• 제목/요약/키워드: Crush

검색결과 327건 처리시간 0.033초

박판사각튜브의 압괴 특성 (Crush Characteristics of Thin-walled Rectangular Tube)

  • 이종선
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1998년도 추계학술대회 논문집
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    • pp.261-266
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    • 1998
  • In this study, crush characteristics of thin-walled rectangular tube is investigated. The stiffness of the element is obtained from analytical moment-rotation relationship and approximated load-deflection relationship of thin-walled rectangular tube. A computer program is developed for the large deformation analysis of frame. An incremental displacement method is used in the program and at each incremental stage, the stiffness matrix of the total structure is checked with the state each element for bending and compression.

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알루미늄 압출재의 붕괴 특성 및 축소모형을 이용한 충격 해석 기법 연구 (Collapse Characteristics of Aluminum Extruded Sections and Crash Analysis Using Half Scale Model)

  • 김범진;허승진;구정서;송달호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2001년도 추계학술대회 논문집
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    • pp.229-234
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    • 2001
  • The aluminum extruded sections are used to the light construction of the high speed rail vehicle structures. However, the research works on the crashworthy design of aluminum extruded sections are not published sufficiently. In this paper, the collapse characteristics of aluminum extruded sections are investigated by crush test and simulation. The scale model studies are also performed to predict the impact energy absorption characteristics of full scale model through axial crush test and simulation.

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섬유강화 복합재료 Box Tube의 Crush거동 (Crush characteristics of the laminated composite box tubes)

  • 강수춘;전완주
    • 오토저널
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    • 제13권5호
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    • pp.65-72
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    • 1991
  • This paper presents the results of static crushing test that was conducted to characterize the energy absorption and collapse characteristics of composite box tubes. Fifteen specimens were fabricated with woven fabric prepreg using [0/90] glass/epoxy and were autoclave cured. Quasistatic compression test was performed on them. Collapse mode and energy absorption capacity vary significantly as a function of the thickness and length of a square side of composite box tube.

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좌골신경 압좌 손상 후 전침 및 녹용 약침의 통증 감소와 신경 재생에 관한 실험적 연구 (The Experimental Study of Electroacupuncture and Cervi Pantortichum Cornu Pharmacopuncture on Pain Decrease and Nerve Regeneration after Crush Injury of Sciatic Nerve)

  • 안혜림;양미성;신미숙;최진봉;김선종
    • 한방재활의학과학회지
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    • 제19권1호
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    • pp.39-55
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    • 2009
  • Objectives : This study was designed to evaluate effects of electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture on pain and nerve regeneration after crush injury of sciatic nerve in rats. Methods : We divided the subjects into 5 groups : control group, acupuncture treated group, electroacupuncture treated group, Cervi Pantortichum Cornu pharmacopuncture treated group, electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture group. Hot plate test and degree of Substance P antibody in each group were observed at the 1st, 2nd, 3rd and 5th day. Sciatic function index and change of BDNF immunoreactivity had been estimated at the 7th, 14th, 21st day respectively. Atrophy of the gastrocnemius at the 21st day was observed. Results : All the experimental groups showed significant changes in hot plate test, degree of Substance P antibody, sciatic function index and change of BDNF immunoreactivity compared with control group. Especially, when electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture used together, results were more effective than other groups. Recovery of the gastrocnemius was also the same. Conclusions : It is suggested that electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture may play a significant role on pain decrease and nerve regeneration after crush injury of sciatic nerve in rats and these two treatments could be more effective when used together.

Animal Model for the Evaluation of Repair of Injured Inferior Alveolar Nerve with Nerve Growth Factor

  • Lee, Jae-Yoon;Park, Suhyun;Heo, Hyun-A;Pyo, Sung-Woon
    • Journal of Korean Dental Science
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    • 제6권2호
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    • pp.58-66
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    • 2013
  • Purpose: The inferior alveolar nerve (IAN) can be damaged as a result of minor oral surgical procedure such as third molar extraction or implant placement. Repair of the injured IAN involves difficulty of access, and research studies are limited to elucidating the process of regeneration by surgical methods. This study sought to establish the rabbit animal model to apply polymeric membrane functionalized with nerve growth factor after a crush lesion for the evaluation of nerve regeneration using the electrophysiologic method. Materials and Methods: The IAN of 2 adult male New Zealand white rabbits (4 nerves) were exposed bilaterally, and crush injury rendered by jeweler's forceps was applied. Nerve conduction velocity was examined electrophysiologically using electromyography before, after, and 4 weeks after the crush injury. To evaluate the regeneration, the pattern of action potential of IAN was recorded, and the characteristics of neurons were histologically observed. Result: After the crush injury, afferent activity decreased in the injured group. Electromyography could not be recorded after four weeks because tissues surrounding the injured nerve collapsed. Decrease in the mean number of axons was observed in the injured part with membrane. Conclusion: Despite the limited result, the present animal model study may provide a possible way to research on the methods of enhancing the recovery of nerve injuries in clinical situations. For clinically widespread acceptance, however, it should gain more consecutive and scientific evidences.

후미추돌사고의 유효충돌속도가 차량손상 및 승차자 상해에 미치는 영향에 관한 연구 (A Study on the Effect of Delta-V Based on Vehicle Damages and Injuries Subjected by Rear-End Collisions)

  • 강성모;안병준
    • 한국안전학회지
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    • 제23권2호
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    • pp.72-80
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    • 2008
  • In a case of an automobile collision, vehicle damage and injury of the driver and the passenger occur. The scale of the collision which is effected by the extent of vehicle damage and the injury of the passenger, depends on the delta-V. Based on the photograph interpretation o the actual case of accidents in the Seoul and the Incheon area, this study measured the depth of crush and calculated the delta-V. Through verifying the correlation of the depth of crush and the change of velocity, relative equation was evaluated and compared with the prior study results to prove that they are almost identical. Thus, the depth of crush can be used as an index of the degree of impact, which can be utilized as the change of velocity to evaluate the level of injury done to the passengers. However, the period of hospitalization and diagnostics claimed by the injured proves to have no correlation with the delta-V and the extent of vehicle damage, this is due to the non-objective way of diagnosis and the anamnesis of the injured. This study established the absolute limit harmlessness and the choosing limit harmlessness, allowing the appraisal for Yes or No of the injury or the harmlessness based on the prior studies. Moreover, utilizing the relative equation formed between the depth of crush and the delta-V, each case of collision was compared and evaluated in comparison to the limit harmlessness to prove that the 90.4% of the so-called 'claiming-to-be-injured' were exaggerating or fabricating.

알루미늄 허니콤의 충격 에너지 흡수 특성 예측 (Prediction to Shock Absorption Energy of an Aluminum Honeycomb)

  • 김현덕;이혁희;황도순;박정선
    • 한국항공우주학회지
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    • 제39권5호
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    • pp.391-399
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    • 2011
  • 본 연구의 목적은 알루미늄 허니콤의 충격에너지 흡수 특성을 예측하는 것이다. 알루미늄 허니콤은 가볍고 에너지 흡수효율이 뛰어나며, 우주환경에서도 사용 가능하여 달착륙선의 충격흡수장치로 사용되고 있다. 충격에너지 흡수용 허니콤의 설계를 위해서는 에너지 흡수 과정에서 일정하게 유지되는 압축강도(crush strength)의 예측이 중요하다. 본 연구에서는 유한요소법을 이용하여 허니콤의 형상 및 충돌속도에 따른 압축강도를 예측하였다. 유한요소해석 프로그램은 Ls-dyna를 이용하였으며, 효율적인 유한요소 해석을 위하여 허니콤의 단위 셀 모델을 선정하였다. 이를 바탕으로 충돌속도 및 허니콤 포일(foil)의 두께 변화, 허니콤의 분기각(branch angle)에 따른 유한요소해석을 수행하여 에너지 흡수 특성을 분석하였다.