• Title/Summary/Keyword: 낙하충격해석

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Shock Simulation and Experimental Verification of HDD (하드디스크 드라이브의 충격해석 및 실험적 검증)

  • Kim, Jin-Gon;Lee, Jae-Kon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2583-2588
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    • 2009
  • This study deals with the shock response analysis of HDD subjected to a half-sine shock pulse and its experimental verification. Comparatively, accurate computer simulation allows designers to determine complete mechanical information during the product impact time period, compared with only segmental messages by sensors in a test, to predict potential failures. But, impact/shock simulation technology is rather sensitive to various factors to predict the shock behavior without validation. In our shock simulation, the methodology of analysis with LS-DYNA3D and test validation is adopted to predict the shock behavior of HDD. We can confirm the soundness of the present shock simulation through the comparison with electromagnetic shock test(200G/1ms) and linear drop test(300G/2ms).

Structural Design and Crashworthiness Analysis of Fuselage Frame for Ultralight Aircraft (초경량 항공기 프레임 동체의 구조 설계 및 내충격 해석)

  • HeeSung Lee;Juho Lee
    • Journal of Aerospace System Engineering
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    • v.18 no.4
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    • pp.61-69
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    • 2024
  • With increasing interest in aviation leisure sports, the demand for ultralight aircraft has increased, highlighting the necessity for robust structural design of the aircraft. In response, this study conducted static structural analysis and free-fall analysis of fuselage frame of ultralight aircraft. Robust design and crashworthiness under operational load conditions and vertical impact scenarios were evaluated by assessing maximum stress and safety factors. Analyses were performed using finite element method-based software ANSYS Workbench. Results including stress distribution and strain were analyzed to verify the safety of the designed fuselage frame. Additionally, this study predicted excessive deformation and failure locations of the fuselage frame during vertical drop impacts.

Effects of Cavitation and Drop Characteristics on Oleo-Pneumatic Type Landing Gear Systems (공동현상을 고려한 유공압 방식 착륙장치의 낙하특성에 관한 연구)

  • Han, Jae-Do;Lee, Young-Sin;Kang, Yeon-Sik;Ahn, Oh-Sung;Kong, Jeong-Pyo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.2
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    • pp.193-200
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    • 2009
  • This paper investigated the drop characteristics of oleo pneumatic type landing gear for small aircraft and the effects of cavitations in modeling the landing gear system. The landing gear system employed a simple oleo pneumatic type damper without a metering pin. In general, oleo-pneumatic type landing gears are light-weighted because of it's simplicity, yet they offer excellent impact absorption characteristics. In this study, the landing gear system was modeled using MSC ADAMS, which offers a drop simulation module. After modeling the system, a series of testing was conducted, using a prototype landing gear system, to validate the analysis model and simulation results. The effect of cavitation was considered in the simulation model to obtain a better correlation between the test and simulation results. The results show that adding the cavitation effect in the simulation model significantly improved the simulation model and better captured the dynamic behaviors of the landing system. Using the 'cavitation' model, dynamics characteristics of the landing gear were further evaluated for other landing conditions, such as landing in various angles of slopes.

Drop Test for Landing Gear with Rubber Spring Shock Absorber (러버 스프링 방식 착륙장치 낙하시험)

  • Jung, Seung-Tack;Lee, Seung-Gyu;Yang, Jin-Yeol;Lee, Sung-Jin;Kim, Sung-Chan;Song, Jung-Heon
    • Proceedings of the KAIS Fall Conference
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    • 2011.12b
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    • pp.631-634
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    • 2011
  • 항공기용 착륙장치의 완충기 충격흡수 성능은 해석 과정을 거쳐 예측한 값과 낙하시험을 수행하여 그 성능을 입증하여야 한다. 이는 미 연방 항공 규정에서 요구하고 있는 사항이다. 본 논문에서는 착륙장치 낙하시험을 위한 설비, 시험절차 및 시험방법과 낙하시험 수행 결과를 제시한다.

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Design of Standard Jigs for Drop Tests of OLED Modules (OLED 모듈의 충격시험용 표준 지그 개발)

  • Lee, Kwang-Ju;Kim, Min-Yeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2463-2469
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    • 2011
  • The failure of display modules in cellular phones due to drop impact depends on the materials, stiffnesses and shapes of the phones. In the early development stage of cellular phones, the behavior of the display modules due to drop impact is tested using jigs where the display modules are installed. In this study, jigs of cellular phones for drop impact test of OLED modules were designed. The material, thickness and number and orientation of ribs were considered as design variables. Jigs were designed in a way that responses of modules due to drop impact were similar to those of modules in cellular phones. The maximum principal stresses at the upper glasses of modules were considered as responses, which were analyzed using a commercial software ABAQUS/Explicit. The drop impact analysis at the height of 1.5 meters showed that the responses of OLED module in the developed jig were in a good agreement with those in cellular phone.

Analysis of Package Drop and its Application for Optical Disc Drives (광 디스크 드라이브용 완충포장재의 낙하충격 해석 및 활용)

  • 석기영;윤기원;나정민;박창배
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.177-182
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    • 2004
  • Electronic products are subjected to many different types of shock environment. As the Optical Disc Drive (ODD) market grows, the number of failures related to shock increases. Therefore, it is necessary to improve the performance of cushion package as well as the product design. Cushion materials such as expanded polystyrene are often used to protect electronic products from shock environment. In this paper, the drop analysis of the cushion package f3r optical disc drives was carried out with the explicit method of LS-DYNA and verified by the drop test. For the optimization of package, response surface approximation model was created using central composite design. As a result, cushioning performance was improved under the critical condition and practical design guidelines of cushion package were suggested.

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Drop-Impact Analysis and Design of a Package of a Microwave Oven (전자레인지 포장품의 낙하충격 해석 및 설계)

  • Kim, Won-Jin;Lee, Boo-Youn;Son, Byung-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.536-543
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    • 2009
  • Dynamic behaviour of a package of a microwave oven under the drop-impact conditions is evaluated by the finite element analysis and tests. PAM-CRASH software is used for the finite element analysis and the tests are performed according to the ISTA(International Safe Transit Association) specification. Results of the analyses are compared with those of the tests and accuracy is shown to be favourable. Under the drop-impact condition of the original design, severe deformation occurs and an improved design is proposed to reduce it. The approach presented in this research can be successfully applied to reduce costs and time required to develop new models of the microwave oven.

Crashworthy Design and Test of Landing Gear (착륙장치 내추락 설계 및 시험평가)

  • Kim, Tae-Uk;Lee, Sang-Wook;Shin, Jeong-Woo;Lee, Seung-Kyu;Kim, Sung-Chan;Hwang, In-Hee;Jo, Jeong-Jun;Lee, Je-Dong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.7
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    • pp.601-607
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    • 2012
  • The main function of a landing gear is to absorb the impact energy during touchdown. It it occasionally required for landing gear to have crashworthiness for improving survivability and safety in case of emergency landing. This paper introduces the design concept, performance analysis and drop test procedures for the development of the crashworthy landing gear. The shock absorbing ability and the crash behavior are proved by analyzing various sensor data and video clips from high speed camera recording during drop tests.

Comparison of the Free-Fall Impact Force Applied to a Multicopter PAV According to External Airbag Folding Method (외부 에어백 폴딩 방식에 따른 자유 낙하 충돌 시 멀티콥터형 개인용 항공기에 가해지는 충격력 비교)

  • Jang, Yoon Ho;Kim, Jeong
    • Journal of Aerospace System Engineering
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    • v.16 no.1
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    • pp.28-39
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    • 2022
  • With the development of small multicopter PAV (Personal Air Vehicle), it is necessary to develop safety-related devices for manned rotorcraft. In this study, we assumed that an external airbag can be installed in a small multicopter PAV, and using LS-DYNA's Airbag Folding Application, we performed a free-fall collision analysis by modeling the airbag shapes consisting or Roll, Zigzag, and Sigma. There was no significant difference in the final airbag deployment time of the three models. However, when it collides with the ground during deployment, the Sigma fold type external airbag had the fastest deployment speed, applying the most impact force to the PAV, while the Roll fold type external airbag applied the smallest impact force to the PAV.