• Title/Summary/Keyword: Environment Vibration

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A Study on the Vibration Transmission Property of Automotive Air Conditioning Assembly by Frequency Response Analysis (주파수 응답해석을 이용한 자동차용 에어컨 라인 어셈블리의 진동전달 특성에 관한 연구)

  • Han, Seong-Ryeol;Kwak, Jae-Seob
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.3
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    • pp.48-53
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    • 2013

  • An automotive air conditioning assembly consists of a condenser, a compressor and an evaporator. These major components are connected with rubber hoses and aluminum pipes. Once mounted on the automotive air conditioning assembly, it is exposed to a serious vibration environment for a long time. In some cases, there are vibration cracking on the assembly. In order to solve this vibration problem, several real vibration tests are performed on the assembly of which the lay-out was optimized, in spite of sample production cost and making time. In this study, a frequency response analysis, which is a kind of finite element method of the vibration, was performed to know the characteristic of the vibration transmission on the assembly lay-out. The analysis result indicated the damping performance, which is satisfied with the vibration standard of car maker, in rubber hoses and the whole assembly.

  • KSCI

Ethylene Production of Packaged Apples under Vibration Stress in Simulated Transportation Environment

  • Jung, Hyun-Mo;You, Young-Ok
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.2
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    • pp.97-101
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    • 2017

  • Fruits are subjected to a variety of vibration stress during the transportation from a production area to markets. Vibration inputs are transmitted from the transporting vehicle through the packaged fruit. And the steady state vibration input may cause serious internal damage of fruit. Product quality of fruits declines by various factors while they are stored right after harvesting and among the substance in charge of post ripening action, ethylene ($C_2H_4$) biosynthesis increases fruits' respiration process after harvesting and decreases storage expectancy. Ethylene production of apples rapidly increases while storage duration becomes longer. This tendency is much clearer for the apples with vibration stress at input acceleration level. When there was no vibration stress, change in ethylene production level of apples are not very large during storage. Ethylene production rates inside the gas collecting container increased significantly ($p{\leq}0.05$) after 24 hours storage, particularly for apples with vibration stress ($0.7{\mu}l/kg{\cdot}hr$ (1st stack), $0.78{\mu}l/kg{\cdot}hr$ (2nd stack), $0.96{\mu}l/kg{\cdot}hr$ (3rd stack)); whereas less ethylene was produced in control apples ($0.18{\mu}l/kg{\cdot}hr$ during storage. Also ethylene production rates of apples according to the stack position were significantly different ($p{\leq}0.05$). The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased ethylene production.

  • https://doi.org/10.20909/kopast.2017.23.2.97 인용 PDF

Verification of Thermal Characteristics and Overturning Moment for Lateral Vibration System (수평가진 시스템의 열 특성 및 모멘트 성능 검증)

  • Eun, Hee-Kwang;Im, Jong-Min;Moon, Sang-Moo;Moon, Nam-Jin;Lee, Dong-Woo;Choi, Seok-Weon
    • Aerospace Engineering and Technology
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    • v.8 no.2
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    • pp.113-121
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    • 2009

  • Shaker system is used to simulate the vibration from the launch environment. The vibration tests are performed in the vertical and lateral direction. For the lateral vibration test, the slip table system is used with shaker system. For the latest large satellite, vibration test adaptor is made of the steel. But slip table of lateral vibration is made of magnesium, so there is big difference of thermal expansion ratio between slip table and vibration test adaptor. This paper encompasses the following items; verification process of thermal characteristics and overturning moment and a solution for lateral vibration test with steel vibration test adaptor.

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