Material Behavior Modeling in Machining Simulation of 7075-T651 Aluminum Alloy

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Shuhui Li ◽  
Bo Hou
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Orthogonal Cutting ◽  
Material Behavior ◽  
Experimental Results ◽  
Machining Process ◽  
Dynamic Flow ◽  
Workpiece Material ◽  
Damage Criterion ◽  
Damage Initiation

Accurate modeling of workpiece material behavior in machining is critical to analyze and design a process. The workpiece material behavior in the machining process involves dynamic flow stress and damage/fracture behavior, which are very difficult to be determined. In this study, the extended split Hopkinson pressure bar (SHPB) test is conducted to determine the dynamic flow stress curves of 7075-T651 aluminum alloy, which enables the strain, strain rate and the temperature obtained in the test to approach that in the cutting condition. A damage criterion under the typical stress state of orthogonal cutting is established to reflect the material damage initiation in primary shear zone. The damage criterion parameters of 7075-T651 alloy are determined by comparing the numerical and experimental results of the proposed inner high-pressure piercing fracture test. The orthogonal cutting test and simulation of 7075-T651 alloy are conducted. It is demonstrated that the determined flow stress and the established damage criterion produces realistic process outputs in agreement with experimental results.

Identification of Process Damping Coefficient Based on Material Constitutive Property

2014 ◽  
Author(s):  
Xiaoliang Jin
Keyword(s):  
Energy Dissipation ◽  
Flank Wear ◽  
Orthogonal Cutting ◽  
Element Model ◽  
Machining Process ◽  
Damping Coefficient ◽  
Chatter Stability ◽  
Workpiece Material ◽  
Process Damping ◽  
Constitutive Property

The contact between the tool flank wear land and wavy surface of workpiece causes energy dissipation which influences the tool vibration and chatter stability during a dynamic machining process. The process damping coefficient is affected by cutting conditions and constitutive property of workpiece material. This paper presents a finite element model of dynamic orthogonal cutting process with tool round edge and flank wear land. The process damping coefficient is identified based on the energy dissipation principle. The simulated results are experimentally validated.

The Effect of Material Flow Stress on Analytical Simulation of Machining

2010 ◽  
Vol 29-32 ◽  
pp. 1809-1814
Author(s):  
Bing Lin Li ◽  
Ling Ling ◽  
Yu Jin Hu ◽  
Xue Lin Wang
Keyword(s):  
Flow Stress ◽  
Shear Zone ◽  
Analytical Model ◽  
Material Flow ◽  
Model Simulation ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Thermomechanical Model ◽  
Workpiece Material ◽  
Flow Stress Data

The flow stress data of the workpiece are extremely crucial for the cutting simulation. The study shows how the input data affect the analytical predictions of cutting force and temperature. The Johnson-Cook material model is used to represent workpiece flow stress in the primary shear zone. A thermomechanical model of orthogonal cutting is proposed based on the main shear plane divides the primary shear zone into two unequal parts. Five different sets of workpiece material flow stress data used in the Johnson-Cook’s constitutive equation are chosen and make the sensitivity analysis for analytical model. Simulation results were compared to orthogonal cutting test data from the available literature, and find the effects of flow stress on analytical model was different from that for finite element model.

scholarly journals Comparison of Flow Stress of Aluminum Alloy 6061-T6 Obtained From Chip Pulling Orthogonal Cutting and Kolsky Bar Testing

2020 ◽  
Vol 48 ◽  
pp. 579-585
Author(s):  
Changlong Cui ◽  
Pavan Bhavsar ◽  
Homar Lopez-Hawa ◽  
Vis Madhavan ◽  
Wilfredo Moscoso-Kingsley
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Orthogonal Cutting ◽  
Kolsky Bar ◽  
Aluminum Alloy 6061 ◽  
Alloy 6061

scholarly journals An Improved Johnson–Cook Constitutive Model and Its Experiment Validation on Cutting Force of ADC12 Aluminum Alloy During High-Speed Milling

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1038
Author(s):  
Xinxin Meng ◽  
Youxi Lin ◽  
Shaowei Mi
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Constitutive Model ◽  
Strain Rate ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Speed ◽  
Experimental Results ◽  
Element Analysis

Because of the massive work and high cost of milling experiments, finite element analysis technology (FEA) was used to analyze the milling process of ADC12 aluminum alloy. An improved Johnson–Cook (J–C) constitutive equation was fitted by a series of dynamic impact tests in different strain rates and temperatures. It found that the flow stress gradually increases as the strain rate rises, but it decreases as the test temperature rises. Compared with the J–C constitutive model, the predicted flow stress by the improved J–C constitutive model was closer to the experimental results when the strain rate was larger than 8000 s−1 and the temperature was higher than 300 °C. A two-dimensional cycloidal cutting simulation model was constructed based on the two J–C constitutive equations which was validated by milling experiments at different cutting speeds. The simulation results based on the improved J–C constitutive equation were closer to the experimental results and showed the cutting force first increased and then decreased, with cutting speed increasing, reaching a maximum at 600 m/min.

Effects of the Flow Stress in Finite Element Simulation of Machining Inconel 718 Alloy

2014 ◽  
Vol 611-612 ◽  
pp. 1210-1216 ◽  
Author(s):  
Farshid Jafarian ◽  
Mikel Imaz Ciaran ◽  
Pedro José Arrazola ◽  
Luigino Filice ◽  
Domenico Umbrello ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Inconel 718 ◽  
Orthogonal Cutting ◽  
Material Model ◽  
Material Behavior ◽  
Machining Process ◽  
Inconel 718 Alloy ◽  
Element Simulation ◽  
Inconel 718 Superalloy

Inconel 718 superalloy is one of the difficult-to-machine materials which is employed widely in aerospace industries because of its superior properties such as heat-resistance, high melting temperature, and maintenance of strength and hardness at high temperatures. Material behavior of the Inconel 718 is an important challenge during finite element simulation of the machining process because of the mentioned properties. In this regard, various constants for Johnson–Cook’s constitutive equation have been reported in the literature. Owing to the fact that simulation of machining process is very sensitive to the material model, in this study the effect of different flow stresses were investigated on outputs of the orthogonal cutting process of Inconel 718 alloy. For each model, the predicted results of cutting forces, chip geometry and temperature were compared with experimental results of the previous work at the different feed rates. After comparing the results of the different models, the most suitable Johnson–Cook’s material model was indentified. Obtained results showed that the selected material model can be used reliably for machining simulation of Inconel 718 superalloy.

Experimental and Physical-Based Constitutive Model Study of FCC Metal Over Wide Temperature and Strain Rate Ranges

2015 ◽  
Author(s):  
Jianchao Yu ◽  
Gang Wang ◽  
Jianwei Qin ◽  
Maobing Shuai ◽  
Yiming Rong
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
True Strain ◽  
Experimental Results ◽  
Deformation Behaviors ◽  
Fcc Metal

Dynamic deformation behaviors of aluminum alloy Al1060 (FCC metal) are studied by the uniaxial compression tests on the Split Hopkinson Pressure Bar over wide temperature and strain rate ranges. The experimental results show that the flow stress is both strain rate and temperature sensitivity. The flow stress decreases with increasing temperature when the strain rate keeps constant. When the temperature keeps constant, the flow stress increases with increasing strain rate. Considering the thermal activation of dislocation gliding in the dynamic deformation process, a physical-based constitutive model is developed based on the experimental results to predict the flows stress of Al1060 at a given strain rate and temperature. The material constants in the constitutive model are determined by the nonlinear genetic algorithm. The true stress-true strain curves predicted by the proposed constitutive models can give good correlations with the experimental results, which confirm that the proposed physical-based constitutive can accurately characterize the dynamic deformation behaviors of the studied aluminum alloy Al1060.

Identification of Machining Process Damping Using Output-Only Modal Analysis

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
K. Ahmadi ◽  
Y. Altintas
Keyword(s):  
Orthogonal Cutting ◽  
Machining Process ◽  
Damping Coefficient ◽  
Chatter Stability ◽  
Force Coefficient ◽  
Workpiece Material ◽  
Process Damping ◽  
Indentation Force ◽  
Output Only ◽  
Cutting Speeds

The existing chatter stability prediction algorithms fail in low-speed machining of difficult to cut alloys, unless process damping contributed by the tool flank face–finish surface contact is considered. This paper presents a new method in predicting the material dependent process damping coefficient from chatter free orthogonal cutting tests. An equivalent process damping coefficient of the dynamic system is estimated from the frequency domain decomposition (FDD) of the vibration signals measured during stable cutting tests. Subsequently, the specific indentation force of the workpiece material is identified from the process damping coefficients obtained over a range of cutting speeds. The specific indentation force coefficient is used in an explicit formula of process damping which considers the radius and clearance angle of the cutting edge. It is experimentally shown that when the proposed process damping model is included, the accuracy of chatter stability predictions in turning and milling improves significantly at low cutting speeds.

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