Sensitivity Analysis of Hydro-Rim Deep Drawing of Cylindrical Cups

Manufacturing ◽  
2003 ◽  
Author(s):  
Jeries J. Abou-Hanna ◽  
Timothy McGreevy ◽  
Abdalla Elbella ◽  
Haithem Algousi
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Material Model ◽  
Chamber Pressure ◽  
Process Conditions ◽  
Plastic Behavior ◽  
Drawing Ratio ◽  
Real Time Control ◽  
Time Control ◽  
Punch Speed

Extensive nonlinear finite element analyses were conducted to help predict practical test conditions of intelligent hydro-rim deep forming of cylindrical cups under controlled cooled punch and heated blank temperatures, punch speed, chamber and rim pressures, and punch friction. The study focused on finding practical process conditions for maximizing the drawing ratio by variations in blank and punch temperatures, friction, rim pressure, chamber pressure, and punch speed. The study was based on an experimental cell that aimed at using real time control of the mentioned parameters to delay the necking process. The finite element material model considered the plastic behavior to be strain rate and temperature dependent. While conventional deep drawing is limited to a Limit Drawing Ratio (LDR) of about 2, the results show that a parameters listed above. Blank temperature, punch friction, rim pressure, and chamber pressure provide significant influence of various degrees on increasing the cup drawing ratio. Blank heating is very effective, but does not by itself guarantee higher LDR. The presence of punch friction coupled with chamber pressure tends to delay the necking and moves the latter up along the cup wall and away from the cup bottom corner. Rim pressure, while difficult to implement, results in significant improvement of the LDR, since it helps push the material into the die, and in doing so reduces the cup-wall tension that causes the material instability. High rim pressure, on the other hand, increases the blank thickness resulting in increased blank holder loads. Punch temperature does not play as critical a role as the blank temperature in maintaining a high LDR under the conditions investigated. The study revealed that punch speed had to be above a certain critical level for a LDR of 4. However, increased punch speed proved to cause higher variations in the thickness along cup wall. It is important to mention that the results of this study do not necessarily apply to all metals; copper material was used here. Metals with low ductility, for example would react differently, a subject of future studies.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

A New Flexible Rapid Thermal Processing System

1995 ◽  
Vol 389 ◽  
Author(s):  
K. C. Saraswat ◽  
Y. Chen ◽  
L. Degertekin ◽  
B. T. Khuri-Yakub
Keyword(s):  
Control System ◽  
Real Time ◽  
Processing System ◽  
Process Conditions ◽  
Temperature Uniformity ◽  
Real Time Control ◽  
Wafer Temperature ◽  
Time Control ◽  
Wide Range ◽  
Optical Flux

ABSTRACTA highly flexible Rapid Thermal Multiprocessing (RTM) reactor is described. This flexibility is the result of several new innovations: a lamp system, an acoustic thermometer and a real-time control system. The new lamp has been optimally designed through the use of a “virtual reactor” methodology to obtain the best possible wafer temperature uniformity. It consists of multiple concentric rings composed of light bulbs with horizontal filaments. Each ring is independently and dynamically controlled providing better control over the spatial and temporal optical flux profile resulting in excellent temperature uniformity over a wide range of process conditions. An acoustic thermometer non-invasively allows complete wafer temperature tomography under all process conditions - a critically important measurement never obtained before. For real-time equipment and process control a model based multivariable control system has been developed. Extensive integration of computers and related technology for specification, communication, execution, monitoring, control, and diagnosis demonstrates the programmability of the RTM.

Formability and Process Conditions of Magnesium Alloy Sheets

2005 ◽  
Vol 488-489 ◽  
pp. 453-456 ◽  
Author(s):  
Shi Hong Zhang ◽  
Yong Chao Xu ◽  
G. Palumbo ◽  
S. Pinto ◽  
Luigi Tricarico ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Tensile Tests ◽  
Process Conditions ◽  
Drawing Ratio ◽  
Temperature Range ◽  
Fine Grained ◽  
Axial Tensile ◽  
Die Surface ◽  
Lower Temperature Range ◽  
Lower Temperature

Comparing the formability with each other, extrusion and various rolling experiments were carried out to make fine-grained AZ31 Mg sheets, and uni-axial tensile tests were carried out at different strain rates and temperatures to investigate the effect of different variables. A warm deep drawing tool setup with heating elements, which were distributed under the die surface and inside the blank holder, was designed and manufactured, and deep drawing was performed. Extruded Mg alloy AZ31 sheets exhibit the best deep drawing ability when working in the temperature range 250-350°C. Extruded and rolled sheets of 0.8 mm thick were also deep drawn in the lower temperature range 105-170°C，showing good formability and reaching a Limit Drawing Ratio up to 2.6 at 170°C for rolled sheets. At last, a sheet cup 0.4 mm thick was deep drawn successfully at 170 °C.

scholarly journals Development technique for deep drawing without blank holder to produce circular cup of brass alloy

2015 ◽  
Vol 4 (1) ◽  
pp. 187 ◽  
Author(s):  
Ali Hassan Saleh ◽  
Ammer Khalaf Ali
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Deep Drawing ◽  
Cone Angle ◽  
Element Model ◽  
Drawing Ratio ◽  
Clearance Ratio ◽  
Blank Holder ◽  
Half Cone ◽  
Half Cone Angle

Of this technique compared to the conventional deep drawing is that the circular cup can be carried out in single action press with limit In this paper a new mechanism for deep drawing was proposed to produce circular cup from thin plate without blank holder. In this technique the die assembly includes punch, die and die-punch. A 2D axisymmetric finite element model was built using DEFORM software. Effect of die geometry (half- cone angle) on maximum load, thickness distribution, strain distribution and effect of clearance ratio between punch and (die-punch) on the wrinkling of the cup were investigated. Three half-cone angles of die (15o, 30o and 45o) were used for forming sheet metal of brass (CuZn37) which had initial thickness of (1mm) at four clearance ratio (c/t) for die of 30o half-cone angle. Finite element model results showed good agreement with experimental results. Die of 30o half-cone angle with clearance ratio (c/t) of 0.9 gave the best product without wrinkling. The main advantage drawing ratio (LDR) of 1.86 and blank diameter to blank thickness ratio (d/t) < 86.

Finite Element Modeling of Induction Heating on Easy-Open-End Dies

2013 ◽  
Vol 321-324 ◽  
pp. 881-885
Author(s):  
Gang Li ◽  
Jian Chen ◽  
Li Qiu Jin ◽  
Wei Wang ◽  
Cai Hui
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Induction Heating ◽  
Theoretical Foundation ◽  
Cylinder Surface ◽  
Thermal Coupling ◽  
Real Time Control ◽  
Element Modeling ◽  
Time Control ◽  
Simulation And Experiment

Through the magnetic-thermal coupling of ANSYS, the finite element modeling (FEM) of induction heating of the easy-open-end die was completed and the distribution of the dies temperature was determined. Simulation results showed that the dies cylinder surface temperature was high and close to the center was low with a small difference in temperature of about 3°C. Both simulation and experiment results demonstrated the benefits of using induction heating which could guarantee rapid and even heating. This result meant that the dies height varies evenly and was easy to be controlled. The results supplied a strong theoretical foundation for the project of real-time control easy-open-ends notch height.

Effect of temperature and punch speed on forming limit strains of AA5182 alloy in warm forming and improvement in failure prediction in finite element analysis

2017 ◽  
Vol 52 (4) ◽  
pp. 258-273 ◽  
Author(s):  
D Raja Satish ◽  
D Ravi Kumar ◽  
Marion Merklein
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Deep Drawing ◽  
Failure Prediction ◽  
Forming Limit ◽  
Element Analysis ◽  
Working Temperature ◽  
Warm Working ◽  
Punch Speed

Formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied. Forming limit strains of sheets of two different thicknesses have been determined experimentally in different modes of deformation (biaxial tension, plane strain and tension–compression) by varying temperature and punch speed. A correlation has been established for plane strain intercept of the forming limit diagram (FLD0) with temperature, punch speed and thickness from the experimental results. This correlation has been used to plot the forming limit diagrams for failure prediction in the finite element analysis of warm deep drawing of cylindrical cups. The effect of strain and strain rate on material flow behavior has been incorporated using a strain rate–sensitive power hardening law in which the strain hardening exponent and strain rate sensitivity index have been experimentally determined. The predictions from simulations have been validated by warm deep drawing experiments. Large improvement in accuracy of failure prediction has been observed using the FLDs plotted based on the developed correlation when compared to the existing method of calculating FLD0 using only strain hardening coefficient and thickness. The results clearly indicate the importance of incorporating temperature and punch speed in failure prediction of Al alloys using FLDs in the warm working temperature range.

On the Comparison of the Pseudo Rigid Body Model Method and the Finite Element Method for a 3DOF Planar Micro-Motion Stage

2000 ◽  
Author(s):  
J. Zou ◽  
L. G. Watson ◽  
W. J. Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compliant Mechanism ◽  
The Finite Element Method ◽  
Real Time Control ◽  
Body Model ◽  
Time Control ◽  
Rigid Body Model ◽  
Micro Motion ◽  
Element Method

Abstract This paper discusses one type of commonly used parallel manipulator mechanism for the generation of micro-motion. This mechanism is designed as a compliant mechanism. The design and control of such a compliant mechanism is an important issue. This paper focuses on kinematic issues with consideration of future real-time control of the system. In particular, a constant-Jacobian method to approximate the kinematics, which is based on a pseudo rigid body model of the compliant mechanism, is further validated. This validation is based on the difference between this approximate method and the finite element method to the actual device, for an actuator range of 0–15 μm. The computational time with this approximate method is nearly 50 times less than that with the finite element method. It is expected that this approximation method will be far superior to the finite element method in terms of real-time control.

scholarly journals Finite element analysis of deep drawing

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987456 ◽  
Author(s):  
Dyi-Cheng Chen ◽  
Li Cheng-Yu ◽  
Yu-Yu Lai
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Deep Drawing ◽  
Drawing Ratio ◽  
Element Analysis ◽  
Forming Mechanism ◽  
Analysis Process ◽  
Plastic Flow Stress

With the advancement of technology, aiming for achieving a greater lightness and smaller size of 3C products, parts processing technology not only needs to explore the basic scientific theory of materials but also needs to discuss the process of deep drawing numerical and the plastic deformation. This study is based on the square shape of the deep drawing numerical simulation, and aluminum alloy plastic flow stress was input into the finite element method for simulation of plastic deformation in the aluminum alloy friction, mold clamping force, and frequency, as well as amplitude in the influence of forming mechanism and the drawing ratio of aluminum alloy. Finite element analysis software has the function of grid automatic rebuild, which can rebuild the broken grid in the analysis into a complete grid shape, which can avoid the divergence caused by numerical calculation in the analysis process. The greater the obtained error value, the best plastic parameters can be found.

scholarly journals Model-Based Optimisation and Control Strategy for the Primary Drying Phase of a Lyophilisation Process

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 181 ◽  
Author(s):  
Brecht Vanbillemont ◽  
Niels Nicolaï ◽  
Laurens Leys ◽  
Thomas De Beer
Keyword(s):  
Real Time ◽  
Control Strategy ◽  
Freeze Drying ◽  
Fixed Time ◽  
Chamber Pressure ◽  
Interface Temperature ◽  
Real Time Control ◽  
Choked Flow ◽  
Model Based ◽  
Time Control

The standard operation of a batch freeze-dryer is protocol driven. All freeze-drying phases (i.e., freezing, primary and secondary drying) are programmed sequentially at fixed time points and within each phase critical process parameters (CPPs) are typically kept constant or linearly interpolated between two setpoints. This way of operating batch freeze-dryers is shown to be time consuming and inefficient. A model-based optimisation and real-time control strategy that includes model output uncertainty could help in accelerating the primary drying phase while controlling the risk of failure of the critical quality attributes (CQAs). In each iteration of the real-time control strategy, a design space is computed to select an optimal set of CPPs. The aim of the control strategy is to avoid product structure loss, which occurs when the sublimation interface temperature ( T i ) exceeds the the collapse temperature ( T c ) common during unexpected disturbances, while preventing the choked flow conditions leading to a loss of pressure control. The proposed methodology was experimentally verified when the chamber pressure and shelf fluid system were intentionally subjected to moderate process disturbances. Moreover, the end of the primary drying phase was predicted using both uncertainty analysis and a comparative pressure measurement technique. Both the prediction of T i and end of primary drying were in agreement with the experimental data. Hence, it was confirmed that the proposed real-time control strategy is capable of mitigating the effect of moderate disturbances during batch freeze-drying.

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