• Title/Summary/Keyword: 정적압궤

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A Study on the Static Collapse Characteristics of CFRP Side Member for Vehicle (차체구조용 CFRP 사이드부재의 정적 압궤특성에 관한 연구)

  • Lee, Kil-Sung;Yang, In-Young
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.83-86
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    • 2005
  • The front-end side members of automobiles, such as the hat-shaped section member, absorb most of the energy during the front-end collision. The side members absorb more energy in collision if they have higher strength and stiffness, and stable folding capacity (local buckling). Using the above characteristics on energy absorption, vehicle should be designed light-weight to improve fuel combustion ratio and reduce exhaust gas. Because of their specific strength and stiffness, CFRP are currently being considered for many structural (aerospace vehicle, automobiles, trains and ships) applications due to their potential for reducing structural weight. Although CFRP members exhibit collapse modes that are significantly different from the collapse modes of metallic materials, numerous studies have shown that CFRP members can be efficient energy absorbing materials. In this study, the CFRP side members were manufactured using a uni-directional prepreg sheet of carbon/Epoxy and axial static collapse tests were performed for the members. The collapse mode and the energy absorption capability of the members were analyzed under the static load.

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Collapse Characteristics of CFRP Hat Shaped members According to Variation of Interface Numbers under the Hygrothermal Environment (고온.고습 환경 하에서의 계면수 변화에 따른 CFRP모자형 단면 부재의 압궤특성)

  • Yang, Yong-Jun;Cha, Cheon-Seok;Yang, In-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.3
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    • pp.241-247
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    • 2009
  • It is important to satisfy the requirements and standards for the protections of passengers in a car accident. There are lots of studies on the crushing energy absorption of a structure members in automobiles. We have studied to investigate collapse characteristics and moisture absorption movements of CFRP(Carbon Fiber Reinforced Plastics) hat shaped sectional members when CFRP laminates are under the hygrothermal environment. In particular, the absorbed energy, mean collapse load and deformation mode were analyzed for side members which absorbed most of the collision energy. Variation of CFRP interlaminar numbers is important to increase the energy absorption capability. Therefore we have made a static collapse experiment to research into the difference of absorbed energy and deformation mode between moisture absorbed specimen and non-moisture absorbed.

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Collapse Characteristics of CFRP Hat Shaped Members under the Hygrothermal Environment According to Stacking Angle (열습환경 하에서의 적층각도 변화에 따른 CFRP 모자형 단면부재의 압궤특성)

  • Yang, Yong-Jun;Yang, In-Young;Sim, Jae-Ki
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.5
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    • pp.507-513
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    • 2009
  • It is important to satisfy the requirements and standards for the protections of passengers in a car accident. There are lots of studies on the crushing energy absorption of structure members in automobiles. We have investigated collapse characteristics and moisture absorption movements of CFRP(Carbon Fiber Reinforced Plastics) hat shaped sectional members when CFRP laminates are under the hygrothermal environment. The absorbed energy, mean collapse load and deformation mode were analyzed for side members which absorbed most of the collision energy. Therefore we have made a static collapse experiment to research into the difference of absorbed energy and deformation mode between moisture absorbed specimen and non-moisture absorbed specimen.

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Strength Evaluation of CFRP Hat-shaped Sectional Members Due to Variation of Collapse Conditions Under Hygrothermal Environment (고온.고습 환경하에서의 압궤조건 변화에 따른 CFRP 모자형 단면부재의 강도평가)

  • Yang, Yong-Jun;Yang, In-Young;Sim, Jae-Ki
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.1
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    • pp.7-14
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    • 2012
  • CFRP composite material has the superior specific strength and rigidity compared to metallic materials, and is widely adopted in the various fields. However, CFRP composite material has the weakness in hygrothermal and crash environment. Especially, moisture ingress into composite material under hygrothermal environment can change molecule arrangement and chemical properties. In addition, interface characteristics and material component properties can be degraded. A collapse experiment has been made to research the differences of absorbed energy and deformation mode between absorbed specimens of moisture and non-moisture. As a result of this study, the effect of moisture absorption and impact loads of about 30~50% reduction in strength are shown.

Energy Absorbing Characteristics of Thin-Walled Members for Vehicles Having Various Section Shapes (차체구조용 박육부재의 단면형상변화에 따른 에너지흡수 특성)

  • 차천석;정진오;이길성;백경윤;양인영
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.177-182
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    • 2003
  • The front-end side members of automobiles absorb most of the energy in a case of front-end collision. The front-end side members are required to have a high stiffness together with easiness to collapse sequentially to absorb more impact energy. The axial static collapse test (5mm/min) was conducted by using UTM for form different types of members which have different cross section shapes; single hat, single cap, double cap, and double hat. The single hat shaped section member has the typical standard section, which the double hat shape section has a symmetry in the center to have more stiffness. As a result of the test, the energy absorbing characteristic was analyzed for different section shapes. It turned out that the change of section shape influence the absorbing energy, the mean collapse load and the maximum collapse load, and the relation between the change of section shape and the collapse mode.

Collapse Characteristics on Width Ratio and Flange Spot-Weld Pitch for Hat-Shaped Members (모자형 단면부재의 폭비와 플랜지 용접간격에 따른 압궤특성)

  • Cha, Cheon-Seok;Gang, Jong-Yeop;Kim, Yeong-Nam;Kim, Jeong-Ho;Kim, Seon-Gyu;Yang, In-Yeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.1
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    • pp.98-105
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    • 2001
  • The fundamental and widely used spot welded sections of automobiles (hat and double hat-shaped section members) absorb most of the energy in a front-end collision. The sections were tested on axial static(10mm/min) and quasi-static(1000mm/min) loads. Based on these test results, specimens with various thickness, shape and spot weld pitch on the flange have been tested with impact velocity(7.19m/sec) the same as a real life car clash. Characteristics of collapse have been reviewed and a structure of optimal energy absorbing capacity is suggested.

A Study on Axial Collapse Characteristics of Spot Welded Double-Hat Shaped Section Members by FEM (FEM에 의한 점용접된 이중모자형 단면부재의 축방향 압궤특성에 관한 연구)

  • Cha, Cheon-Seok;Kim, Young-Nam;Yang, In-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.7
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    • pp.120-126
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    • 2001
  • The widely used spot welded section members of vehicles are structures which absorb most of the energy in a front-end collision. In front-end collision, sufficiently absorbed in the front parts, the impact energy does not reach the passengers. Simultaneously, the frame gets less damaged. This structures have to be very stiff, but collapse progressively to absorb the kinetic energy as expected. In the view of stiffness, the double-hat shaped section member is stiffer than the hat shaped section member. In progress of collapse, the hat shaped section member is collapsing progressively, but the double-hat shaped section member does not due to stiffness. An analysis on the hat shaped section member was previously completed. This paper concerns the collapse characteristic of the double-hat shaped section member. In the program system presented in this study, an explicit finite element code, LS-DYNA3D is adopted for simulating complicate collapse behavior of double hat shaped section members with respect to spot weld pitches. And comparing with the results from the quasi-static and impact experiment, the simulation has been verified.

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Strength Evaluation on CFRP Hat-shaped Sectional Members According to Changes in Temperature Under Hygrothermal Environment (온도 변화에 따른 열습 환경하에서의 CFRP 모자형 단면부재의 강도평가)

  • Yang, Yongjun;Kook, Hyun;Yang, Inyoung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.6
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    • pp.892-896
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    • 2012
  • CFRP composites with light weight, high strength, and high elasticity by comparing with metal are widely used rather than previous steel plates. However, CFRP composite material has the weakness at hydrothermal and collapsed impact environment. Especially, moisture absorption into composite material can change molecule arrangement and chemical properties under hydrothermal environment. And static collapse experiment is the research in the differences of absorbed energy and deformation mode between moisture and non-moisture absorbed specimens. This study is compared and analyzed on the progress change of moisture absorption ratio after setting up the temperatures of 60 and 80 degrees C in order to comprehend how the change in the temperature influences on moisture absorption status inside CFRP composite materials.

Energy Absorption Characteristics of the Al/CFRP/GFRP Hybrid Member under Quasi-static Axial Compressive Load (준정적 축 압축하중을 받는 Al/CFRP/GFRP 혼성부재의 에너지흡수 특성)

  • Kim, Sun-Kyu;Heo, Uk;Im, Kwang-Hee;Jung, Jong-An
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.4
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    • pp.588-592
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    • 2012
  • This study concentrates the effect of hybridisation on the collapse mode and energy absorption for composite cylinders. The static collapse behavior of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell under quasi-static axial compressive load has been investigated experimentally. Eight different hybrids of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell were fabricated by autoclave. Eight types of composites were tested, namely, Al/carbon fiber/epoxy, Al/glass fiber/epoxy, Al/carbon-carbon-glass/epoxy, Al/carbon-glass-carbon/epoxy, Al/carbon-glass-glass/epoxy, Al/glass-glass-carbon/epoxy, Al/glass-carbon-glass/epoxy and Al/glass-carbon-carbon/epoxy. Collpase modes were highly dominated by the effect of hybridisation. The results also showed that the hybrid member with material sequence of Al-glass-carbon-carbon/epoxy exhibited good energy absorption capability.