• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.4
• /
• pp.1552-1558
• /
• 2011

In this paper, the automotive beam using aluminium foam is designed and the impact analysis is carried out. The analysis model is the beam of actual size with B- type section structure. At the frontal crash of low speed, ANSYS AUTODYN is used by predicting the behavior of deformation and its internal energy. By the use of 7075-T6 aluminum alloy, the weight is reduced as much as 55% than steel. The deformation at the bumper foam of aluminum is similar with that of steel and the impact energy reduction at aluminum is more than steel. The foam filled with aluminum as much as 50 % has more impact energy absorption than the completely filled aluminum foam.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.3
• /
• pp.1122-1127
• /
• 2011

A bumper beam plays the important role of absorbing the bulk of bumper impact energy, so it is extremely important to determine the bumper beam section during the initial stage of car development process. This paper uses the Intermediate Response Surface Models (IRSM) technique for the bumper beam section optimization. By using this method, the nonlinear impact force-deflection curve is changed to an approximated curve. This can avoid the excessive 3D nonlinear FEM analysis during the optimization process. Then, the accuracy of the IRSM models is examined by comparing their results with those of the 3D nonlinear FEM. Finally it is shown that the proposed approach is effective to design the 2.5mph vehicle bumper section.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.683-684
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.829-830
• /
• 2010

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.5
• /
• pp.968-972
• /
• 2007

The importance of bumper system lies not only in the styling of vehicles, but also in the protection of vehicles and pedestrians from reasonable impact. In this study, we proceed to search a method for efficient bumper system without using the impact test and the computer simulation to analyze the bumper system. In the process of the research, we proposed the each method that is used to search the shape that satisfy each regulations in first, because bumper's dimensions to satisfy 'vehicle protection' regulations and form's dimensions to satisfy ‘pedestrian protection' regulations are difficult to exist together. After that we proposed the calculate method and design algorithm that is used to search a reasonable point satisfying the two regulations together.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.885-886
• /
• 2010

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.6
• /
• pp.78-84
• /
• 2017

Consistent efforts have been made to reduce the weight of automotive parts by using lightweight materials. This has resulted in the replacement of conventional steels in car body structures with high-strength steels, and the current usage rate has reached 50%. This study examines the structural stiffness and energy absorption capability of bumper beams made of high-strength steels. New types of bumper beam cross sections are proposed.The structural stiffness and maximum bending force were computed via finite element analysis as about 25tons and 7.5tons/mm, and there were no significant differences among the proposedcross sections. Dynamic analysis was also carried out to investigate the energy absorption capabilities of the bumper beams, and the effects of materials and thickness reduction were analyzed. High-strength steel can be used to achieve weight reduction with comparable structural performance to conventional bumper beams.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.4
• /
• pp.381-393
• /
• 2001

The current traffic situation in Korea can be described as rapid change in traffic volume and diversity in vehicle size from compact cars to large trucks. W-beam barrier most widely used in Korea was found not to satisfy the stiffness requirement for the Koran impact condition of 14 ton-60Km/h-15deg. and it was too stiff for small vehicles impacting with more realistic speed to satisfy the safety of vehicle occupants. To develop a guardrail system satisfying the two contradicting goals, a thrie-beam guardrail system, which had the beam thickness of 3.2mm and rubber cushions, was conceived. Even though the height of the thrie-beam(450mm) is increased by 100mm as compared to that of W-beam (350mm), there was only 2% increase in the weight of the thrie-beam. The new thrie-beam barrier system could contain more wide range of vehicle bumper heights, and showed better performance in the viewpoint of stiffness and energy absorbing capability than the W-beam system. The impact performance was evaluated from a crash test. The developed thrie-beam guardrail system satisfied all applicable criteria for NCHRP 350 test designation 3-10.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.3
• /
• pp.313-325
• /
• 2001

Tubular bridge rail was developed to restrain and redirect a 14ton van-type truck. The developed bridge rail permits better visibility than concrete safety-shape bridge rail, and it has better structural adequacy than the existing steel and aluminum bridge rails in Korea. The new bridge rail consists of a tubular thrie beam(TTB) rail and a steel guard rail, which are connected to composite posts. The TTB shape provides both better containment of diverse bumper heights and more tight fit between the ends of bridge rail and roadside guardrails than the existing bridge rail sections currently used in Korea. Making composite post by filling concrete inside the steel pipe of the same size as are used for the roadside guardrail post was found to be more efficient in increasing the stiffness and ultimate strength than simply increasing the size of the steel pipe. The system was crash-tested for the impact condition of 14ton-80km/h-$15^{\circ}$, and it satisfied all evaluation criteria set forth in NCHRP Report 350 for a Test Level 4 safety appurtenance. Acceptable performances were obtained in computer simulations for the impact condition of S2.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.377-384
• /
• 2004

지구환경 문제가 대두되면서 자동차 경량화를 위한 재료의 고강도화는 필수적인데, 재료의 고강도화는 성형성의 감소를 야기한다. 이러한 문제점은 가공방법으로 해결할 수 있는데, 그 대표적인 것이 프레스 경화(Press Hardening)공정이다. 프레스 경화 공법이란 성형성이 좋은 고온$(900^{\circ}C)$에서 성형하면서 성형 중 프레스에서 고강도를 부설하는 공법이다. 프레스 경화 공정은 스웨덴의 SSAB자회사인 프라냐에서 1973년에 개발된 공법으로 초기에는 높은 경도가 필요한 산업용 설비 (톱 등)에 적용되다가 1990년대부터 Bumper와 Door Impact Beam등의 자동차 부품으로 개발을 하여 적용되기 시작하였으며, 현재 그 적용 영역을 보다 넓혀나가고 있는 상태이다. 본 발표에서는 프레스 경화 공정의 대표 부품인 범퍼 임펙트을 개발하기 위해 관련한 성능해석을 수행하였다. 수행한 결과에 의하면 기존 소재 대비하여 $30\%$이상 경량화가 가능함을 알수 있었다.