Numerical and Experimental Explorations for the Formability of Drawing Square Cups Through Deep Drawing Operation (January 2020)

2020 ◽  
Vol 38 (9A) ◽  
pp. 1316-1326
Author(s):  
Nareen H. Obaeed

This study aims to examine the formability of drawing cups having square shapes through direct deep drawing process on a single action press through one pass. This can be accomplished by conducting an FE simulation and performing an experimental investigation on steel substrate type AISI 1008 blank with diameter and thickness dimensions 80, 0.5 mm respectively. To explore and analyze the formability of such a drawing process, two process parameters have been included in this work which is the speed of punch (30 and 300 mm/min) and the lubrication state (with machine oil and dry drawing). Both direct and indirect measurements of thickness strain have been adopted as an indicator of the sheet formability. The results of both FE simulation and experimental work demonstrate that the square drawing of the AISI sheet has been accomplished for all the four cups produced since the highest thinning over the cup wall does not exceed 25% of the original thickness. Generally, there is a good match between the experimental values of the indirect method and the FEM results for all models such that the largest deviation is about 25%. The direct method of thickness measurement is determined to be non-confident as strain values are practically unacceptable. Additionally, higher formability of the sheet has been realized at lower punch speeds. Furthermore, no significant difference has been observed in the formability at both speeds of punch when using a lubricant compared to the dry drawing operation.

2020 ◽  
Vol 4 (4) ◽  
pp. 122
Author(s):  
Peter Birnbaum ◽  
Enrique Meza-García ◽  
Pierre Landgraf ◽  
Thomas Grund ◽  
Thomas Lampke ◽  
...  

Hot formed sheet components made of Martensitic Stainless Steels (MSS) can achieve ultra-high strengths in combination with very high corrosion resistance. This enables to manufacture complex lightweight sheet components with longer lifespan. Nevertheless, the hot formability of MSS sheets has not been accurately evaluated considering high temperatures and complex stress and strain states. In this work, the hot sheet formability of three MSS alloys under thermomechanical process conditions was investigated. Initially, mechanical properties of this sheet material were determined by uniaxial tensile test. Finite Element Method (FEM) simulation of a hot deep drawing process was performed under consideration of thermo physical calculated material models using the software JMatPro® and Simufact Forming® 15.0. The resulting strains and cooling rates developed locally in the work piece during the forming process were estimated. The numerical results were validated experimentally. Round cups were manufactured by hot deep drawing process. The resulting maximum drawing depth and hardness were measured. In general, all three alloys developed very good formability at forming temperatures between 700 and 900 °C and increased hardness values. However, they are highly susceptible to chemical composition, austenitization temperature, dwell time, and flange gap. A statistic approach is given to explain the correlation between hardness and its influencing factors.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3993
Author(s):  
Thanh Trung Do ◽  
Pham Son Minh ◽  
Nhan Le

The formability of the drawn part in the deep drawing process depends not only on the material properties, but also on the equipment used, metal flow control and tool parameters. The most common defects can be the thickening, stretching and splitting. However, the optimization of tools including the die and punch parameters leads to a reduction of the defects and improves the quality of the products. In this paper, the formability of the camera cover by aluminum alloy A1050 in the deep drawing process was examined relating to the tool geometry parameters based on numerical and experimental analyses. The results showed that the thickness was the smallest and the stress was the highest at one of the bottom corners where the biaxial stretching was the predominant mode of deformation. The problems of the thickening at the flange area, the stretching at the side wall and the splitting at the bottom corners could be prevented when the tool parameters were optimized that related to the thickness and stress. It was clear that the optimal thickness distribution of the camera cover was obtained by the design of tools with the best values—with the die edge radius 10 times, the pocket radius on the bottom of the die 5 times, and the punch nose radius 2.5 times the sheet thickness. Additionally, the quality of the camera cover was improved with a maximum thinning of 25% experimentally, and it was within the suggested maximum allowable thickness reduction of 45% for various industrial applications after optimizing the tool geometry parameters in the deep drawing process.


Author(s):  
Hamidreza Gharehchahi ◽  
Mohammad Javad Kazemzadeh-Parsi ◽  
Ahmad Afsari ◽  
Mehrdad Mohammadi

1993 ◽  
Vol 115 (2) ◽  
pp. 224-229 ◽  
Author(s):  
K. Yamaguchi ◽  
K. Kanayama ◽  
M. H. Parsa ◽  
N. Takakura

A new deep drawing process of sheet metals is developed to facilitate small-lot production of deep cups with large drawing ratio. In this process, unlike the conventional deep drawing method, a few drawn cups are always stacked on the punch and used as a part of punch for the subsequent deep drawing of a given blank. Before drawing a new blank, a drawn cup which is in contact with the punch is stripped off. The repetition of such stripping and drawing operations makes it possible to carry out both the first-stage drawing and the subsequent slight redrawings in one drawing operation using only one pair of punch and die. In this paper, this new deep drawing process is applied to the production of tapered cups and the main feature of the process is shown.


2014 ◽  
Vol 53 ◽  
pp. 797-808 ◽  
Author(s):  
H. Zein ◽  
M. El Sherbiny ◽  
M. Abd-Rabou ◽  
M. El shazly

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