Evolutional Friction Law in the Numerical Simulation of the Deep Drawing of a Rail

2006 ◽  
Vol 514-516 ◽  
pp. 1443-1447
Author(s):  
Marta C. Oliveira ◽  
J. Luís Alves ◽  
Luís Filipe Menezes
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Friction Coefficient ◽  
Deep Drawing ◽  
Kinematic Hardening ◽  
Friction Forces ◽  
Friction Law ◽  
Entire Process ◽  
Constant Friction ◽  
Blank Sheet

One of the most relevant technological parameters for the accurate numerical simulation of the deep drawing process is friction, since the contact between the blank sheet and tools develops friction forces that act as supplementary boundary conditions that determine the final part shape. Most applications reported in literature are still restricted to Coulomb’s law with a constant friction coefficient over the entire process. Although it is consensual that state conditions of contact surfaces and consequently the friction behaviour are influenced by a large number of parameters, there is no agreement about a wide-ranging law to accurately describe the friction evolution. One possibility is to use phenomenological laws that accurately fit experimental data. A Voce type law is used in this work to describe the evolution of the friction coefficient over the entire process as function of the contact pressure. This type of law guarantees a good correlation with experimental data and also numerical stability. The Voce type law was implemented in the static implicit code DD3IMP. The analysis of the relevance of considering the evolutional friction law in the numerical simulation is performed for a U-rail. This shape was selected for this study due to the simple deformation mechanisms that are involved, but also because it is a rail specially conceived to emphasize 2-D springback defects. The blank sheet material selected is a 6016-T4 aluminium alloy. The plastic behaviour is modelled using the 1948 Hill’s criterion with isotropic and kinematic hardening. The numerical results obtained considering the evolutional friction law are compared with two other results obtained with: (i) a constant friction value of 0.10, normally used for this material in industrial practice and (ii) three constant friction coefficients for each contact zone (flat, die radius and punch radius).

Numerical Simulation of Deep-Drawing Processes of Square Cup under Bilateral Constrained Conditions

2011 ◽  
Vol 189-193 ◽  
pp. 2892-2896 ◽  
Author(s):  
Xiao Ting Xiao ◽  
Li Cheng Huang ◽  
Yi Juan Liao ◽  
Li Guang Tan ◽  
Qiao Yu Chen
Keyword(s):  
Numerical Simulation ◽  
Friction Coefficient ◽  
Deep Drawing ◽  
Material Flow ◽  
Flow Rule ◽  
Blank Holder Force ◽  
Analysis Software ◽  
Blank Holder ◽  
Advanced Analysis ◽  
Constrained Conditions

In this paper, the flow rule of metal during the deep drawing of the non-symmetry workpieces was investigated by means of the numerical simulation of deep-drawing processes of square cup under bilateral constrained conditions. The numerical simulation was carried out by advanced analysis software Dynaform5.5. SUS304 stainless steel was used as the deforming materials. The influence of different friction coefficient and blank holder force on the drawing forming quality was analyzed. The results showed that the material flow in different areas has different trends with increase of friction coefficient and blank holder force.

scholarly journals NUMERICAL MODEL OF A LOCAL CONTACT OF A POLYMER NANOCOMPOSITE AND ITS EXPERIMENTAL VALIDATION

2021 ◽  
Vol 19 (1) ◽  
pp. 079
Author(s):  
Andrey I. Dmitriev
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Friction Coefficient ◽  
Experimental Validation ◽  
Polymer Nanocomposite ◽  
Characteristic Size ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Low Friction ◽  
Local Contact

In the paper a model of a local contact of a polymer-based nanocomposite was developed within the method of a movable cellular automaton. The features of mechanical behavior of nanocomposite at the mesoscale level under dry sliding were studied with explicit account for the microprofile of the counterbody surface and the characteristic sizes of nanofiller. Factors that contribute to the conditions for the formation of a stable tribofilm of silica nanoparticles are analyzed. Two other parameters like sample geometry and the value of relative sliding velocity are also examined. It is shown that the thickness of tribofilm depends on stress conditions at the contact, and the friction coefficient decreases with increasing sliding velocity similar to one observed experimentally. To ensure the low friction properties of polymer nanocomposite, particles whose sizes are comparable with the characteristic size of the substrate microprofile are preferred. Results of numerical simulation are in good correlation with available experimental data.

scholarly journals Influence of alternating bending on springback behavior of parts in deep drawing process with macro-structured tools

2018 ◽  
Vol 190 ◽  
pp. 14005 ◽  
Author(s):  
Ali Mousavi ◽  
Kevin Sven Ridolfi ◽  
Alexander Brosius
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Kinematic Hardening ◽  
Production Costs ◽  
Drawing Process ◽  
Friction Forces ◽  
Deep Drawing Process ◽  
Use Of Resources ◽  
Free Process ◽  
Alternating Bending

In today’s industry, waste prevention and an efficient use of resources are becoming more important due to economic and environmental requirements. Especially in forming processes such as deep drawing, a reduced use of lubricants is highly promising for saving resources and reducing production costs. Deep drawing with macro-structured tools is a novel approach to reduce the amount of friction forces and realize a lubricant free process. The induced alternating bending in sheet metal during the deep drawing process with macro-structured tools leads to an increase of its geometrical moment of inertia and consequently stabilizes the sheet against wrinkling. The induced alternating bending increases the back force in the sheet metal during the process and as a result affects the springback behaviour of the formed part. Furthermore, the resulted cyclic loading in flange area can leads to a kinematic hardening of some material. Within the scope of this paper, the influence of alternating bending on springback behaviour of parts in deep drawing process with macro-structured tools is studied. For this purpose, numerical simulations as well as experimental tests to form a U-channel with macro-structured tools are carried out.

Tribological Investigation of Deep-Drawing Processes Using Servo Presses

2012 ◽  
Author(s):  
Peter Groche ◽  
Norman Möller
Keyword(s):  
Friction Coefficient ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Fem Simulation ◽  
Process Window ◽  
Work Piece ◽  
Limiting Factor ◽  
Sliding Speed ◽  
Friction Forces ◽  
Process Speed

Deep-drawing is one of the most important processes for the economic production of sheet metal parts, especially for high quantities. The forming forces during the process are a limiting factor for the producible shapes. A particular importance is associated with the tribology, because the percentage of friction forces on the total forces is relatively high. The friction between sheet metal and tool is influenced by several factors, such as surface characteristics of the work piece and the tool, lubrication conditions and process parameters, like the contact pressure and the sliding speed. Controlling these parameters will expand the process window for deep-drawing. Lately, servo presses provide the possibility of controlling the process speed in dependency of the process progress. The subject of this paper is the tribological investigation of deep-drawing processes. The friction coefficient decreases with an increasing sliding speed. Investigating this correlation and utilizing it for the application with modern servo technology for industrial use is the main objective of the presented research works. First of all the dependency of the friction coefficient on the sliding speed is investigated by the use of the strip drawing tests, which allows the control of every parameter independently. The dependencies are implemented in a FEM-simulation, evaluating the potential for real deep-drawing processes. Deep-drawing experiments are then used to validate the results of the simulation with a speed-dependent friction coefficient as well as for the verification of the force reduction due to the influencing of process speed. In the end, the numerical simulated results in comparisons to the experimental measured results are discussed.

Optimization Parametric Study of Deep Drawing Process for a Standardized Cranial Implant

2011 ◽  
Vol 335-336 ◽  
pp. 813-817
Author(s):  
Khemajit Sena ◽  
Surasith Piyasin
Keyword(s):  
Friction Coefficient ◽  
Deep Drawing ◽  
Fe Simulation ◽  
Sheet Thickness ◽  
Optimization Procedure ◽  
Optimal Process ◽  
Drawing System ◽  
Blank Sheet ◽  
Input Parameters ◽  
Cranial Implant

The purpose of this study is to investigate the optimal process parameters use to fabricated a standardized cranial implant using deep drawing with a titanium mesh sheet. First, the mold for deep drawing, consisting of die, punch, blankholder and blank sheet, was designed within a CAD program. Then the formability of the mold was simulated using FE software. Furthermore, a link between the result of the FE simulation and CAE program was established to determine the best input parameters in the deep drawing system which produced minimal defects (wrinkles and ruptures). The parameters of interest in this study were the overall friction coefficient, blankholder friction coefficient, blankholder force and blank sheet thickness. The results showed the high feasibility of the joint CAE program and optimization procedure to calculate the best input parameters which can reduce time and cost consuming physical tryouts.

Simulated Analysis of Flow and Deformation in Trilateral Constrained and Asymmetric Square Cup Deep-Drawing

2011 ◽  
Vol 199-200 ◽  
pp. 1901-1905
Author(s):  
Li Cheng Huang ◽  
Xiao Ting Xiao ◽  
Li Guang Tan ◽  
Guo Liang Li
Keyword(s):  
Numerical Simulation ◽  
Stainless Steel ◽  
Friction Coefficient ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Forming Quality ◽  
Simulated Analysis

To satisfy the local forming need of sheet-metal part, numerical simulation of SUS304 stainless steel deep-drawing with trilateral constrained slot were carried out by employing the analytical software ETA/dynaform5.5. The influence of different friction coefficient and holder force on the forming quality was analyzed by taking the inflow volume while parts forming 50mm as standard. The results show that the effect of trilateral constraint on the uneven flow and deformation of flange. And some measures were illustrated to improve the quality of some of these parts.

scholarly journals Fibre-induced drag reduction

2008 ◽  
Vol 602 ◽  
pp. 209-218 ◽  
Author(s):  
J. J. J. GILLISSEN ◽  
B. J. BOERSMA ◽  
P. H. MORTENSEN ◽  
H. I. ANDERSSON
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Drag Reduction ◽  
Elastic Layer ◽  
Turbulent Drag Reduction ◽  
Rigid Polymer ◽  
Fibre Concentration ◽  
Induced Drag ◽  
Turbulent Drag

We use direct numerical simulation to study turbulent drag reduction by rigid polymer additives, referred to as fibres. The simulations agree with experimental data from the literature in terms of friction factor dependence on Reynolds number and fibre concentration. An expression for drag reduction is derived by adopting the concept of the elastic layer.

Multi-Step Forward Finite Element Method for the Numerical Simulation of Sheet Metal Forming

2011 ◽  
Vol 474-476 ◽  
pp. 251-254
Author(s):  
Jian Jun Wu ◽  
Wei Liu ◽  
Yu Jing Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Mapping Method ◽  
Constitutive Relationship ◽  
Element Method

The multi-step forward finite element method is presented for the numerical simulation of multi-step sheet metal forming. The traditional constitutive relationship is modified according to the multi-step forming processes, and double spreading plane based mapping method is used to obtain the initial solutions of the intermediate configurations. To verify the multi-step forward FEM, the two-step simulation of a stepped box deep-drawing part is carried out as it is in the experiment. The comparison with the results of the incremental FEM and test shows that the multi-step forward FEM is efficient for the numerical simulation of multi-step sheet metal forming processes.

Sign in / Sign up

Export Citation Format

Share Document