Surface Evolution and Lubricant Distribution in Deep Drawing

2013 ◽  
Vol 554-557 ◽  
pp. 811-824 ◽  
Author(s):  
Manuel Ludwig ◽  
Sebastian Volk ◽  
Peter Groche
Keyword(s):  
Surface Topography ◽  
Deep Drawing ◽  
Great Influence ◽  
Normal Pressure ◽  
The Finite Element Method ◽  
Friction Behavior ◽  
Surface Evolution ◽  
Inhomogeneous Character ◽  
Lubricant Distribution ◽  
Hydrodynamic Effects

Deep drawing is one of the most important processes applied in industrial production. Here the Finite-Element-Method (FEM) is an important tool in the development and optimization process. One aspect to optimize simulations is to consider real friction behavior. Thus the friction phenomenon has to be describable. In addition to contact normal pressure and velocity the surface topography and the lubricant amount have a great influence on friction. This paper illustrates the influence of surface evolution in real, inhomogeneous processes on the lubricant distribution. For this a rectangular cup with four different corner radii is used to evaluate local surface topographies and lubricant amounts in deep drawing. The lubricant amount is measured by fluorescence technique and the surface topography is evaluated by a confocal white-light microscope. Due to hydrodynamic effects the lubricant is squeezed out and displaced to adjacent regions. Further hydrostatic pressures built up in closed lubricant pockets force the lubricant to stay in the forming zone to bear a part of the load. In free forming zones without contact between the sheet and tool the surface roughens due to grain dislocations in the microstructure. This paper also presents the results of lubricant distribution and surface evolution by varying the initial lubricant amounts and drawing depth. It can be recognized that the different corner radii of the rectangle cup have a great influence on the surface evolution and lubricant distribution. Moreover it can be clearly seen that surface parameters correlate with the lubricant amount. By means of the described evaluation it is also possible to correlate these values with load histories consisting of contact pressures and strain evolution, evaluated in FEM. All the results contribute to a better understanding of the friction behavior in deep drawing and point out the inhomogeneous character of friction.

Influence of Geometrical Parameters on the Maximum Deep Drawing Height of Rectangular Parts

2014 ◽  
Author(s):  
Aarón Rivas Menchi ◽  
Hugo I. Medellín Castillo ◽  
Dirk F. de Lange ◽  
Pedro de J. García Zugasti
Keyword(s):  
Deep Drawing ◽  
Great Influence ◽  
Sheet Thickness ◽  
Geometrical Parameters ◽  
Drawing Process ◽  
The Finite Element Method ◽  
Cylindrical Parts ◽  
High Production ◽  
Cylindrical Cup

The deep drawing process is commonly used in the industry because its ability to produce parts with reduced weight and good mechanical properties at a high production rates. However, the elasto-plastic deformation mechanism of deep drawing is complex and difficult to analyse; this because there are many process parameters and variables involved that affect the quality of final products. Among these variables are the geometric parameters, which have been proved to have a great influence on the process. Theoretical and experimental analyses reported in the literature have been mainly focused on conventional cylindrical cup deep drawing. Few research works have dealt with the deep drawing analysis of non-cylindrical parts, particularly the influence of geometrical parameters on the deep drawing performance. This paper presents an analysis of the effect of geometrical parameters on the allowable deep drawing height (DDH) of rectangular parts before fracture. The aim is to identify the influence of the main geometrical parameters on the DDH, Numerical analyses based on the Finite Element Method (FEM) were used to investigate the influence of geometrical parameters, such as the radii, the metal sheet thickness, and the aspect ratio, among others, on the DDH.

Numerical Investigation of Size Effect on Dry Friction Behavior in Micro Upsetting Process

2014 ◽  
Vol 997 ◽  
pp. 321-324
Author(s):  
Wei Zheng ◽  
Guang Chun Wang ◽  
Bing Tao Tang ◽  
Xiao Juan Lin ◽  
Yan Zhi Sun
Keyword(s):  
Friction Coefficient ◽  
Size Effect ◽  
Dry Friction ◽  
Normal Pressure ◽  
Friction Model ◽  
Strain Hardening Exponent ◽  
Forming Process ◽  
Friction Behavior ◽  
Initial Yield Stress ◽  
Coulomb’S Friction

After modifying the Wahime/Bay friction model, a new friction model suitable for micro-forming process without lubrication is established. In this model, it is shows that the friction coefficient is a function of strain hardening exponent, the normal pressure and the initial yield stress of material. Based on the experimental data, the micro-upsetting process is simulated using the proposed friction model. The simulation results are used to investigate the size effect on the dry friction behavior. It is found that the Coulomb’s friction coefficient is dropping with miniaturization of specimens when the amount of reduction is not too large.

scholarly journals Study on the Damping Effect of Particle Dampers considering Different Surface Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaowei Li ◽  
Yue Yang ◽  
Weixing Shi
Keyword(s):  
Energy Dissipation ◽  
Surface Property ◽  
Material Selection ◽  
Great Influence ◽  
Contact Theory ◽  
Theoretic Model ◽  
The Finite Element Method ◽  
Particle Damping ◽  
Vibration Experiment ◽  
Particle Dampers

Particle dampers are nonlinear vibration control devices. The surface property has a great influence on the performance of the particle damper, but it is difficult to be considered and analyzed. This paper firstly gives a view of how to establish a theoretic model of the particle damper. The dynamic equation and energy dissipation coefficient of collision are revised from the Hertz contact theory in the proposed theoretic model, considering the friction of particles. Then, a contrastive collision model relying on the finite element method is established to verify the reasonability of the theoretic model. The effects of different factors which will have an influence on the performance of the particle damper are discussed, and several conclusions on how to optimize the particle damper are proposed. Except for the aforementioned dynamic analysis, this paper also presents a particle damping index to evaluate the capability of energy dissipation of different materials, in order to facilitate the material selection in the practical design. Finally, an experiment is developed to verify the character of the collision and energy dissipation. The feasibility of the proposed method to estimate the surface property of different particles is validated by the free vibration experiment.

Ti3AlC2 — A Soft Ceramic Exhibiting Low Friction Coefficient

2005 ◽  
Vol 475-479 ◽  
pp. 1251-1254 ◽  
Author(s):  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Zhi Li Zhang ◽  
Shi Bo Li ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Surface ◽  
High Speed ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Aluminum Carbide ◽  
Low Carbon ◽  
Friction Behavior ◽  
Sliding Speed ◽  
Al And Fe Oxides

The friction behavior of a high-purity bulk titanium aluminum carbide (Ti3AlC2) material dryly sliding against low carbon steel was investigated. Tests were performed using a block-on-disk type high-speed friction tester under sliding speed of 20 m/s and 60 m/s, several normal pressures from 0.1 to 0.8 MPa. The results showed that the friction coefficient is as low as about 0.18 for sliding speed of 20 m/s and only 0.1 for 60 m/s, and that almost not changes with the normal pressure. The reason could be related with the presence of a surface layer on the friction surface. The layer was analyzed to consist of Ti, Al and Fe oxides, which played a lubricate part inducing the friction coefficient decrease on the friction surface.

Off-Line Testing of Tribo-Systems for Sheet Metal Forming Production

2014 ◽  
Vol 966-967 ◽  
pp. 3-20 ◽  
Author(s):  
Niels Bay ◽  
Ermanno Ceron
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Normal Pressure ◽  
Environmentally Benign ◽  
Interface Pressure ◽  
Test Conditions ◽  
Interface Contact ◽  
Very High

Off-line testing of new tribo-systems for sheet metal forming production is an important issue, when new, environmentally benign lubricants are to be introduced. To obtain useful results it is, however, vital to ensure similar conditions as in the production process regarding the main tribo-parameters, which are tool/workpiece normal pressure, sliding length, sliding speed and interface contact temperature. The paper describes a generic methodology for such tests exemplified on an industrial, multistage deep drawing example, where deep drawing is followed by two successive re-drawing operations leading to very high tool/workpiece interface pressure and temperature in the second re-draw. Under such conditions only the best lubricant systems work satisfactory, and the paper shows how the performance of different tribo-systems in production may be predicted by off-line testing combined with numerical modelling in order to ensure proper test conditions.

scholarly journals The analysis of the parameters for deep drawing of cylindrical parts

2018 ◽  
Vol 178 ◽  
pp. 02011
Author(s):  
Dan Chiorescu ◽  
Esmeralda Chiorescu ◽  
Sergiu Olaru
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Forming Process ◽  
Thin Steel ◽  
Metal Forming Process ◽  
Cylindrical Parts ◽  
Cylindrical Cup ◽  
High Degree

Deep drawing is a very important metal forming process. Thin steel sheet is important material for manufacture of numerous products with deep drawing and stamping. Cold working provides also the possibility of making parts of various shapes, from the simplest to those with a high degree of complexity whose execution through other methods is uneconomical, difficult and sometimes even impossible. In this paper it is analyzed both experimentally and with the help of the finite element, the behavior of the blank during the cylindrical cup deep drawing process, using the ANSYS software program and the finite element method. A comparison is realized between the experimental and the analytical results, elaborating a representative set of problems that analyze the variation of the die punch clearance, movement of the punch and with or without lubrication. The results of the research are useful in developing a sensible design of experiments.

Evolution of Matt Surface Topography in Aluminium Pack Rolling

2005 ◽  
Author(s):  
Hiroshi Utsunomiya ◽  
Michael P. F. Sutcliffe ◽  
Hugh R. Shercliff ◽  
Pete S. Bate ◽  
Dan B. Miller
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Surface Topography ◽  
Material Properties ◽  
Quantitative Agreement ◽  
Aluminium Foil ◽  
The Finite Element Method ◽  
Good Quantitative Agreement ◽  
Pack Rolling ◽  
Element Method

Roughening of the matt surface of pack rolled aluminium foil has been modelled. The model is based on the finite element method using isotropic plasticity. A distribution in material properties has been used to simulate the distribution of orientations through the material. The predictions of roughness show good quantitative agreement with the experiments.

FE Analysis of Sif of Interfacial Crack Emanating from a Circular Notch in Ceramic/Metal Bi-Materials

2012 ◽  
Vol 428 ◽  
pp. 121-126
Author(s):  
Djamel Ouinas ◽  
Mohamed Sahnoun ◽  
N. Benderdouche
Keyword(s):  
Stress Concentration ◽  
Great Influence ◽  
Interfacial Crack ◽  
Damage Mechanism ◽  
The Finite Element Method ◽  
Bonded Materials ◽  
Multilayered Systems ◽  
Stress Concentration Effect ◽  
Curved Interface ◽  
Circular Notch

Ceramic/metal bimaterials systems are increasingly used in industry owing to the synergetic association of opposite properties of the bonded materials. Discontinuity in these properties can result in crack initiation and stress concentration entailing the bimaterial system failure. A good understanding of damage mechanism at the metal/ceramic interface is crucial to the dimensioning of multilayered systems. In this work the finite element method is used to analyze the stress concentration effect in a linear interface and curved interface. The geometrical configuration of the interface has a great influence the stress concentration on distribution developed near or in the assembly interface. The effect of a circular notch on the behavior of an interfacial crack is highlighted. The results indicate that the interface generates normal and tangential stress concentration resondless of the assembly mechanical properties. The curved geometry of the interface strongly reduces stress concentration in comparison with the linear interface. The reduction is 90%.

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