• 한국기계가공학회지
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• 제20권1호
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• pp.125-131
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• 2021

For the vibration reliability tests, the jigs for mounting the test specimen on a vibration reliability tester are required. The dynamic stabilities of the jigs should be verified before the tests for obtaining the accurate reliability of the test specimen. This paper proposes an analytical technology for ensuring the dynamic structural stability for the test setup including the jig. The technology includes the mode analyses for checking resonance, the harmonic analyses for evaluating the dynamic structural stability of test setup including the jig, and the fatigue analyses for obtaining the durable reliability time with calculating the life cycles at the area of weakness. The cause investigation of the damaged jig during vibration reliability test of a rubber hose and the design of new revised jig are performed by using the technology. The vibration reliability test for the rubber hose with the new revised jig by analysis results is successfully conducted without any problem. Therefore the jig's design technology proposed in this paper may be useful for other items as well.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.257-261
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• 2011

The failures of local structure of marine medium-speed diesel engine occurred in durability test. The vibration response of the whole engine was in an acceptance level, but the local structures were broken. ODS test and vibration measurement were carried out in order to investigate the root cause of durability problem. These tests revealed that the root cause of failures was excessive vibration by $4.5^{th}$ resonance between engine body and local structure. The best solution to reduce the vibration response is to change the type of mount. After a rigid mount was replaced by a flexible mount, maximum vibration level dropped to 72%.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.42-47
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• 2014

In this paper, fatigue life analysis of each structure was performed through theoretical analysis method at design stage in order to verify the success or failure of the store's acoustic noise durability according to the Method 515.5 standard of MIL-STD-810F. In addition, experimental analysis was carried out through the ground and flight test by manufacturing the measuring store, and verification of the sound durability was completed through the flight test after manufacture of the actual store. Furthermore, the commercial FEM code through the PSD calculation method applying measured SPL enables verify the durability of new store components development for the future.

• 한국수소및신에너지학회논문집
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• 제19권4호
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• pp.266-275
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• 2008

The performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle has been focused so far. However, for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module and vehicle level. The test procedure to evaluate vibration and collision safety of high pressure hydrogen storage system for the fuel cell vehicle is established and its reliability is verified.

• 품질경영학회지
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• 제45권3호
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• pp.365-377
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• 2017

Purpose: In the A rotorcraft, the division of a long yaw control rod was studied to improve the heat treatment capability. The purpose of this study was to analyze whether division of yaw control rod affects quality reliability in the A rotorcraft and analyze whether it secured flight safety. Methods: The structural static test and the vibration durability test on the split shape of yaw control rod were carried out in order to examine and verify the existing structural analysis results. Results: Structural static test results showed that there were no cracks and vibration durability test results showed that there was no damage or breakage on the split yaw control rod. Conclusion: This study showed that the quality reliability was confirmed and thus the flight safety of the A rotorcraft was secured. And it is expected that the split technique of the yaw control rod will contribute to the development of the rotorcraft industry in the future.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.71-74
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• 2007

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate vibration and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.50-55
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• 2010

In recent years, the development of fuel cell vehicles has further accelerated because of environmental problem and petroleum resources shortage. The fuel cell vehicles have the stack which converts fuel to electricity. The stack is usually mounted by bush to isolate the vibration of chassis and body. This paper analyzed the vibratory characteristics of stack and chassis, body system. The wheel forces of fuel cell vehicle are measured to estimate the road load data. And the paths of vibration from wheel to stack are analyzed by CAE. According to the test and CAE results, the improvement of stack vibration are evaluated.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.4776-4783
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• 2014

1차 소음원을 저감시키기 위한 많은 연구가 진행되어 왔지만 BSR과 같은 감성품질에 대한 연구는 상대적으로 적다. 본 논문은 다축 가진기를 이용한 시트 프레임의 BSR 시험을 실시한다. 정현파 스윕(sine wave sweep) 테스트를 실시하여 BSR 소음과의 관계를 연구하고 시트 프레임의 진동 내구 시험 전후 BSR 시험을 실시한다. 그 결과 첫 번째 수평(lateral)방향 공진이 고주파의 BSR소음을 발생시키며 또한 레일의 위치에 따라 BSR 소음 특성이 변하는 것을 확인했다. 또한 시트 프레임의 내구 시험 후 시스템 강성이 감소하였고, 그에 따라 BSR 소음이 감소되는 것을 확인할 수 있었다.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.89-94
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• 2005

The compression strength of corrugated fiberboard container for packaging the agricultural products rapidly decreases because of various environmental conditions during distribution of unitized products. Among various environmental conditions, the main factors affecting the compression strength of corrugated fiberboard are absorption of moisture, long-term accumulative load, and fatigue caused by shock and vibration. An estimated rate of damage for fruit during distribution is about from 30 to 40 percent owing to the shock and vibration. This study was carried out to characterize the durability of corrugated fiberboard container for packaging the fruit and vegetables under simulated transportation environment. The vibration test system was constructed to simulate the land transportation using truck. After the package with corrugated fiberboard container was vibrated by vibration test system at various experimental conditions, the compression test for the package was performed. The compression strength of corrugated fiberboard container decreased with loading weight and vibrating time. The multiple nonlinear regression equation for predicting the decreasing rate of compression strength of corrugated fiberboard containers were developed using four independent variables such as input acceleration level, input frequency, loading weight and vibrating time. The influence of loading weight on the decreasing rate of corrugated fiberboard container was larger than other variables.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.138-142
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• 2018

본 연구에서는 플랜트 기자재 중 수충격에 매우 취약한 신축관 이음을 대상으로 수충격 발생 시 신축관 이음의 신축량의 변화를 현장에서 취득한 후 HIL 시뮬레이터의 작동데이터로 적용한 HILS 기법을 적용한 진동내구 시험을 수행하였다. 또한 진동내구 시험 시 내구수명의 주요 스트레스 인자로 신축관 내부압력을 가정하였다. 진동내구 시험은 신축관 내부 설정압 따라 진행되었으며 수명데이터를 이용, 수명데이터를 잘 따르는 곡선을 접합하여 수명예측 모델식을 유도하였고 특정 내부 설정압에서의 시험 및 수명결과를 통하여 이를 검증하였다. 한편, 시험 중 발생 된 신축관의 고장모드는 모두 벨로우즈 부 표면에 발생된 크랙과 크랙을 통한 누수 등이 있었다. 본 연구에서 유도한 수명에측 모델식은 설정압력을 스트레스 인자로 따르는 전형적인 역승모형이며 특정환경에서만 적용될 수 있는 한계를 지니고 있다. 이에 본 연구는 진동내구 수명의 가속요인인 압력 외 온도상태 등을 다양한 수명변수가 적용 가능한 복합수명예측 모델식을 개발할 예정이다.