• Title/Summary/Keyword: 낙하 시험

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Drop Impact Analysis of Outside Cooling Unit Package of System Air-Conditioner and Experimental Verification (시스템 에어컨 실외기 포장품의 낙하충격해석 및 시험적 검증)

  • Kim, Hyung-Seok;Lee, Boo-Yoon;Lee, Sanghoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.111-116
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    • 2018
  • This research examines the drop impact of an external cooling unit package of an air conditioner system. The packaging is composed of a shock-absorbing material, which protects the package contents by absorbing the impact energy and other parts for fixture. Accurate quantification of the impact acceleration experienced by the package contents is necessary to design an effective packaging with minimal volume and sufficient shock absorbing capacity. Explicit time integration was used for the drop impact analyses. A finite element model of the package was constructed, material testing and material model selection were carried out, and sensors for data acquisition were modeled to obtain accurate simulation results. The results were compared with real physical test data. Due to imprecise modeling of the damping, the acceleration and strain values predicted by the simulation were larger than those from physical test. However, the trend of the history data and the peak deceleration value in the direction of impact showed good agreements. Thus, the analysis model and scheme are suitable for the design of an air conditioner cooling unit package.

Numerical Study of Drop/impact test and Shock/impact Survivability Test for ELT(Emergency Locator Transmitter) Operations (ELT(Emergency Locator Transmitter) 운용을 위한 낙하 충격 및 추락생존성 시험에 대한 수치 해석적 연구)

  • Jung, Do-Hee;Baek, Jong-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.12
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    • pp.1229-1235
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    • 2008
  • ELT(emergency locator transmitter) has assisted in the rescue of thousands of lives in distress. Aviators, mariners and land users being equipped with distress beacons are capable of transmitting distress signals to the satellites in emergency situations anywhere in the world. In this paper, Drop/Impact simulation was performed for ELT Body-case. FE model for Body-case was constructed with MSC/Dytran and refined using the Karas example simulation for Body-case prototype. Shock/impact survivability analysis was performed for ELT operations. FE model constructed with MSC/Nastran. Transient response analysis for refined ELT model was perfomed for ELT under impact shock loading condition.

Safety Evaluation of a Shipping Capsule for Special Form Radioisotope (특수형 방사성 동위원소 운반캡슐의 안전성 평가)

  • Lee, Ju-Chan;Seo, Ki-Seog;Ku, Jeong-Hoe;Bang, Kyoung-Sik;Han, Hyon-Soo;Park, Seong-Won
    • Journal of Radiation Protection and Research
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    • v.26 no.1
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    • pp.35-43
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    • 2001
  • All of sealing capsules to transport a special form radioactive material should be designed and fabricated in accordance with the design criteria prescribed in IAEA standards and domestic regulations. The objective of this study is to demonstrate the safety of a shipping capsule for $^{192}Ir$ special form radioisotope which produced in the HANARO. The safety tests were carried out for the impact, percussion, bending and heat test conditions. And leakage tests were carried out before and after the each test. Also, the safety analyses wert performed using computer codes in order to verify the test results. The capsule showed slight scratches and deformation, and maintained its structural and thermal integrities in all tests without any severe damage or melting. It also met the allowable limits of leakage rate after each test. Therefore, it has been verified that the capsule was designed and fabricated to meet all requirements for the special form.

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A Study on Strength Evaluation of LCD Glass for Drop test (액정 디스플레이(LCD) 낙하 충격해석에 관한 연구)

  • Joung, Jae-Hak;Kim, Han-Ba-Ra;Seong, Young-Ho;Choi, Hyun-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.10
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    • pp.99-108
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    • 2007
  • As the structure of a mobile phone becomes thin to catch up with a slim product trend, the reliability of a LCD module is on the rise as a big issue for a product design. A drop test is the most basic and important verification method for a mechanical quality control but it requires much time and cost during a product development process. Thus many manufacturers have considered design guide lines using CAE and simulation for more effective usage of limited resources on the market. In this paper, the Maximum Principle Stress of a LCD glass panel is calculated on the basis of explicit FE Analyses method and input conditions are determined according to the general test standard. The design guideline for reliability improvements are suggested on the basis of the results of FE Analysis.

A Study on Impact Damage Characteristics of the Window Glass for High Speed Train (고속열차 객실 유리창 충격파손특성 비교 연구)

  • Jeon, Chang-Sung;Kim, Young-Guk;Yun, Su-Hwan;Kwon, Hyeok-Bin;Park, Tae-Won
    • Journal of the Korean Society for Railway
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    • v.15 no.3
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    • pp.217-223
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    • 2012
  • This study describes an experimental investigation about the impact damage characteristics of various types of high speed train window glass. Kinds of impact test standards for glass were studied and impact test considering scattering ballast were developed. Windows with external impact side made with annealed, heat strengthened and tempered glasses are likely to be broken by sharp tipped falling object. Broken shape of annealed glass is like line in part and that of heat strengthened glass is line on the whole. Tempered glass is destroyed to pieces. The change of tip type from sharp to blunt makes the higher destroyed level. Tempered glass has higher strength than annealed glass with blunt tip. When the protective films are attached to glasses, strength against destruction increases. In case of real ballast test, glasses without protective films were destroyed, but those with protective films are hard to be broken.

Drop Test for the UAV Landing Gear Performance Verification (무인정찰기 착륙장치 성능입증을 위한 낙하시험)

  • Shin, Jeong-Woo;Lee, Seung-Gyu;Yang, Jin-Yeol;Kim, Sung-Joon;Hwang, In-Hee;Chung, Sang-Joon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.250-254
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    • 2011
  • Main role of landing gear is to absorb the energy which is generated by aircraft lanidng and ground maneuvering. Generally, in order to absorb the impact energy during landing, oleo-pneumatic type shock absorber is used for aircraft landing gear. Oleo-pneumatic type shock absorber has a good energy absorbing efficiency and is light in weight because its structure is relatively simple. For the landing gear development, it is necessary to conduct drop test in order to verify shock absorbing performance. In the drop test, first, gas spring curve verification tests are conducted. Then, limit and reserve energy absorption drop tests are performed based on the STANAG 4671. The drop tests results with performance analysis results are presented.

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The Operation of Flight Safety Center for KSLV-I Third Flight Test (KSLV-I 3차 비행시험에서의 비행안전통제실 운영)

  • Choi, Kyu-Sung;Sim, Hyung-Seok;Ko, Jeong-Hwan;Rho, Woong-Rae
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.182-188
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    • 2013
  • This paper described flight safety center, flight safety information system(FSIS) and flight safety officer's mission and training in sequence and presented analysis's results and data processed in real-time during KSLV-I 3rd flight test. During flight safety center's operation for the 3rd flight test, monitoring of KSLV-I flight status was normally performed and the algorithms for flight safety calculations including the one for instantaneous impact point computations are also executed normally.

Susceptibility of Pine Wood Nematode Vectors to ULV Insecticides Sprayed from an Unmanned Helicopter (무인항공기를 활용한 유인항공기용 작물보호제에 대한 소나무재선충 매개충의 약제 감수성)

  • Kim, Junheon;Nam, Sangjune;Song, Jinyoung
    • Korean journal of applied entomology
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    • v.59 no.2
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    • pp.83-91
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    • 2020
  • We assessed efficacy of spraying pesticides from an unmanned helicopter to control two insect species, Monochamus alternatus and M. saltuarius, which are vectors of pine wood nematodes. Control efficacy of thiacloprid FL (33×), acetamiprid ME (33×), and flupyradifurone SL (33×) was determined by placing caged insects in the canopy of pine trees (Pinus sp). Water-sensitive paper was used to record the spray pattern of pesticide droplets and the degree of coverage; furthermore, we investigated peripheral scattering due to spraying. The three pesticides showed > 96% control efficacy against the targeted vectors, and pesticide droplet spray patterns were similar. Peripheral scattering was observed up to 20 m in front and 10 m to the left, right, and behind the targeted area. The coverage index of all the directions at 5 and 10 m distance was 6-7 and 2, respectively.