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Showing 3 results for Square Cup
S.m.h. Seyedkashi, Farzad Rahmani, Hossein Amirabadi, Mohammad Hoseinpour Gollo,
Volume 16, Issue 11 (1-2017)
Abstract
In hydromechanical deep drawing process, the traditional matrix is replaced by pressurized fluid, and the final shape is determined based on the shape of a rigid punch. It is required to change the fluid pressure within the allowed working zone during the process to prevent the workpiece from rupturing and wrinkling,. Working zone curve represents the range of maximum available drawing ratios without rupture under the highest chamber pressure. In this paper, hydromechanical deep drawing of square cups made of aluminum-steel double layer sheets are studied by experiments and finite element simulations. In order to detect the rupture onset in simulations, experimental forming limit diagrams were obtained using for aluminum/steel double layer sheet. Experimental data were used to validate the finite element model. The effects of process parameters such as thickness of the various layers, prebulge pressure, chamber pressure and the friction coefficient were investigated on the working zone and the process window. The numerical results show that an optimum amount for the drawing ratio exists for each prebulge pressure. Also, with increasing the chamber pressure, shrinkage is reduced on the flange area. With increasing the friction between the sheet and matrix or the sheet and blank-holder, working zone becomes smaller; while with increasing the friction between the sheet and the punch it becomes larger. Experiments were performed for different drawing ratios to evaluate the numerical results, in which a good agreement was observed.
S. Haji Ahmadi, M. Elyasi, M. Shakeri,
Volume 19, Issue 10 (10-2019)
Abstract
In this research, a dimensionless model was developed based on the geometric parameters for the deep drawing process to reduce the manufacturing cost of square cup deep drawing in the large scales. In the following, a series of groups were found for dimensionless ratios based on the geometric parameters of the square cup by Π-Buckingham dimensional analysis method in the two states of circular and square sheets. In order to find the best group of dimensionless geometric parameters, three scales of cups were numerically evaluated by commercial finite elements software. The results were validated by an experimental test. After analyzing all the effective geometric parameters, a fittest dimensionless equation was obtained. The st12 metal sheet was used for experimental validation in the room temperature. Moreover, the results and tearing force as target parameter were compared in simulation states, experimental tests and the proposed dimensionless model based on Π-Buckingham theory. By comparing the results in the two states of the circular and square sheets, it can be concluded that the geometric characteristics of the main scale sample can be predicted by a sample in a small size through the proposed dimensionless model. Comparison of the results of the dimensionless model and experiments show that the proposed model has high accuracy in predicting the tearing force and geometric parameters in the square cup deep drawing process.
M. Khalili, M. Bakhshi Jooybari, H. Gorji,
Volume 20, Issue 10 (10-2020)
Abstract
Research results performed by researchers have illustrated that applying electric current to a deforming metal can lead to a reduction in the required deformation force and an improvement in the formability. This technique is known as electrically assisted forming and is used in various forming processes. In this paper, the forming of square cups through electrically assisted deep drawing process was investigated experimentally and the effects of process parameters, including current magnitude, pulse frequency, and waveform (sinusoidal and square) on the forming force, thickness distribution, and drawing depth are examined. In this regard, after designing and preparing the test setup and forming square cups, the experimental results obtained were compared to those of the conventional deep drawing tests. The results showed that increasing the current magnitude leads to reducing the maximum thinning and the forming force in the deep drawing process of the formed parts. Furthermore, it was found that at a higher frequency, the deformation force decreases significantly and thickness distribution becomes more uniform. The comparison of the two waveforms of pulses demonstrated that the sinusoidal waveform has a relatively more significant effect on the reduction of the force and thickness distribution and a considerable effect on the drawing depth.
