• 한국자동차공학회논문집
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• 제11권3호
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• pp.131-137
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• 2003

Proper door effort, required force to open or close a vehicle door, is an essential door design factor for the safety of passengers and pedestrians. Section shape of the door checker arm is the most influential design parameter for achieving a door effort design target. In this research. an analysis procedure to predict door effort using a simplified plane strain finite element model wes investigated for two passenger cars, for which mechanism of checker systems were: different. The variation of checker arm force to be required during moving on arm in opening and closing direction was estimated through analysis, and the result was transformed to the door effort with respect to door opening angle by considering door characteristics. Also, the self·closing force due to door weight was theoretically calculated and added to the door effort from checker arm force. Finally the estimated results of door effort were compared with test results.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.52-57
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• 2012

Proper door effort is required for the safety of passenger and pedestrian while securing door operating convenience. 3D finite element analyses for a hybrid door checker were carried out to estimate door checker arm resistance force. And, from the estimated door checker arm resistance force and theoretically calculated self-closing force, door effort was predicted. The analysis results at checker arm peaks showed excellent correlation with the test results. Also, in order to reduce solving time, a modified model with simple spring element was investigated. Finally an equation to easily calculate checker arm resistance force from checker arm shape and spring constant was suggested and its usefulness in early design stage was discussed.

• 한국기계가공학회지
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• 제11권3호
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• pp.86-91
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• 2012

Door effort was calculated for a new door checker with torsion bar spring and integrated checker case by FE analysis. A hybrid checker arm which has peaks and valleys only on the upper surface was adopted to reduce noise in operation and make operation with more distinctive steps. The checker arm was modeled using shell elements to estimate both the longitudinal and the lateral resistance force by checker arm. By combining the checker arm resistance force obtained from analysis and the door self-closing force by the theoretical calculation, door effort was predicted to show the good correlation with test results. In addition the unrolling effect of roller model was investigated and a new roller type for more smooth rolling was studied.

• 제어로봇시스템학회논문지
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• 제16권6호
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• pp.532-538
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• 2010

SD (Smart Door) is a human friendly power-assisted door system initially targeted for passenger car doors. The Smart Door offers comfort and safety to passengers or/and drivers by supplying additional power. Amount of power supplied by the Smart Door system is depend on the environment where the automotive is situated. It realizes comfort, for example, when the force applied by the passenger to the door is expected to be abnormal, the SD system tries to compensate passenger's effort by supplying additional force. In this study, to enhance the ease of opening and closing the doors of the passenger vehicle, a Smart Door with a power assist mechanism consisting of a motor was developed and analysed. A power assist mechanism mounted within the vehicle's door is designed and modeled for simulation purpose. The required force necessary to control the designed mechanism during the vehicle's roll, pitch and the opening angle of the door has been considered. To this end, we propose a power-assisting control strategy called "gravity cancellation". The system is analysed by numerical simulation with the gravity cancellation control algorithm.

• 소성∙가공
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• 제26권1호
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• pp.55-62
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• 2017

This paper proposes the process to develop a light-weighting automotive door assembly using high strength steel with low cost penalty. In recent years, the automotive industry is making an effort to reduce the vehicle weight. In this study, inner panels for automotive front door using thinner sheets and quenchable boron steel were designed to reduce the weight of conventional one. In order to evaluate the stiffness properties for the proposed door design, the several static tests were conducted using the finite element method. Based on the simulation results, geometry modifications of the inner panels were taken into account in terms of thickness changes and cost saving. Furthermore, a prototype based on the proposed design has been made, and then static stiffness test carried out. From the results, the proposed door is proved compatible and weight reduction of 11.8% was achieved. It could be a reference process for automotive industry to develop the similar products.

• 디자인학연구
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• 제17권1호
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• pp.179-190
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• 2004

개인생활의 프라이버시와 외부로부터 자신의 안전성(Safety)을 확보하고자하는 노력은 오늘날 기술의 진보와 더불어 보안시스템의 발전을 가져왔다. 특히 아파트형태의 주거생활이 보편화되면서 프라이버시의 확보와 외부침입으로부터 자신과 가족의 보호라는 측면에서 도어락시스템(Door Lock System)의 역할과 기능의 중요성이 증대되고 있다. 이러한 추세에 발맞추어 기술의 발전뿐만 아니라 사용자중심의 다양한 방법의 인터페이스에 대한 연구가 이뤄지고 있으며 그 일환으로 지문이나 홍체인식과 같은 최첨단의 보안시스템이 등장하고 있다. 본 연구는 암호화기술(Advanced Encryption Standard)을 적용하여 보안과 안전성을 확보함과 동시에 사용자가 쉽게 작동하고 사용할 수 있는 인터페이스를 바탕으로 한 도어락 개발에 초점을 두고 있다. 특히 가격 면에서도 기존제품과 경쟁력을 가질 수 있고, 보다 근본적으로 도어락 뿐만 아니라 전반적인 잠금장치에 대한 새로운 가능성과 방법을 모색해 봄으로써 향후 잠금장치와 보안시스템에 대한 대안을 제시코자 한다.

• 소성∙가공
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• 제19권3호
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• pp.185-190
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• 2010

Application of CAE analyses are wide spread in shaping processes and structural safety verification of plastic products. The importance of CAE analysis and its contributions are getting increase since the processibility and structural safety of product can be predicted. CAE analysis for complex shaped product need a lot of time for modeling and computation compare with simpler one. Therefore careful simulation modeling is required for complex shaped product. Structural analysis for plastic door handle of automobile has been performed and structural safety has been investigated for various load directions and modeling cases. Large stress occurred at the hinge in handle regardless of load direction and modeling case. Consequently hinge is considered structurally very weak among the parts in plastic door handle. It is concluded that simple modeling rather than total modeling with adequate boundary condition equivalent to real situation gives reasonable computational results with saving modeling effort and computation time.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.85-96
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• 1996

Most protection systems such as seat belts and airbags are not effective means for side structure. There has been significant effort in the automobile industries in seeking other protective methods, such as stiffer structure and padding on the door inner panel. Therefore, a car-to-car side impact model has been developed using ATB occupant simulation program and validated for test data of the vehicle. Compared to the existing side impact models, the developed model has a more detailed vehicle side structure representation for the more realistic impact response of the door. This model include impact bar which effectively increases the side structure stiffness without reduction of space between the occupant and the door and padding for absorbing impact energy. The established model is applied to a 4-door vehicle. The parameter study indicated that a stiffer impact bar would reduce both the acceleration-based criteria, such as thoracic trauma index: TTI(d), and deformation-based criteria, such as viscous criterion(VC). Padding on the door inner panel would reduce TTI(d) while VC gives the opposite indication in a specified thickness range. For a 4-door vehicle, the stiffness enhancement of B-pillar is more beneficial than that of A-pillar for occupant injury severity indices.

• 한국안전학회지
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• 제31권4호
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• pp.156-163
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• 2016

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

• 한국CDE학회논문집
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• 제14권4호
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• pp.242-253
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• 2009

Nowadays, manufacturing industry has been making its effort not only for productivity elevation but also for cost reduction in order to survive in the global market which is more and more challenging. In this paper, the method for planning of digital manufacturing system is proposed and door trim assembly system is determined as the subject of our research. First of all, the process sequence is generated based on the product analysis. And, the static and dynamic relationships between system components are represented using IDEF0 and UML model. The working time is estimated through the regression analysis based on MODAPTS method. According to the system configuration strategy, initial concept system layout is implemented 3D virtual environment. The problems caused by bad working motions are detected and modified through the ergonomic analysis using RULA method. According to proposed procedure, digital door trim assembly system is implemented in DLEMIA.