Studies Concerning Numerical Prediction of Metal Fibering Obtained by Cold Bulk Forming Using Sensitivity Analysis of Tribological and Rheological Properties on a Cylindrical Crushing Process

2016 ◽  
Vol 841 ◽  
pp. 29-38
Author(s):  
Adinel Gavrus ◽  
Daniela Pintilie ◽  
Roxana Nedelcu
Keyword(s):  
Sensitivity Analysis ◽  
Constitutive Behavior ◽  
Rheological Equation ◽  
Metallic Material ◽  
High Importance ◽  
Friction Law ◽  
Bulk Forming ◽  
Cold Bulk ◽  
Abaqus Software ◽  
Softening Term

The present research paper concerns a numerical and experimental analysis of the tribologic and rheological constitutive behavior influence on prediction of metallic material forging fibering. Numerical analysis using finite element Forge® code and Abaqus software show the high importance of the friction law formulation and of the material rheological softening on the fibers morphology and on their position coordinates. Calibration and sensitivity of friction law together with the numerical sensitivity of the softening term corresponding to a Hansel-Spittel rheological equation have been studied for a cylindrical crushing test of a 16MnCr5 steel.

Effect of forming conditions on frictional characteristic in cold bulk forming process of copper alloy

2021 ◽  
Vol 155 ◽  
pp. 106786
Author(s):  
Da-Wei Zhang ◽  
Guang-Can Yang ◽  
Ze-Bang Zheng ◽  
Sheng-Dun Zhao
Keyword(s):  
Copper Alloy ◽  
Forming Process ◽  
Bulk Forming ◽  
Frictional Characteristic ◽  
Cold Bulk

Determination of a Dimensionless Equation for Shear Friction Factor in Cold Forging

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
K. H. Jung ◽  
Y. T. Im
Keyword(s):  
Friction Factor ◽  
Friction Model ◽  
Cold Forging ◽  
Practical Applications ◽  
Dimensionless Equation ◽  
Bulk Forming ◽  
Highly Nonlinear ◽  
Shear Friction ◽  
Shear Friction Factor ◽  
Cold Bulk

In cold bulk forming processes, a constant shear friction model is widely used to apply friction. However, it is not easy to predict the shear friction factor since frictional behavior is highly nonlinear and is dependent upon a number of processing variables, such as the hardness of the material, lubricity, sliding velocity, surface contact conditions, and the environment, etc. This paper presents a dimensionless equation that predicts the shear friction factor at the counter punch interface mfd that was empirically determined by dimensional analysis, using the tip test results available in the literature as a function of selected process variables, such as the yield strength and initial specimen's radius of the deforming material, hardness, and surface roughness of the deforming material and the counter punch, viscosity of the lubricant, and deformation speed. To verify the determined equation, a new set of experiments were carried out for specimens made of AL7075-O. The prediction of the shear friction factor at the punch interface was also achieved by simply dividing the dimensionless equation by the x ratio defined by x = mfd/mfp, which is dependent on the hardening exponent of the deforming material based on previous studies. The predicted mfd and mfp were found to be reasonable owing to comparisons with the experimental data obtained for AL7075–O in this study. These results will be beneficial in scientifically assessing the effect of the processing parameters on the friction, individually and economically selecting the lubrication condition for cold bulk forming for practical applications.

scholarly journals Use of Numerical Simulation at Optimisation of Technological Processes of Cold Bulk Forming

2012 ◽  
Vol 58 (1) ◽  
pp. 175-182
Author(s):  
Stanislav Rusz ◽  
Stanislav Tylšar ◽  
Jan Kedroň ◽  
Michal Salajka ◽  
Tomáš Brumar
Keyword(s):  
Numerical Simulation ◽  
Technological Processes ◽  
Bulk Forming ◽  
Cold Bulk

scholarly journals Determination of Magnitudes and Orientation of the Paleostress of Bekhme Structure in Shaqlawa area, Northerneastern Iraq

2021 ◽  
pp. 1204-1212
Author(s):  
Atheer E. K. AL- Hachem ◽  
Shatha Hassan
Keyword(s):  
Principal Stress ◽  
Arabian Plate ◽  
Tectonic Activity ◽  
High Importance ◽  
Friction Law ◽  
Tectonic Events ◽  
Active Tectonic ◽  
Vertical Thickness ◽  
Paleostress Analysis

This study presents the determination of the paleostress magnitudes and orientation of Bekhme Structure in Shaqlawa area, northeastern Iraq. Paleostress analysis of slip-fault measurements is performed using Right dihedral, Lisle diagram, and Mohr Circles methods. Depending on Mohr Circles, Bott law, and vertical thickness, the magnitudes of the paleostress at the time of the tectonic activity were determined. Firstly, Georient Software was used to estimate the orientation of the paleostresses (σ1, σ2, and σ3). Secondly, using the rupture –friction law, taking into account the depth of the overburden and the vertical stress (σv),the magnitudes of the paleostresses were calculated (σ1=4500 bars, σ2=1900 bars and σ3=700 bars).  The high magnitudes of the principal stress axes may be attributed to the active tectonic events which led to the deformation of the area during the Cretaceous and Tertiary periods. The study area shows that the poles of the measured faults lie in the reactivated area of Mohr circles. This indicates the instability of the study area.  The study area is estimated to have high importance, due to the possibility of the existence of deposited hydrocarbons. Fold- Thrust belt marks the deformation fronts of the major orogeny that forms from the collision of the Arabian Plate with the Turkish and Iranian Plates.                                           

Prediction of damage in cold bulk forming processes

PAMM ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 1037-1040 ◽  
Author(s):  
Maksim Zapara ◽  
Eva Augenstein ◽  
Dirk Helm
Keyword(s):  
Bulk Forming ◽  
Cold Bulk
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