• 한국산학기술학회논문지
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• 제8권5호
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• pp.968-972
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• 2007

자동차 범퍼시스템은 자동차의 외형을 결정할 뿐만 아니라 충격으로부터 차체와 보행자를 보호하는 중요한 역할을 수행한다. 본 연구에서는 범퍼시스템을 해석하기 위하여 컴퓨터 시뮬레이션이나 충격테스트에 의존하지 않고 효과적으로 범퍼시스템을 설계하기 위한 설계기술을 개발하였다. 이를 위해서 차체를 외부 충격으로부터 보호하기 위해 충분한 강도 및 강성을 확보해야 한다는 것과 동시에 충돌 시 보행자 보호를 위해 충분한 연성을 확보해야 하는 조건을 만족시킬 수 있는 빔의 단면과 폼의 두께 또는 물성을 결정해야 한다. 본 연구에서는 설계자가 설계 초기단계에서 위의 제약 조건들을 만족하는 최적의 범퍼구조를 신속하게 결정할 수 있는 신뢰성 있는 설계기술을 개발하였다.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.175-180
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• 2016

폐 자동차에서 떼어낸 범퍼는 분쇄 및 도장 (paint)제거 공정을 거친 후 신재 (pristine materials)와 일정 비율 혼합하여 자동차 부품을 제조하는 공정에서 재활용된다. 본 연구에서는 신재와 도장이 제거된 범퍼 분쇄품을 일정 비율 혼합하여 혼합비에 따른 기계적인 물성 및 화학적인 성질을 연구하였다. 신재에 범퍼 분쇄 품을 혼합하였을 때 인장강도 및 굴곡탄성율과 같은 강성은 두 물질의 조성 평균으로 나타났지만, 충격강도와 파단 신율과 같은 인성 (toughness)은 조성 평균보다 낮은 negative deviation을 보였다. 이는 두 물질간의 혼화성이 부족하여 발생하는 결과라는 것을 FT-IR 분석을 통하여 알 수 있었다. 범퍼 분쇄품의 혼합 비율이 30% 이상에서 두 물성이 급격히 저하되었다. 이를 활용하면 최적의 배합 비율을 선정할 수 있을 것이다. 또한 이전 연구에서 밝힌 바와 같이 도장 제거율을 80 % 수준까지는 달성하기는 쉽지만 나머지 20%를 제거하기 위하여 많은 노력과 에너지가 소요되는 바, 도장이 제거되지 않은 분쇄품과 도장이 제거된 분쇄품의 혼합 비율에 따른 기계적인 물성에 대하여 실험하였다. 도장이 제거되지 않은 범퍼 분쇄품이 소량만 첨가되어도 기계적인 물성은 급격히 저하가 되어 폐 범퍼를 재활용하기 위해서는 도장 제거 공정이 매우 중요하다는 사실을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1366-1369
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• 2003

Today, the industries use polymer material for many purpose. Specially, it is important in automobile industry because tile costs of polymer hold high proportion of the overall cost. If we reduce the weight of automobile, fuel efficiency of car is raised and cost of bumper is lower. Therefore there are many efforts to reduce of car currently. The purpose of this paper is to reduce polymer used in car bumper.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1724-1727
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• 2005

Injection molding process is one of the processes that can mold plastic product as low cost. However, manufacturing process of automobile bumper mold has lots of trial and error. Especially, desiging of a huge mold such as bumper mold is needed to establish a design standard for runner system. In this study, CAE was conducted to observe the variation of melt-flow by changing runner and gate type in automobile bumper mold as preceding study for a standard design of runner system.

• 한국기계가공학회지
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• 제17권3호
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• pp.28-33
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• 2018

The automotive front bumper guard is the most important part of the vehicle for protecting the life of driver when a traffic accident happens. In order to ensure safe driving, this part must possess sufficient strength and durability. This study was carried out with structural and fatigue analyses by designing front bumper guard models. After the lowest value for maximum total deformation and equivalent stress was found through structural analysis and the highest value for fatigue life was found for all three models, it was shown that the type C front bumper guard model was the most suitable for application to a real car. The strength property and durability of the optimum design were determined through this study's results.

• 한국기계가공학회지
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• 제19권8호
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• pp.1-7
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• 2020

In this study, three models on the installation of automotive additional front bumper guard were designed and the structural analysis was carried out. The additional front bumper models B and C appears to be safer on stability instead of the basic front bumper model A. Model A with a simple structure is shown to have the safe region overall except in the area where the load is applied directly. Models B and C are shown to have the shortest lives at the regions where the bumpers are connected with each other. By comparing with the least fatigue lives at models A, B and C, Model B has the longest life with the best durability.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.295-298
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• 1997

Recycl ing of PP/EPR based bumper coated with polyester urethane paint has been per formed by chemical decoating method. Electronic Speckle Pattern Interferometry (ESP11 has been applied to characterize the deformation of polyolef in based bumper. In additon, physical properties and processability of recycled materials have been investigated by dynamic mechanical thermal analysis, impact test and melt flower index measurement. The results show that the deformation ratio of recycled material is higher than that of virgin one. The morphological change of EPR, degree of distribution and dispersion during the recycling process seem to be the most important factor for the deformation and the mechanical properties of recycled materials. The experimental results obtained show that ESPI is very powerful technique to study the thermal mechanical property of polyolefin bumper system.

• 자동차안전학회지
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• 제6권2호
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• pp.5-11
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• 2014

Front side member of the front impacted vehicle plays a key role in minimizing the impacting load transferred to the compartment. To perform that required function, axial collapse should be dominant during side member crashing and, prior to designing side member, it is crucial to minimize bending moment occurred at the front end. In this study, for FE model of a SUV front body, front impact analyses were carried to find out bumper stay design which effectively develope axial collapse in the side member. As a previous work, the thickness of side member reinforcement were changed. Next, the inner thickness of bumper stay was increased. Also, the bead shape and location were modified. Final front body model showed much more axial collapsed mode and enhanced crash performance. In addition, a stay of octagon section was adopted and that model exhibited distinctive increase in impact energy absorption.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.30-33
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• 2005

Although extruded aluminium bumper beam has been commonly used in advanced car makers, there are not so much precedent for it's localization. For the localization of aluminum bumper beam of 7XXX series, benchmarking, material modifications of 7XXX series aluminum alloy, section design of beam, impact analysis had been performed in this study. High fuel efficiency and weight reduction could be achieved by using aluminum bumper beam of which the weight is lighter than that of steel. Moreover, it is expected to reach higher recycling rate by substituting aluminum for steel.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권4호
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• pp.273-279
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• 2017

Purpose: Recently, Issues on security for vehicles are getting increased all around the world. Especially, hood panel needs to be thinner for the protection of pedestrians. But thinner panel makes durability get worse. So, it is needed to satisfy both of them. Methods: Durability effectiveness will be studied because properties and assembly allowance of over-slam bumper mostly affects durability of hood panel. Overlap of over-slam bumper can be made in production line and it can affect durability of spot welding in hood inner panel. Daguchi method is used to catch the condition in which load gets smaller and location, hardness and quantity of overlap are selected to be factors. Durability effectiveness is analyzed with the factors. Result: the mechanism that affects on spot welding is identified. The test was conducted in both open/close and driving condition and the relation between both conditions is analyzed. Conclusion: The test contributed to durability of hood panel with optimization of over-slam bumper.