• 제목/요약/키워드: Absorbed Energy per Unit Volume

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경량화용 박육부재의 형상비가 압궤특성에 미치는 영향 (Influence of dimensional ratio on collapse characteristics for the thin-walled structures of light weight)

  • 정종안;김정호;양인영
    • 한국안전학회지
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    • 제13권3호
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    • pp.11-23
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    • 1998
  • In this study, collapse test of thin-walled structure is performed under axially quasi-static and impact load in collapse characteristic to develop the optimum structural member for a light-oriented automobile. Furthermore, the energy-absorbing capacity is observed according to the variety of configuration(circular, square), aspect ratio in aluminum specimen to obtain basic data for the improved member of vehicle. In both quasi-static and impact collapse test, Al circular specimens collapse, in general, with axisymmetric mode in case of thin thickness while collapse with non-axisynmetric mode according to the thickness increase. For Al rectangular specimens, they collapse with axisymmetric mode in case of thin thickness, with mixed collapse mode according to the increase of thickness. In terms of initial max. load, Al square specimen turns out the best member among specimens, and then Al square, circular and circular with large scaling ratio, respectively. In case of quasi-static compression test, the absorbed energy per unit volume and mass shows higher in Al circular specimen, and then Al square, circular with large scaling ratio, respectively, according to shape ratio the absorbed energy per unit volume and mass in case of max. impact compression load is higher than that of static load. But the absorbed energy per unit volume and mass shows that Al circular specimen is the best member. Especially, unlike max. compression loan, the absorbed energy per unit volume and mass in impact test turns out the low value.

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탄소섬유강화 복합재 적층판의 충격파괴 특성에 관한 연구 (A Study on Characteristics of Impact Fracture in CFRP Laminate Plates)

  • 양인영;정종안
    • 한국자동차공학회논문집
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    • 제3권5호
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    • pp.38-46
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    • 1995
  • In this paper, an experimental study on the effects of the impact damage and the perforation characteristic of CFRP laminates with different fiber stacking orientation and ply number was done through an observation of interrelations between the impact energy vs. transmitted energy and the impact energy vs. absorbed energy per unit volume. The velocities of the ball before or after impact are measured by the high-speed camera. And when CFRP laminates are subjected to tranverse impact by a steel ball(${\phi}10$), the delamination shapes generated by impact damage are observed by using SAM (Scanning acoustic Microscope).

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ENERGY ABSORPTION CHARACTERISTICS IN SQUARE OR CIRCULAR SHAPED ALUMINUM/CFRP COMPOUND TUBES UNDER AXIAL COMPRESSION

  • CHA C. S.;LEE K. S.;CHUNG J. O.;MIN H. K.;PYEON S. B.;YANG I. Y.
    • International Journal of Automotive Technology
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    • 제6권5호
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    • pp.501-506
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    • 2005
  • With the respective collapse characteristics of aluminum and CFRP (Carbon Fiber Reinforced Plastics) tubes in mind, axial collapse tests were performed for aluminum/CFRP compound tubes, which are composed of square or circular shaped aluminum tubes wrapped with CFRP outside. In this study, the collapse modes and the energy absorption characteristics were analyzed for aluminum/CFRP compound tubes which have different fiber orientation angle of CFRP. Fracture modes in the aluminum/CFRP compound tubes were rather stable than those in the CFRP tubes alone, probably due to the ductile nature of the inner aluminum tubes. The absorbed energy per unit volume of the aluminum or the aluminum/CFRP compound tubes was higher than that of CFRP tubes. Meanwhile, the absorbed energy per unit mass, for the light-weight design aspect was higher in the aluminum/CFRP compound tubes than in the aluminum tubes or the CFRP tubes. The energy absorption turned out to be higher in circular tubes than in square tubes. Beside the collapse modes and the energy absorption characteristics were influenced by the orientation angle, and the compound tubes took the most effective energy absorption when the fiber orientation angle of CFRP was 90 degrees.

고온 고습하에서 CFRP 적층 원통부재의 충격 압궤특성 (A study on impact collapse characteristics of CFRP thin-walled laminates under high temperatures and hygrothermals)

  • 김정호;곽훈이;양인영
    • 한국안전학회지
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    • 제13권2호
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    • pp.30-38
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    • 1998
  • In this study, in order to measure energy-absorbing characteristics in impact test of CFRP thin-walled laminates and interpret the cause of decreasing age when collapse test is carried out under the environments of high temperatures and hygrothermals, the moisture absorbing behavior according to the variety of orientation angle is observed and impact collapse characteristics of no moisture absorbing status is compared with that under the environments of high temperatures and hygrothermals. Especially, we try to obtain quantitative design data to develop CFRP thin-walled laminates with energy characteristics of optimum impact absorbing. The value of the maximum loading, mean loading, rate of energy absorption energy per unit volume and mass in CFRP thin-walled laminates on the high temperatures and hygrothermals is measured much lower than under no moisture absorbing. The maximum collapse loading in dynamic impact test is taken measurements lower than in static collapse test CFRP circular laminates in high temperatures and hygrothermals. But the absorbed energy per unit mass and volume is almost same each other and the biggest amount of energy is shown in CFRP circular laminates with orientation angle of $15^{\circ}$. Therefore, in the case of using CFRP circular laminates with axisymmetric mode, CFRP thin-walled structural members with orientation angle of $10^{\circ}$, $15^{\circ}$ has generally best condition.

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고온 .senter dot. 고습환경이 CFRP 적층 원통부재의 압궤특성에 미치는 영향 (Effects of high temperatures and hygrothermals on the collapse characteristics of CFRP thin-walled laminates)

  • 곽훈이;김정호;양인영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.650-654
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    • 1995
  • In this study, in order to measure energy-absorbing charactistics in collapse test of CFRP thin-walled laminates and interpretate the cause of decreasing age when collapse test is carried out under the environments of high temperatures and hygrothermals, the moisture absorbing behavior according to the variety of orientation angel is observed and collapse characteristics is compared with the influence of high temperatures and hygrothermals. Especially, we supposed to clearly understand reationship between collapse characteristics in proportion to the variety of orientation angel and moisture absorbing. The value of the maximum loading, mean loading,rate of energy absorption energy per unit volume and mass in CFRP thin-walled laminates on the high temperatures and hygrothermals is measured lower than under no moisture absorbing. The maximum collapse loading in dynamic impact test is taken measurement lower than in static collapse test regarding compared with collapse characteristics conformity with the variety of the CFRP circular laminates in high temperatures and hygrothermals. But the absorbed energy per unit mass and volume is almost same and the biggest amount of energy is shown in the CFRP circular laminates with orientation angel of 15 .deg.. Therefore, in the case of use to CFRP circular laminates with axisymmetric mode, CFRP thin-walled structal members with orientation angel of 10 .deg. , 15 . deg. are generally useful.

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국산 소경재의 휨 성질을 이용한 충격에너지와 최대하중까지 일-에너지 예측연구 (Study on the Prediction of the Work-Energy to the Maximum Load and Impact Bending Energy from the Bending Properties)

  • 차재경
    • 한국가구학회지
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    • 제19권5호
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    • pp.350-357
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    • 2008
  • This research investigates the bending properties to predict the work-energy to maximum load and impact bending energy from static bending and impact bending test. Specimens were prepared from lumber made of thinning crop-trees. Matched specimens were used for MC 12% and green moisture specimens to measure the effect of moisture content on the absorbed energy from static and impact bending tests. The bending properties such as MOE, MOR, etc. is a good predictor to investigate the work-energy and work-energy per unit volume from static bending and impact bending test. The impact bending energy is increased with increasing moisture content. However, the work to maximum load from static bending test is increasing with increasing the MC only for higher density species.

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