• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.03a
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• pp.118-128
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• 1994

The planar anisotropic FEM analysis for predicting the earing profiles and draw-in amounts in the deep-drawing processes is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-based unit vectors and the normal contact pressure. the consistent full set of governing relations, comprising equilibrium and geometric constraint equations, is appropriately linearized. Barlat's strain-rate potential is employed, whose in-plane anisotropic properties are taken into account with anisotropic coefficients and potential parameter. The linear triangular membrane elements are used for depicting the formed sheet. with the numerical simulations of deep drawing processes of flat-top cylindrical cup for the 2090-T3 aluminum effects on the earing behavior are examined. Earing predictions made for the 2090-T3 aluminum alloy sheet show good agreement with experiments, although some discrepancies were observed in the directional trend of cup height and thickness strains.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.173-178
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• 2001

The materials processing factors such as remelting and casting, heat treatment and microstructure, sheet rolling and can body forming in the aluminum can-to-can recycling procedure have been investigated. Aluminum used beverage can(UBC) was remelted together with virgin aluminum. The ceramic filter was used during casting to remove large impurities. As-cast microstructure was composed of large intermetallic compound (mainly $\beta$ -phase) distributed in the aluminum matrix. By heat treatment, $\beta$ -phase was transformed to $\alpha$ -phase which was also formed from $Mg_2$Si particles. The heat treated ingots were hot-rolled at 48$0^{\circ}C$ and cold-rolled to thin sheets. Can making from this thin sheets was successful and earing was measured after can making. There was a critical cold reduction rate for minimum earing. Some cracks were initiated from the impurity particles which was not removed during filtering.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.288-292
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• 2003

The main purpose of this paper is the development of the system which measures the earing rate of aluminum CAN with the CCD camera. In order to optimize imput image, the image object was segregated and the position of the image grasped. In the pre-processing the edges were detected by the Robert mask after improving the definition of image by the histogram equalization. The height of four each ear and angles which occur due to the characteristics of the aluminum CAN are measured manually with the digital vernier calipers in the industrial ground and in the case of the velocity, these require 30 seconds at least by three times measurement per height of one direction of the aluminum. But it took 0.02 seconds when this system was applied. Therefore this system is proven the satisfactory efficiency and reliability as compared to the control result of in industrial ground.

• Transactions of Materials Processing
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• v.4 no.3
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• pp.222-232
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• 1995

The planar anisotripic FEM analysis for predicting earing profiles and draw-in amounts in the deep-drawing process is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-based unit vector and normal contact pressure. The consistent full set of governing relations, which is comprising euilbrium and geometric constraint equations, is appropriately linearized. Barlat's strain-rate potential is employed, whose in-plane anisotropic properties are taken into account with anisotropic coefficients and potential parameters. The linear triangular membrane elements are used for depicting the formed sheet. In the numerical simulations of deep drawing processes of a flat-top cylindrical cup for 2090-T3 aluminum alloy sheet show good agreement with experiments, although some discrepancies were observed in the directional trend of cup height and thickness strains.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.1
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• pp.8-14
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• 2005

The implementation of vision system using CCD camera which measures the earing rate of aluminium CAN is represented in this paper. In order to optimize the input image, the object of the input image is separated and the position of the image is calibrated. In the preprocessing, the definition of image is improved by the histogram equalization, and then the edges of the input image are detected by the Robert mask. The heights of the four ears and angles of the aluminium CAN are measured manually with the digital vernier calipers in industry. It takes 30 seconds to measure manually the height of one direction of the aluminium CAN at least three times. However, when the proposed system in this paper is applied, it takes 0.02 seconds only. In conclusion, the efficiency of the proposed system is higher than that of the system used in the industry.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.59-65
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• 2014

As for Ethephon treatment, the heading stage is 2 days later at the concentration of 250 ppm and 500 ppm for the booting stage that when there is no treatment, 4 days later at the concentration of 1000 or more ppm but no difference for the blossoming and ripening stage. The culm length get shorter as the concentration of Ethephon is higher and the rate of culm length damaged is 37% for 1500 ppm of booting stage, which is the most effective processing, and the inferior culm length damage rate is bigger than the superior culm length damage rate. There is no difference between the number of glumous flower, culm and litter weight and the non-processing and as for the thousand grain weight, it is slightly bigger than when there is not any processing. The rate of germination is indifferent, the number of seeds get numerous regardless of the concentration of treatment and the number augments by 5% maximum for the booting stage. The number of days it takes from treatment of desiccant to the moisture content for harvesting time is respectively 15 days for seeds of 30 day-treatment, 10 days for seeds of 35 days-treatment and 5 days for seeds of 40 to 45 day-treatment. As for the harvest time after treatment of desiccant, the treatment at $30^{th}$ days and $35^{th}$ after the earing is 8 days earlier than the culture by conventional methods, 8 days earlier for the treatment at $40^{th}$ day. When the desiccant treatment is implemented, the thousand grain weight is heavier as the number of days of treatment gets later. The rate of germination gets higher as the number of days of treatment after earing gets later but there is no statistically significant difference 35 days after the earing. Yields are 37% compared to the culture by conventional methods for the treatment of 30 days after the earing, 70% compared to the culture by conventional methods for the treatment of 35 days after the earing, and 92% compared to the culture by conventional methods for the treatment of 40 days after the earing. The treatment before the physiological maturity impacts greatly upon the quality of seeds.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.58-61
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• 1998

Anisotropy is closely related to the formability of sheet metal and should be considered carefully for more realistic analysis of actual sheet metal forming operations. In order to better describe anisotropic plastic properties of aluminum alloy sheets, a planar anisotropic yield function which accounts for the anisotropy of uniaxial yield stresses and strain rate ratios simultaneously was proposed recently[1]. This yield function was used in the finite element simulations of cup drawing tests for an aluminum alloy 2008-T4. Isotropic hardening with a fixed initial back stress based on experimental tensile and compressive test results was assumed in the simulation. The computation results were in very good agreement with the experimental results. It was shown that the initial back stress as well as the yield surface shape have a large influence on the prediction of the cup height profile.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.48-53
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• 2017

Many construction accidents can be lead to a death occurring at construction sites. These are considerably due to potentially-hazardous equipment and machine or unexpected collapsion at earth work due to land slide and so on. Almost 50% of the total death and injury, occurred in construction sites in 2015. 66% of those serious accidents are due to falling occurring from construction sites when they work. Therefore, causes and recommendations of each accident should be deeply thought and analysed The indirect causes are directly related to safe consciousness of the construction workers. Actually, their safety consciousness are not high, even very low, it is thought. Questionnaire survey sheets have been distributed to Seoul, Incheon, and Gyunggi-Do area, first. And then, the authors have collected those directly at sites, in order to increase collection rate of the sheets. The totally, collected sheets are 295 sheets. And, they are analysed using SPSS version 19 package program. Workers internal consciousness has been investigated and reviewed and analysed by statistical method such as frequency rate, crossed, and correlated analysis. And finally the conclusions for the above analyses are as follows; Heavy weight worth a crew of more than two workers should be necessarily considered for the advanced safety plan and needed for making a highly potential hazard group at construction sites. Safety consciousness, earing p.p.e, workman ship should be mainly considered for investing safety costs with an aspect of human factor.