-value) remarkably increases with increasing temperature for a given strain rate. It is shown that 5A90 Al-Li alloy sheet displays the sensitivity to the strain rate at elevated temperatures. For a given strain rate, the strain hardening index (n-value) decreases with increasing temperature, whereas the n-value increases above 350°C. The constitutive equation of stress, strain and strain rate for 5A90 Al-Li alloy at any temperature is obtained by fitting the experimental data, which gave a good flow stress model for the FEM simulation of hot forming.

scholarly journals Johnson Cook Material and Failure Model Parameters Estimation of AISI-1045 Medium Carbon Steel for Metal Forming Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 609 ◽  
Author(s):  
Mohanraj Murugesan ◽  
Dong Jung
Keyword(s):  
Flow Stress ◽  
Metal Forming ◽  
Flow Behavior ◽  
Medium Carbon Steel ◽  
Material Behavior ◽  
Model Parameters ◽  
Stress Model ◽  
Medium Carbon ◽  
Aisi 1045 ◽  
Flow Stress Model

Consistent and reasonable characterization of the material behavior under the coupled effects of strain, strain rate and temperature on the material flow stress is remarkably crucial in order to design as well as optimize the process parameters in the metal forming industrial practice. The objective of this work was to formulate an appropriate flow stress model to characterize the flow behavior of AISI-1045 medium carbon steel over a practical range of deformation temperatures (650–950 ∘ C) and strain rates (0.05–1.0 s − 1 ). Subsequently, the Johnson-Cook flow stress model was adopted for modeling and predicting the material flow behavior at elevated temperatures. Furthermore, surrogate models were developed based on the constitutive relations, and the model constants were estimated using the experimental results. As a result, the constitutive flow stress model was formed and the constructed model was examined systematically against experimental data by both numerical and graphical validations. In addition, to predict the material damage behavior, the failure model proposed by Johnson and Cook was used, and to determine the model parameters, seven different specimens, including flat, smooth round bars and pre-notched specimens, were tested at room temperature under quasi strain rate conditions. From the results, it can be seen that the developed model over predicts the material behavior at a low temperature for all strain rates. However, overall, the developed model can produce a fairly accurate and precise estimation of flow behavior with good correlation to the experimental data under high temperature conditions. Furthermore, the damage model parameters estimated in this research can be used to model the metal forming simulations, and valuable prediction results for the work material can be achieved.

Research on the High Temperature Constitutive Model of 300M Ultrahigh Strength Steel

2016 ◽  
Vol 836-837 ◽  
pp. 484-492
Author(s):  
Hui Ping Zhang ◽  
Na Zhao ◽  
Xu Shi ◽  
Xiao Lei Zhang ◽  
Yi Ren
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Thermal Deformation ◽  
Strain Curve ◽  
Peak Stress ◽  
Stress Strain Curve ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel ◽  
300M Steel

300M ultrahigh strength steel has good mechanical properties. It has been widely used in the force bearing components of aircraft. In this paper, By using Gleeble1-500D thermal simulator, we studied the change regularity of stress-strain curve of 300M steel using hot compression deformation when temperature is from 800°C to1100°C, strain rate is from 0.001 S-1to 1 S-1 and the strain is 0.7.The experimental results showed that when the strain rate is constant, the flow stress and the peak stress decrease with the increase of deformation temperature. When the deformation temperature is constant, the flow stress and peak stress increase with the increase of strain rate. From the test, we got the true stress-strain curve, calculated the thermal deformation constants such as the deformation activation energy of 300M ultrahigh strength steel. Eventually, we built the thermal deformation constitutive model in hyperbolic sine form of 300M steel.

scholarly journals Strain Rate-Dependent Constitutive and Low Stress Triaxiality Fracture Behavior Investigation of 6005 Al Alloy

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yong Peng ◽  
Xuanzhen Chen ◽  
Shan Peng ◽  
Chao Chen ◽  
Jiahao Li ◽  
...  
Keyword(s):  
Flow Stress ◽  
Plastic Strain ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Equivalent Plastic Strain ◽  
Stress Triaxiality ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Stress States

In order to study the dynamic and fracture behavior of 6005 aluminum alloy at different strain rates and stress states, various tests (tensile tests at different strain rates and tensile shearing tests at five stress states) are conducted by Mechanical Testing and Simulation (MTS) and split-Hopkinson tension bar (SHTB). Numerical simulations based on the finite element method (FEM) are performed with ABAQUS/Standard to obtain the actual stress triaxialities and equivalent plastic strain to fracture. The results of tensile tests for 6005 Al show obvious rate dependence on strain rates. The results obtained from simulations indicate the feature of nonmonotonicity between the strain to fracture and stress triaxiality. The equivalent plastic strain reduces to a minimum value and then increases in the stress triaxiality range from 0.04 to 0.30. A simplified Johnson-Cook (JC) constitutive model is proposed to depict the relationship between the flow stress and strain rate. What is more, the strain-rate factor is modified using a quadratic polynomial regression model, in which it is considered to vary with the strain and strain rates. A fracture criterion is also proposed in a low stress triaxiality range from 0.04 to 0.369. Error analysis for the modified JC model indicates that the model exhibits higher accuracy than the original one in predicting the flow stress at different strain rates. The fractography analysis indicates that the material has a typical ductile fracture mechanism including the shear fracture under pure shear and the dimple fracture under uniaxial tensile.

FEM Simulation on Uniaxial Tension of Hyperelastic Elastomers

2014 ◽  
Vol 659 ◽  
pp. 57-62 ◽  
Author(s):  
Vlad Carlescu ◽  
Gheorghe Prisacaru ◽  
Dumitru Olaru
Keyword(s):  
Experimental Data ◽  
Uniaxial Tension ◽  
Smart Materials ◽  
Model Simulation ◽  
Fem Simulation ◽  
Tensile Tests ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Good Correspondence

Modeling large nonlinear elastic deformation of elastomers is an important issue for developing new materials. Particularly, this is very promising for design and performance analysis of dielectric elastomers (DEs). These “smart materials” are capable of responding to an external electric field by displaying significant change in shape and size. In this paper, finite element method (FEM) was used to simulate the mechanical behavior of soft elastomers on uniaxial tension. Experimental data from uniaxial tensile tests were used in order to calibrate hyperelastic constitutive models of the material behavior. The constitutive model parameters were evaluated in ABAQUS/CAE. The 3D-model simulation results of a dumbbell shaped specimen at uniaxial tension shows very good correspondence with experimental data.

scholarly journals A New Viscosity Constitutive Model for Generalized Newtonian Fluids Using Theory of Micropolar Continuum

2020 ◽  
pp. 120-134
Author(s):  
Muhammad Sabeel Khan
Keyword(s):  
Constitutive Model ◽  
Flow Behavior ◽  
Constitutive Relations ◽  
Shear Thickening ◽  
Blood Rheology ◽  
Newtonian Fluids ◽  
Model Parameters ◽  
Micropolar Continuum ◽  
Generalized Newtonian Fluids ◽  
Contour Plots

In this paper, a new viscosity constitutive relation for the analysis of generalized Newtonian fluids is presented and analyzed. The theory of micropolar continuum is considered for the derivation of constitutive relations where the kinematics at the macroscopic level leads to incorporate the micro-rotational effects in existing rheology of Carreau Yasuda model. It provides a more realistic approach to analyze the flow behavior of generalized Newtonian fluids. To the best of author’s knowledge such generalization of the existing rheology of Carreau-Yasuda is not present in literature. In order to show the effects of micro-rotations on the viscosity of generalized fluids, different computational experiments are performed using finite volume method (FVM). The method is implemented and validated for accuracy by comparison with existing literature in the limiting case through graphs and tables and a good agreement is achieved. It is observed that with the increase of micro-rotations the shear thinning phenomena slower down whereas the shear thickening is enhanced. Moreover, the effects of various model parameters on horizontal and vertical velocities as well as on boundary layer thickness are shown through graphs and contour plots It is worth mentioning that the proposed constitutive model can be utilized to analyze the generalized Newtonian fluids and has wider applications in blood rheology.

scholarly journals New Constitutive Model for the Size Effect on Flow Stress Based on the Energy Conservation Law

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2617
Author(s):  
Chuanjie Wang ◽  
Haiyang Wang ◽  
Gang Chen ◽  
Qiang Zhu ◽  
Lingjiang Cui ◽  
...  
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Energy Conservation ◽  
Size Effect ◽  
Conservation Law ◽  
Prediction Accuracy ◽  
Energy Input ◽  
Uniaxial Tensile ◽  
New Model ◽  
Energy Conservation Law

In this study, a new model involving energy is established to characterize the size effect on flow stress. The new model treats the experimental machine and the specimen as an isolated system, and this isolated system satisfies the Energy Conservation Law. The total work performed on the specimen by the experimental machine is nearly equal to the energy consumed by the specimen plastic deformation and the energy consumed by friction (which can be ignored when working without friction). The new model predicts the energy consumption of the specimen deformation by quantifying the total energy input to the specimen by the experimental machine and then obtaining the relevant parameters of the constitutive model. Through uniaxial tensile tests of pure nickel thin sheets with various thickness/average grain sizes (t/d), the new model was used to optimize the parameters of the existing constitutive model that predicts the flow stress of specimens with different t/d. The prediction accuracy of the optimized constitutive model is improved, especially for specimens with a t/d < 1. The new model is established from the perspective of energy input to avoid the analysis of the material deformation mechanism and improve the prediction accuracy.

Sign in / Sign up

Export Citation Format

Share Document