scholarly journals An inverse analysis to identify the Johnson-Cook constitutive model parameters for cold wire drawing process

2020 ◽  
Vol 21 (5) ◽  
pp. 527
Author(s):  
Ashkan Mahmoud Aghdami ◽  
Behnam Davoodi
Keyword(s):  
Strain Rate ◽  
Objective Function ◽  
Inverse Analysis ◽  
Static Condition ◽  
Tensile Tests ◽  
Wire Drawing ◽  
Material Behavior ◽  
Model Parameters ◽  
Drawing Process ◽  
Cold Wire

Johnson-Cook constitutive equation was utilized to model the 10100 copper and AA 1100 aluminum wires at the cold wire drawing process. Initial Johnson cook parameters were determined through quasi-static tensile tests at different strain rates. Analytical and finite element with VUHARD subroutine solutions were implemented to calculate the drawing forces using the Johnson cook parameters. Wire drawing experiments were carried out at different drawing conditions with two areal reductions and four drawing speeds with the strain rate ranged from 37 s−1 to 115 s−1 and wire drawing forces were measured using a load cell connected to the drawing die. Results showed that the Johnson cook model with parameters determined from a quasi-static condition was not able to predict the material behavior at the wire drawing process with a moderate strain rate. In order to modify the initial JC parameters an inverse analysis approach was adopted. An objective function was defined based on analytical and experimental drawing forces differences with respect to JC parameters. Using the Newton–Raphson method, new JC parameters were identified by minimizing the objective function. Updated Johnson cook parameters showed much more correlation with experimental results.

Transferability of the Gurson Damage Model Parameters with Charpy and Tensile Tests with Different Constrain Level

2009 ◽  
Vol 65 ◽  
pp. 19-31
Author(s):  
Ruben Cuamatzi-Melendez ◽  
J.R. Yates
Keyword(s):  
Strain Rate ◽  
Damage Model ◽  
Rolling Direction ◽  
Fracture Initiation ◽  
Tensile Tests ◽  
Model Parameters ◽  
Gurson Model ◽  
Finite Element Program ◽  
Element Program ◽  
Gurson's Model

Little work has been published concerning the transferability of Gurson’s ductile damage model parameters in specimens tested at different strain rates and in the rolling direction of a Grade A ship plate steel. In order to investigate the transferability of the damage model parameters of Gurson’s model, tensile specimens with different constraint level and impact Charpy specimens were simulated to investigate the effect of the strain rate on the damage model parameters of Gurson model. The simulations were performed with the finite element program ABAQUS Explicit [1]. ABAQUS Explicit is ideally suited for the solution of complex nonlinear dynamic and quasi–static problems [2], especially those involving impact and other highly discontinuous events. ABAQUS Explicit supports not only stress–displacement analyses but also fully coupled transient dynamic temperature, displacement, acoustic and coupled acoustic–structural analyses. This makes the program very suitable for modelling fracture initiation and propagation. In ABAQUS Explicit, the element deletion technique is provided, so the damaged or dead elements are removed from the analysis once the failure criterion is locally reached. This simulates crack growth through the microstructure. It was found that the variation of the strain rate affects slightly the value of the damage model parameters of Gurson model.

A Simple Analogous Model for the Determination of Cyclic Plasticity Parameters of Thin Wires to Model Wire Drawing

2007 ◽  
Vol 129 (3) ◽  
pp. 488-495
Author(s):  
T. Schenk ◽  
T. Seifert ◽  
H. Brehm
Keyword(s):  
Tensile Tests ◽  
Wire Drawing ◽  
Cyclic Stress ◽  
Cyclic Plasticity ◽  
Integration Time ◽  
Model Parameters ◽  
Compression Tests ◽  
Thin Wires ◽  
Fe Simulations ◽  
Analogous Model

Cyclic stress-strain measurements have to be performed in order to determine the cyclic plasticity parameters of material models describing the Bauschinger effect. For thin wires, the performance of tensile tests is often not possible due to necking of the specimen on exceeding the yield stress, whereas compression tests are uncritical. This paper presents an approach to determine the cyclic plasticity parameters by performance of compression tests for wires before and after drawing. Here, a simple analogous model is used instead of finite-element (FE) simulations. This approach has been applied for two different integration time steps in order to evaluate their influence on the fit and the accuracy of the integration. It is shown that good accuracy can be obtained for the cyclic plasticity parameters. For FE simulations using larger integration time steps, large deviations have been noted. However, there the analogous model could also be adopted in order to find appropriate model parameters. In general, it is the intention of this paper to show that searching an analogous model can be a very time- and cost-saving task.

The Precise Determination of the Johnson–Cook Material and Damage Model Parameters and Mechanical Properties of an Aluminum 7068-T651 Alloy

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
B. Bal ◽  
K. K. Karaveli ◽  
B. Cetin ◽  
B. Gumus
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Physical Simulation ◽  
Damage Model ◽  
Rolling Direction ◽  
Stress Triaxiality ◽  
Material Model ◽  
Tensile Tests ◽  
Model Parameters ◽  
Element Analysis

Al 7068-T651 alloy is one of the recently developed materials used mostly in the defense industry due to its high strength, toughness, and low weight compared to steels. The aim of this study is to identify the Johnson–Cook (J–C) material model parameters, the accurate Johnson–Cook (J–C) damage parameters, D1, D2, and D3 of the Al 7068-T651 alloy for finite element analysis-based simulation techniques, together with other damage parameters, D4 and D5. In order to determine D1, D2, and D3, tensile tests were conducted on notched and smooth specimens at medium strain rate, 100 s−1, and tests were repeated seven times to ensure the consistency of the results both in the rolling direction and perpendicular to the rolling direction. To determine D4 and D5 further, tensile tests were conducted on specimens at high strain rate (102 s−1) and temperature (300 °C) by means of the Gleeble thermal–mechanical physical simulation system. The final areas of fractured specimens were calculated through optical microscopy. The effects of stress triaxiality factor, rolling direction, strain rate, and temperature on the mechanical properties of the Al 7068-T651 alloy were also investigated. Damage parameters were calculated via the Levenberg–Marquardt optimization method. From all the aforementioned experimental work, J–C material model parameters were determined. In this article, J–C damage model constants, based on maximum and minimum equivalent strain values, were also reported which can be utilized for the simulation of different applications.

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 ANALYSIS OF THE SENSITIVITY OF VISCOELASTIC PARAMETERS AT THE STRAIN-RATE OF A THERMOPLASTIC

2019 ◽  
Author(s):  
Younès Saadallah ◽  
Semcheddine Derfouf ◽  
Belhi Guerira
Keyword(s):  
Strain Rate ◽  
Mathematical Formulation ◽  
Tensile Tests ◽  
Polyamide 6 ◽  
Model Parameters ◽  
Behavior Model ◽  
Strain Rates ◽  
Exponential Regression ◽  
Viscoelastic Parameters ◽  
The Subject

The behavior of thermoplastics depends on several factors, mainly time and temperature. The present work is the subject of a study of the dependence of these materials on time. The material considered in this study is a polyamide 6. The applied behavior model is represented by the Kelvin-Voigt viscoelastic mechanism with instant elasticity. Following the mathematical formulation of the equations of the model, tensile tests at different strain rates are conducted. The model parameters are then identified. These being sensitive to the strain-rate, the relation which links them with it is established by means of an exponential regression. The experimental results and those obtained by the model are presented, compared and interpreted. Their relevance and coherence validates both the model and the approach adopted.

scholarly journals Machine Learning Enhanced Dynamic Response Modelling of Superelastic Shape Memory Alloy Wires

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 304
Author(s):  
Niklas Lenzen ◽  
Okyay Altay
Keyword(s):  
Machine Learning ◽  
Shape Memory Alloy ◽  
Strain Rate ◽  
Shape Memory ◽  
Thermodynamic Parameters ◽  
Expert Knowledge ◽  
Material Behavior ◽  
Model Parameters ◽  
Engineering Structures ◽  
Wide Range

Superelastic shape memory alloy (SMA) wires exhibit superb hysteretic energy dissipation and deformation capabilities. Therefore, they are increasingly used for the vibration control of civil engineering structures. The efficient design of SMA-based control devices requires accurate material models. However, the thermodynamically coupled SMA behavior is highly sensitive to strain rate. For an accurate modelling of the material behavior, a wide range of parameters needs to be determined by experiments, where the identification of thermodynamic parameters is particularly challenging due to required technical instruments and expert knowledge. For an efficient identification of thermodynamic parameters, this study proposes a machine-learning-based approach, which was specifically designed considering the dynamic SMA behavior. For this purpose, a feedforward artificial neural network (ANN) architecture was developed. For the generation of training data, a macroscopic constitutive SMA model was adapted considering strain rate effects. After training, the ANN can identify the searched model parameters from cyclic tensile stress–strain tests. The proposed approach is applied on superelastic SMA wires and validated by experiments.

Bilinear damage evolution in AA2011 wire drawing processes

2022 ◽  
pp. 105678952110725
Author(s):  
Álvaro A González ◽  
Marcela A Cruchaga ◽  
Diego J Celentano
Keyword(s):  
Material Characterization ◽  
Damage Evolution ◽  
Mechanical Response ◽  
Tensile Tests ◽  
Wire Drawing ◽  
Drawing Process ◽  
Effective Plastic Strain ◽  
Predictive Capability ◽  
Two Parameters ◽  
Good Agreement

This paper presents an experimental and numerical analysis of damage evolution in AA2011 aluminum alloy wires drawn under different scenarios. To this end, load-unload tensile tests were firstly carried out in order to characterize the degradation of the mechanical response in every cycle where the experimental results show a bilinear damage relationship in terms of the effective plastic strain. Therefore, a modification of the classical Lemaitre model is proposed in this work in order to reproduce bilinear paths of damage with the addition of only two parameters that can be directly obtained from the material characterization. Then, the damage predictive capability of this new experimental-based model is assessed in numerical simulations of the drawing process in one and two passes (considering for this last case the sequential and tandem configurations) where the computed predictions are compared with the corresponding experimental data showing a good agreement between them.

Physical and Numerical Modelling of Wire Drawing Process of Mg Alloys in Heated Dies Accounting for Recrystallization

2014 ◽  
Vol 622-623 ◽  
pp. 651-658 ◽  
Author(s):  
Andrij Milenin ◽  
Piotr Kustra ◽  
Maciej Pietrzyk
Keyword(s):  
Mathematical Model ◽  
Tensile Tests ◽  
Wire Drawing ◽  
Complex Model ◽  
Mg Alloys ◽  
Drawing Process ◽  
Fracture Models ◽  
Body Production ◽  
Thermal Phenomena ◽  
Bio Compatibility

Magnesium-calcium alloys with increased bio-compatibility are applied in medicine for sake of high compatibility and solubility in human body. Production of surgical threads to integration of tissue may be one of the applications of those types of alloys. A new manufacturing process of thin wires made of biocompatible Mg alloys, including drawing in heated dies, was developed in Authors previous works. Conducting drawing process in conditions, in which recrystallization occurs, is the basis of the process. This allows for multi-pass drawing without intermediate annealing. Control of recrystallization after every pass using experimental method is complex so numerical simulation seems to be a rational method to design the process parameters. The purpose of the paper is developing a mathematical model of recrystallization for MgCa08 alloy, its implementation into the finite element (FE) code that simulates wire drawing and experimental verification of the numerical calculations. The first part of work was focused on the development of mathematical model of wire drawing process of Mg alloys in heated die. Proposed model takes into account thermal phenomena in the wire and in the die, plastic flow of the material, stress-strain state and recrystallization. The fracture criterion was implemented into FE code to eliminate the possibility of damage. The second part of the work was focused on experiments including upsetting and tensile tests for calibration of recrystallization and fracture models. Recrystallization model was calibrated on the basis of flow curves only what is a limitation. Therefore, experimental wire drawing on drawing bench developed by the Authors was the final stage of the work performed to validate the model. Recrystallization during wire drawing was studied. The developed computer program enables prediction of the recrystallization kinetics during wire drawing in heated die for MgCa08 alloy. The model of static and dynamic recrystallization of this alloy and complex model of the drawing process were proposed in this work, as well.

Evaluation of Bodner-Partom Model Parameters at High Strain Rate

1986 ◽  
Vol 108 (1) ◽  
pp. 75-80 ◽  
Author(s):  
A. M. Rajendran ◽  
S. J. Bless ◽  
D. S. Dawicke
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Material Behavior ◽  
Model Parameters ◽  
Plate Impact ◽  
Plane Plate ◽  
Wide Range ◽  
Split Hopkinson ◽  
Stress States

The objective of this paper is to model the high strain rate material behavior of metals using Bodner-Partom visco-plastic constitutive model. A unique algorithm has been developed to evaluate the model parameters from the split Hopkinson Bar and plane plate impact tests data. The model parameters were successfully determined for the 6061-T6 aluminum, 1020 steel, and HY 100 steel. Using the evaluated model parameters, the test data obtained from an unusually wide range of stress states for these three metals were successfully modeled.

Analysis of Nonisothermal Deep Drawing of Aluminum Alloy Sheet With Induced Anisotropy and Rate Sensitivity at Elevated Temperatures

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Kamyar Ghavam ◽  
Reza Bagheriasl ◽  
Michael J. Worswick
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Deep Drawing ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Alloy Sheet ◽  
Material Behavior ◽  
Aluminum Alloy Sheet ◽  
Rate Dependency ◽  
Strain Rate Dependency

In this paper, a finite element model is developed for 3000 series clad aluminum alloy brazing sheet to account for temperature and strain rate dependency, as well as plastic anisotropy. The current work considers a novel implementation of the Barlat YLD2000 yield surface in conjunction with the Bergstrom hardening model to accurately model aluminum alloy sheet during warm forming. The Barlat YLD2000 yield criterion is used to capture the anisotropy while the Bergstrom hardening rule predicts the temperature and strain rate dependency. The results are compared with those obtained from experiments. The measured stress–strain curves of the AA3003 aluminum alloy sheet at elevated temperatures and different strain rates are used to fit the Bergstrom parameters and measured R-values and directional yield stresses are used to fit the yield function parameters. Isothermal uniaxial tensile tests and nonisothermal deep drawing experiments are performed and the predicted response using the new constitutive model is compared with measured data. In simulations of tensile tests, the material behavior is predicted accurately by the numerical models. Also, the nonisothermal deep drawing simulations are able to predict the load–displacement response and strain distributions accurately.

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