• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.44-47
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• 2000

In industrial practice caliber design in shape rolling depends on the designer's experience which in general is obtained through costly trial-and error process. Demonstrated in this paper is an application of the finite element method to the determination of optimal caliber shapes in shape rolling of LM-Guide.

• Journal of the Korean Society of Systems Engineering
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• v.4 no.1
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• pp.31-34
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• 2008

As a supply contract for 100 new high-speed rolling stocks(KTX-II) was made 8th June 2006, System Engineering process has been applied to introduce the high-speed rolling stocks successfully and to manage the total life cycle systematically from Pre-concept Phase, Contract Phase, Preliminary and Critical Design Review, Production, Test and Verification, Acceptance and Operation to assurance for a flaw.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.489-496
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• 1998

Although the surface of aluminum alloy has good corrosion resistance property, the surface of the aluminum rolling stock should be painted for good appearance and protection of the body. For better painting of the aluminum carbody, the surface must also be well pretreated. In this paper, painting process of the aluminum rolling stock is described and the test results of the painted surface is presented. As accumulated data concerning to the painting technology for the aluminum rolling stocks are absent in our country, the presented test results will be helpful for mass production of aluminum rolling stocks in the near future.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.129-133
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• 2001

A finite element-based, integrated process model is presented for a three dimensional, coupled analysis of the thermo-mechanical behavior of the strip and work roll in the continuous hot strip rolling. The validity of the proposed model is examined through comparison with measurements. The effect of Edge-Heater on the finishing delivery temperatures is examined by using the present model. The models capability of revealing the effect of diverse process parameters is demonstrated through a series of process simulation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.183-186
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• 2003

A finite element-based, integrated process model is presented for a three dimensional, coupled analysis of the thermal and mechanical behavior of type 304 stainless slab during hot charge rolling (HCR) and cold charge rolling (CCR) processes. The validity of the proposed model is examined through comparison with measurements. The susceptibility on micro-crack initiation or propagation due to the thermal stress in these two different process conditions was examined. The model's capability of revealing the effect of diverse process parameters is demonstrated through a series of process simulation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.52-55
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• 2000

Investigated via a series of finite element process simulation is the effect of diverse process variables on some selected non-dimensional parameters characterizing the strip in hot strip rolling. Then on the basis of these parameters an on-line model is derived for the precise prediction of roll and roll power. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.297-306
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• 2004

This study investigated Austenite Grain Size (AGS) distribution in Low-Speed Round-Oval Rolling. Rolling experiments were done along with the AGS numerical modeling to characterize the final AGS distribution and its kinetics behavior. For bar rolling experiment, we utilized the pilot rolling mill, operating at 34 fixed rpm, at POSCO Technical Research Laboratories. To investigate the microstructural observation, the rigid-viscoplastic finite element analysis was combined with Hodgson's AGS evolution model. To consider the transient thermal history in the integrative AGS modeling, additivity rule was introduced. The integrated analysis revealed that static or meta-dynamic recrystallization is responsible for the AGS difference in the inner or outer region of rolled bar. Comparative study showed that the current AGS modeling approach can be used to model the overall AGS distribution in bar rolling processes. For more accurate AGS prediction, the AGS modeling method should be verified under the various rolling conditions such as different rolling speeds and different deformations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1255-1260
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• 2012

The densification behavior of titanium powder in the direct powder rolling process was investigated. An analytical model for the roll-backlash phenomenon during this process was proposed to conduct a realistic finite element analysis. Furthermore, the roll-backlash was quantitatively analyzed, and the relative densities of the greenstrip along the rolling direction were precisely estimated. Finally, the slip and nip phenomena were identified by calculating the contact pressure and shear stress between the titanium powder and the roller in order to understand the densification behavior of the powder during the rolling process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.128-131
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• 2009

In this paper, three-dimensional finite element analysis of screw rolling process of a long shaft bolt is conducted by using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of forging and screw rolling processes is simulated to reveal the mechanism of screw formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.27-37
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• 2011

Currently, in the course of introducing rolling stocks, RAMS standard and management by system engineering method apply to rolling stock system. Technical elements and results applied in system introduction phase are just used in acquisition stage, and these are not applied to the standard in railway site. Therefore, it is difficult to apply to standardized technology and quality assurance measure. Due to the establishment of the EU, railway operation system is internationalized and the international railway standards are being discussed in various ways. In addition, standardization is expanded from manufacture to operation and maintenance. It is to provide consistent standard in quality, cost calculation of maintenance technology, maintenance technology and quality assurance in case of international railway safety incidents. Therefore, this study is to find technology, quality and cost management model to be used for choosing railway-operation guidance by considering how technologies & quality have changed in system life cycle, compared with estimated standards, based on the technologies & quality-related result in the process of getting new rolling stocks and management guidance for operation & maintenance process.