• 품질경영학회지
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• 제47권3호
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• pp.453-465
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• 2019

Purpose: A main purpose is to increase the operational rate and reduce operating maintenance costs by Improving the durability of Blower of Military Armored Vehicle and Self-propelled Artillery. As a result, it is expected to improve the service quality of customers. Methods: After analyzing the cause of the stop of the blower, the improvement plans were established and the effectiveness of each improvement plans were verified by testing. Results: Mechanical, electrical and environmental factors affecting brush wear were reviewed, but it was difficult to specify the cause, which necessitated a review of the application of the BLDC motor. Conclusion: After applying the BLDC motor to the blower, tests proved that the existing blower can be replaced. It is expected that this study will help improve the durability life of similar equipment that is applied with Brushed DC motors as well as blowers.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.139-144
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• 2020

Recently, the electronic equipment industry has become active due to the continuous increase in portable storage media with high-speed information communication, and in particular, the production of SSD(Solid State Drives) for miniaturization of mobile devices and high-speed information communication has increased rapidly. When the SSD is ejecting in the SSD test gender, the necessary ejecting force must be kept constant to have a lifespan applicable to the test device. When the ejecting force increased, it leads to wear of the link for ejecting, which causes a problem in that repeated durability decreases and the ejecting of the SSD becomes impossible. In this paper, the repeated durability test analysis according to the material and the reducing ejecting force design were performed to increase the life of the test gender for SSD inspection. The wear level of the pusher head and ejector was analyzed through repeated durability tests according to the material of the pusher head. The validity of the design was verified through the ejecting force test and repeated durability test of the Test gender, which was designed by carrying out the design to reduce the size and ejecting force of the test gender.

• KIEAE Journal
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• 제11권4호
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• pp.87-94
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• 2011

This study was suggested to develop sustainable durability design system and proposed the plan to evaluate design conditions that meet the intended service life and $LCCO_{2}$ reduction level of reinforced concrete structure easily from the early design stage. For that the W/B and covering depth of the concrete structure were calculated through calculation of service life based on standard specification expression and the quantitative reduction rate of the vertical member of reinforced concrete structure by the calculated W/B was applied. Life cycle of building classified into construction stage, operation stage, maintenance stage, and demolition/disposal stage and the method of $CO_{2}$ evaluation of each stage was proposed. For construction stage, the major construction materials that take up over 80% $CO_{2}$ emitting during building construction were selected and the $CO_{2}$ evaluation method for 5 standard apartment houses was proposed. Also, for operation stage, $CO_{2}$ emission was calculated through calculation of heating load by energy efficiency rating certification system. For maintenance stage, $CO_{2}$ emission was calculated using concept of re-construction by life and for demolition/disposal stage was calculated with the use of construction standard estimate. As a result of the case study by such evaluation methods, 80 years of service life and 17 specifications of sustainable durability design that meet the 40% intended $LCCO_{2}$ reduction level were deduced. The Maximum $LCCO_{2}$ reduction rate was analyzed by 47.2%.

• 한국항공우주학회지
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• 제30권5호
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• pp.127-133
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• 2002

항공기 구조 개발에 관련된 MIL-STD-1530A에는 구조 건전성을 확보하기 위한 요구사항이 기술되어 있다. 기체 구조의 내구성 및 손상허용성은 요구사항 중의 하나로서 관련 규격서의 요구조건과 절차에 따라 해석 및 시험을 통하여 입증되어야 한다. 본 논문에서는 기본 훈련기의 안전성 및 내구성 평가를 위한 실기체 내구성시험에 대하여 소개하였다. 내구성시험은 미군사규격서의 요구조건 및 절차에 따라 수행되었다. 내구성시험의 시험하중은 비행대비행 하중 스펙트럼으로 기본 훈련기의 피로하중 기준에 의거하여 개발되었다. 4배 설계수명 동안의 내구성시험을 성공적으로 완료하였으며, 기본훈련기 구조가 내구성 요구조건을 만족하고 있음을 확인하였다.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.28-34
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• 2007

In design stage of vehicles, the application of virtual durability analysis techniques enables us to cut down the necessary time and cost to carry out various physical experiments. In this study, computer simulations of vehicle suspensions were carried out with DADS program including component flexibility, and the durability analysis of vehicle components was executed with MSC/Fatigue program using the load history obtained from vehicle dynamic simulation. Driving test of a vehicle was also carried out to obtain precise input data for the durability analysis, and the results of virtual durability analysis were compared to those of experiments.

• 자동차안전학회지
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• 제12권3호
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.144-150
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• 2003

Recently, the virtual test techniques using computer simulation play an important part in the vehicle development procedures in order to reduce the development time and cost by replacing the physical prototypes of the vehicle components or systems with the virtual prototypes. In this paper, virtual durability test procedures for the vehicle suspension module have been developed. Virtual durability test consists of dynamic simulation computing load history of suspension components, fatigue analysis computing the life of components. A vehicle suspension module for dynamic simulation are developed and validated by comparison with the measured data obtained from the field vehicle test. And on the basis of the validated vehicle suspension model, fatigue analysis has been performed for the virtual durability design of the suspension components.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.523-524
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• 2009

본 연구는 최근 부각되고 있는 지속가능성능 평가를 내구성 설계에 도입하여 염해를 입은 RC구조 물의 목표 내용연수를 달성하기 위한 최적 보수 내구성 설계기법의 가능성에 대하여 살펴보고자 한다.

• 한국생산제조학회지
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• 제19권3호
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• pp.376-380
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• 2010

The capability of automotive suspension system depends on steering safety of knuckle and lower control arm. In this study, light weight is applied with lower arm by the material of aluminium alloy. Distributed stress, fatigue life and proper vibration are analyzed with multiple loads happened by automobile. The durability of lower arm can be verified by the result of structural analysis.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2159-2167
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• 2006

In order to find out a physical quantity which controls the fatigue life of a structure and to predict the fatigue life of tires, a finite element simulation methodology to use the cracking energy density (CED) and the virtual crack closure technique (VCCT) was proposed and applied to three different tires of a similar size. CED was calculated to predict the location of a crack initiation, and VCCT was used to obtain the strain energy release rate (SERR) at the tip of an initiated crack. Finite element simulations showed that SERR oscillated in the circumferential direction with its minimum occurring just before the contact zone and its maximum occurring just after the center of the contact zone, and SERR was affected significantly by the frictional force acting on the crack surface. In addition, a durability test was conducted to measure the fatigue life of the three tires. The comparison of SERR values with the test data revealed that the fatigue life increased as the amplitude of SERR decreased or as the R-ratio of SERR increased.