scholarly journals Investigation of Sheet Metal Forming Using a Rapid Compression Machine

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3957 ◽  
Author(s):  
Sandeep P. Patil ◽  
Yann Fenard ◽  
Shridhar Bailkeri ◽  
Karl Alexander Heufer ◽  
Bernd Markert
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Peak Pressure ◽  
Experimental Results ◽  
Maximum Height ◽  
Outer Diameter ◽  
Rapid Compression Machine ◽  
Damage Initiation ◽  
Rapid Compression

The primary goal of this work is to understand the deformation behavior of an aluminum alloy (Al) workpiece by using a rapid compression machine (RCM). The primary novelty in this work is that this is the first study on sheet metal forming using RCM. Numerical simulation and experimental results are in excellent agreement, e.g., the dome-shape, the maximum height, the final outer diameter, and the thickness distribution of the deformed workpiece. We demonstrate that the maximum deformation height grows linearly with the peak pressure with an intercept tending to zero. The proposed linear relationship can be effectively used for designing new components for a specific application. Moreover, the proposed numerical model was competent in reproducing the experimental results of damage initiation and evolution in case of high peak pressure as well as the initial misalignment of the workpiece. The results of this investigation revealed that a rapid compression machine can be utilized efficiently for the controlled forming of complex shapes of metal sheets.

Study on Parameters for Affecting SCI of Sheet Metal Forming

2010 ◽  
Vol 44-47 ◽  
pp. 2862-2866
Author(s):  
Ji Tao Du
Keyword(s):  
Mechanical Property ◽  
Surface Quality ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Friction Condition ◽  
Experimental Results ◽  
Forming Defect ◽  
Punch Radius

The surface contact impression(SCI) is the neglected forming defect and seriously affects surface quality and mechanical property of stamping parts. The technology parameters and affective degree which alleviate or eliminate SCI are researched , four factors including die radius(DR) , die clearance(DC), punch radius(PR) and friction condition(FC) , which each factor chooses three levels are designed and constitute a L9（34）orthogonal table. The experimental results indicate that the significances order of technology parameters affecting SCI is DR> PR > DC >FC. The analyzed result shows that the superior parameter affecting SCI is DR ,the inferior is FC, adapted DC greatly removes SCI. the research puts forward a reference for improving surface quality of stamping parts.

Formability and Surface Finish Studies in Single Point Incremental Forming

2011 ◽  
Author(s):  
A. Bhattacharya ◽  
Samarjit Singh ◽  
K. Maneesh ◽  
N. Venkata Reddy ◽  
Jian Cao
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Surface Finish ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Experimental Results ◽  
Wall Angle ◽  
Incremental Sheet Metal Forming ◽  
Tool Diameter

Incremental sheet metal forming (ISMF) has demonstrated its great potential to form complex three-dimensional parts without using a component specific tooling. The die-less nature in incremental forming provides a competitive alternative for economically and effectively fabricating low-volume functional sheet parts. However, ISMF has limitations with respect to maximum formable wall angle, geometrical accuracy and surface finish of the component. In the present work, an experimental study is carried out to study the effect of incremental sheet metal forming process variables on maximum formable angle and surface finish. Box-Behnken method is used to design the experiments for formability study and full factorial method is used for surface finish study. Analysis of experimental results indicates that formability in incremental forming decreases with increase in tool diameter. Formable angle first increases and then decreases with incremental depth and it is also observed that the variation in the formable angle is not significant in the range of incremental depths considered to produce good surface finishes during the present study. A simple analysis model is used to estimate the stress values during incremental sheet metal forming assuming that the deformation occurs predominantly under plane strain condition. A stress based criterion is used along with the above mentioned analysis to predict the formability in ISMF and its predictions are in very good agreement with the experimental results. Surface roughness decreases with increase in tool diameter for all incremental depths. Surface roughness increases first with increase in incremental depth up to certain angle and then decreases. Surface roughness value decreases with increase in wall angle.

A New Method for Testing Formability in Sheet Metal Forming at Biaxial Tensile State

2014 ◽  
Vol 626 ◽  
pp. 275-280 ◽  
Author(s):  
Rong Shean Lee ◽  
Ta Wei Chien
Keyword(s):  
Experimental Data ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Experimental Results ◽  
New Method ◽  
Dome Height ◽  
Uniaxial Tensile ◽  
Biaxial Tensile ◽  
Theoretical Predictions

This paper presents a new method concerning testing formability in sheet metal forming, especially focuses on clarifying the divergence of the experiment and a variety of theoretical predictions on biaxial tensile state. Up to now, there are many different fracture criteria appeared. All researches have presented their experimental data which could justify the criterion they presented. However, the experimental results and predictions in the first quadrant of the forming limit diagram (FLD) often diverge. Today, limiting dome height test is commonly used for FLD experiment, but specimens are rubbed and bended during the test, both influencing the experimental results.In order to provide for convincible experimental data, this paper presents a new experimental method to establish the first quadrant of FLD. In this method, cruciform biaxial tensile specimen and biaxial tensile apparatus have been developed. The proposed specimen has the feature of thickness reduction and contour design to ensure the fracture location is in the central region, so that accurate biaxial tensile state can be obtained. Through this method, there is an opportunity to obtain the whole FLD using uniaxial tensile testing machine, which is a low-cost alternative in compared with limiting dome height test. Besides, the experimental results can be utilized to clarify the divergence between various theoretical predictions and experimental results in the first quadrant of the FLD.

Formability and Surface Finish Studies in Single Point Incremental Forming

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
A. Bhattacharya ◽  
K. Maneesh ◽  
N. Venkata Reddy ◽  
Jian Cao
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Surface Finish ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Experimental Results ◽  
Wall Angle ◽  
Incremental Sheet Metal Forming ◽  
Tool Diameter

Incremental sheet metal forming (ISMF) has demonstrated its great potential to form complex three-dimensional parts without using a component specific tooling. The die-less nature in incremental forming provides a competitive alternative for economically and effectively fabricating low-volume functional sheet parts. However, ISMF has limitations with respect to maximum formable wall angle, geometrical accuracy, and surface finish of the component. In the present work, an experimental study is carried out to study the effect of incremental sheet metal forming process variables on maximum formable angle and surface finish. Box–Behnken method is used to design the experiments for formability study and full factorial method is used for surface finish study. Analysis of experimental results indicates that formability in incremental forming decreases with increase in tool diameter. Formable angle first increases and then decreases with incremental depth and it is also observed that the variation in the formable angle is not significant in the range of incremental depths considered to produce good surface finishes during the present study. A simple analysis model is used to estimate the stress values during incremental sheet metal forming assuming that the deformation occurs predominantly under plane strain condition. A stress-based criterion is used along with the above mentioned analysis to predict the formability in ISMF and its predictions are in very good agreement with the experimental results. Surface roughness decreases with increase in tool diameter for all incremental depths. Surface roughness increases first with increase in incremental depth up to certain angle and then decreases. Surface roughness value decreases with increase in wall angle.

An Analysis of Drawbeads in Sheet Metal Forming: Part II—Experimental Verification

1987 ◽  
Vol 109 (2) ◽  
pp. 164-170 ◽  
Author(s):  
B. Maker ◽  
S. K. Samanta ◽  
G. Grab ◽  
N. Triantafyllidis
Keyword(s):  
Numerical Model ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Deformation Process ◽  
Coulomb Friction ◽  
Experimental Results ◽  
Automotive Applications ◽  
Coulomb Friction Law ◽  
Two Phases

This paper presents experimental results obtained for a variety of drawbeads typical of automotive applications, and compares the results with those obtained from the numerical model presented in the first part of this work (Triantafyllidis et al., 1986). The deformation process is divided into two phases: the “locking/clamping” phase as the binder closes to form the sheet around the drawbead, and the “pulling” phase as the panel is formed, causing the material to be drawn through the bead. Metals considered are SKDQ steel, aluminum, and brass. Dry and lubricated conditions are investigated. Good correlations between model and experiment are obtained for strain distributions over the sheet and excellent agreement is observed in the binder clamping forces. Using a Coulomb friction law in the model, horizontal restraining forces are compared to experimental results. The model is shown to accurately predict the influence of variations in material, geometry, and friction conditions. However, the correlation between the model and experiment is not as good in two cases: as the punch (male bead) reaches the “locked” condition, and in the initial stages of “pulling” deformation. Reasons for the discrepancies are discussed.

scholarly journals Numerical and experimental investigation of the effect of process parameters on sheet deformation during the electromagnetic forming of AA6061-T6 alloy

2020 ◽  
Vol 11 (2) ◽  
pp. 329-347
Author(s):  
Zarak Khan ◽  
Mushtaq Khan ◽  
Syed Husain Imran Jaffery ◽  
Muhammad Younas ◽  
Kamran S. Afaq ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Process Parameters ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Sheet Thickness ◽  
Electromagnetic Forming ◽  
Experimental Results ◽  
Thickness Variation ◽  
Fe Model ◽  
Sheet Deformation

Abstract. Electromagnetic forming is a high-speed sheet metal forming technique to form metallic sheets by applying magnetic forces. In comparison to the conventional sheet metal forming process, electromagnetic forming is a process with an extremely high velocity and strain rate, which can be effectively used for the forming of certain difficult-to-form metals. During electromagnetic forming, it is important to recognise the effects of process parameters on the deformation and sheet thickness variation of the sheet metal. This research focuses on the development of a numerical model for aluminium alloy (AA6061-T6) to analyse the effects of three process parameters, namely voltage, sheet thickness and number turns of the coils, on the deformation and thickness variation of the sheet. A two-dimensional fully coupled finite-element (FE) model consisting of an electrical circuit, magnetic field and solid mechanics was developed and used to determine the effect of changing magnetic flux and system inductance on sheet deformation. Experiment validation of the results was performed on a 28 KJ electromagnetic forming system. The Taguchi orthogonal array approach was used for the design of experiments using the three input parameters (voltage, sheet thickness and number of turns of the coil). The maximum error between numerical and experimental values for sheet thickness variation was observed to be 4.9 %. Analysis of variance (ANOVA) was performed on the experimental results. Applied voltage and sheet thickness were the significant parameters, while the number of turns of the coil had an insignificant effect on sheet deformation. The contribution ratio of voltage and sheet thickness was 46.21 % and 45.12 % respectively. The sheet deformation from simulations was found to be in good agreement with the experimental results.

ИССЛЕДОВАНИЕ ТОЧНОСТИ ДЕТАЛЕЙ, ПОЛУЧАЕМЫХ ПРИ РАЗДЕЛИТЕЛЬНЫХ ОПЕРАЦИЯХ В ПЕРЕНАЛАЖИВАЕМЫХ ШТАМПАХ

2018 ◽  
pp. 52-63
Author(s):  
Е. А. Фролов ◽  
В. В. Агарков ◽  
С. И. Кравченко ◽  
С. Г. Ясько
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Balance Method ◽  
Experiment Planning ◽  
Practical Recommendations

To determine the accuracy of the readjustable punches for separating operations (perforation + punching out) of sheet-metal forming, the accuracy parameters were analyzed using the random balance method using the method of experiment planning. Analytical dependencies are obtained to determine the values of deviation of the outer and inner contour dimensions of perforated and punched out sheet parts. From the dependencies obtained, it is possible to estimate and predict the value of deviation in the dimensions of the resulting part at any time during the operation of the punch. Practical recommendations on the calculation of the actuating dimensions of the working elements (stamping punch, matrix) of readjustable punches are offered.

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