• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.322-325
• /
• 2007

Dent resistance is an important characteristic to avoid damage on automotive outer panels. From a practical point of view, dents can be caused in a number of ways. Considering doors as an example, denting can occur from stone impacts or from the careless opening of an adjacently parked vehicle door. Denting can occur where the door surface is smooth and may not have sufficient curvature to resist dent. These exterior body parts are designed to improve dent resistance using a combination of work hardening and bake hardening. In brief, dent is affected by the shape of the parts and the material properties such as yield strength, strain and thickness. In this work, forming of door outer panel is investigated by Taguchi method. Main parameters are yield strength, thickness, blank size, blank holding force and so on. For the given value of design parameters, forming analysis of the thirty six cases are carried out according to L18 orthogonal array. After comparing the performance by simple conversion of simulation results into dent resistance, the final suggestion of the forming parameters is verified for the best improvement of dent resistance.

• Transactions of Materials Processing
• /
• v.24 no.4
• /
• pp.280-286
• /
• 2015

Hemming is used to connect two sheet metal components by folding the edge of an outer panel around an inner panel to create a smooth edge. The minimization of hemming defects is critical to the final quality of automobile products because hemming is one of the last operations during fabrication. Designing the hemmed part is not easy and is influenced by the geometry of the bent part. Therefore, the main problem for automotive parts is dimensional accuracy since formed products often deviate geometrically due to large springback. Few numerical approaches using 3-dimensional finite element model have been applied to hemming due to the small element size which is needed to properly capture the bending behavior of the sheet around small die corner and the comparatively big size of automotive opening parts, such as doors, hoods and deck lids. The current study concentrates on the 3-dimensional numerical simulation of hemming for an automotive door. The relationship between the design parameters of the hemming operation and the height difference defect is shown. Quality improvement of the automotive door can be increased through the study of model parameters.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.9
• /
• pp.887-895
• /
• 2017

This paper presents a study on the accelerated life tests of parts that operate during the opening and closing of door frames, particularly door hinges. Hinge theoretical verification and validation of the test equipment in the present study and the different structures and fault mode, depending on the purpose of usage analysis, failure mode for one of the hinges of the switchgear components used for electromagnetic shielding facilities and on-site operating conditions. The accelerated life test was designed for the characteristic lifetime prediction of the components, by estimating the shape parameter and the acceleration factor.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.583-588
• /
• 2004

Opening commercial service of KTX at the time of demanding more flexible train set for HONAM line and JEONLA line, it's necessary for the Korean High speed train, performing the stabilization; to modify the design in aspect of passenger and maintenance. In order to ensure the optimized interior design in Korean High speed train, it is necessary to review the major items such as disabled passenger facility, toilet, seat arrangement, compartment partition and door, access door, electrical cabinet, color and paint through the European standard and compare with other high speed train.

• Transactions of Materials Processing
• /
• v.13 no.2
• /
• pp.115-121
• /
• 2004

Hemming is the last farming process in stamping and determines external quality of automotive outer panels. Few numerical approaches using 3-dimensional finite element model have been applied to a hemming process due to small element size which is needed to express the bending behavior of the sheet around small die comer and comparatively big model size of automotive opening parts, such as side door, back door and trunk lid etc In this study, part model assembling method is suggested and applied to the 3-dimensional finite element simulation of flanging and hemming process far an automotive front hood.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2002.05a
• /
• pp.103-107
• /
• 2002

The 2nd forming process of flanging/hemming has recently many interest because it determines external quality of automobile. It is difficult to apply finite element simulation in flanging/hemming due to small element size which needs for expression of bending effect on the die corner and big model size of side door, back door, tank lid and like opening Parts. This paper shows the process of flanging/hemming simulation using finite element model for automotive panels. The explicit finite element program PAM-STAMP$\^$TM/ was used to simulate the flanging and hemming operations.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.97-98
• /
• 2022

The purpose of this study is to find out the failure conditions of fire doors in the process of use and prepare maintenance measures against them and find out the failure conditions and failure rates of fire doors according to the period of use of buildings. According to a survey of the failure rate and failure factor of fire doors, the failure rate of fire doors under 5 years was 3.7%, 13.4% of fire doors under 5 years and 10 years, and 14.8% of fire doors under 15 years and 27.6% of fire doors over 20 years. In particular, 15 years later, the failure rate of fire doors exceeded 20%. The main defects were found to be natural aging, holes, opening and closing failures, gaps, and failure and wear of accessories such as gaskets and door closers.

• Transactions of Materials Processing
• /
• v.9 no.6
• /
• pp.624-630
• /
• 2000

Typical automotive opening parts, i. e. hood trunk lid and door, are made through the press operations such as drawing, trimming, flanging, and hemming. The dimensional accuracy of stamped panels is mainly dependent on the drawing operation. However, the gap between outer panels and opening parts, which is important to the appearance quality of the assembled body, is directly influenced by the flanging and hemming operation. In this study, the relation between the design parameters of the hemming operation and the defect of roll-in is shown. The effects of some design parameters on the gap are examined using CAE. furthermore, the simulated results of the hemmed part of tailgate comer are shown and discussed.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2009.04a
• /
• pp.372-378
• /
• 2009

고충건물 피난경로의 제연시스템은 일반적으로 급기가압방식이 널리 쓰인다. 그러나 국내에서 널리 쓰이는 부속실 단독 가압방식은 공간용적이 너무 작아 차압을 형성하고 유지하는 문제와 방연풍속을 형성하는 문제 사이에 늘 불균형이 존재한다. 또한 거실 출입문을 여닫는 데 지장이 없는 차압 하에서도 계단실 출입문은 차압에 밀려 제대로 닫히지 않는 경우가 있을 수 있다. 이런 측면을 역학적으로 검토하고, 과압 해소방식을 제안한다.

• Fire Science and Engineering
• /
• v.27 no.2
• /
• pp.6-10
• /
• 2013

This study aims to construct the performance data for smoke-control zone and realize the safety of injection and pressurization room which is composed of supply air pressure zone, vestibule, smoke-control zone and stairwell. To obtain this, smoke-control system and the device of the opening-closing force of fire door are manufactured. This subject is the analysis of the closing force, angular velocity and fire door size in the case of fixed volume flow rate. Based on the results, closing force increased as fire door size and closing angular velocity increases. Also, it is remark that there exists a critical angular velocity, which maintains constant maximum closing force even though the angular velocity increases more.