• Title/Summary/Keyword: Durability testing

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Durability Prediction of Door W/H System Using FEM Analysis (전면 도어 와이어하니스 시스템의 내구 수명 예측에 관한 연구)

  • Kim, Byeong Sam;Lim, Kwangkyu
    • Journal of Auto-vehicle Safety Association
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    • v.5 no.2
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    • pp.51-56
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    • 2013
  • In vehicle's door wiring harness (W/H) system is more toward to arrange a passenger compartment than a hinge and a weatherstrip. An opening/closing member of a vehicle is attached to a vehicle by a hinge in a manner enabling easy opening and closing of the opening/closing member. Such members include doors, such as side-doors and rear doors, and other opening/closing members, such as trunk lids. This article gives some insight into the dimensioning process, with special focus on large deflection analysis of wiring harness(W/H) in vehicle's door structures for durability problem. The Finite elements analysis for door wiring harness(W/H) is used for residual stresses and dimensional stability with bending flexible. Durability test data for slam test specimens were compared with the numerical predicted fatigue life for verification. The final testing of the component combines the effects of these microstructural features with the complex stress state arising from the combined service loading and residual stresses.

Investigation of Physical and Mechanical Properties for a Central Core Rockfill Dam (중심코아형 록필댐 제체의 물리적 및 역학적 특성 조사)

  • 신동훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.345-350
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    • 1999
  • In this study the results of investigation on the physical and mechanical properties of a rockfill dam body were provided. On the crest of the old Namgang dam to be excavated partially, various in-situ tests(boring with SPT, sampling of undisturbed sample, field density test, field permeability test) and geophysical investigation works were performed Rock materials, i.e., shale and sandstone, were collected, and their slake durability was evaluated using slaking durability testing method which is suggested by ISRM.

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Reliability Evaluation of Air Spring for Railway Vehicle (철도차량용 공기스프링 신뢰성 평가기준 및 시험)

  • Woo Chang-Su;Kim Wan-Doo;Kim Suk-Won;Kim Young-Gu
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.597-603
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    • 2003
  • Air spring system in railway vehicles primarily ensure the air suspension of the vehicle body. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestic development productions are obtained the good results.

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Durability and Retention of Performance in Hydraulic Fluid

  • Tam Nelson
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2005.10a
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    • pp.53-66
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    • 2005
  • [ $\cdot$ ] Performance can be evaluated beyond specification and requirements using existing pump tests $\cdot$ Bench testing of stressed fluids can deonstrate Retention of Performance

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Study on Accelerated Life Test Design for a Gear Type Lubrication Pump for Automatic Transmission (자동변속기 윤활용 기어펌프의 가속 수명시험 설계에 관한 연구)

  • Park, Jong-Won;Jung, Dong-Soo
    • Journal of Applied Reliability
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    • v.12 no.3
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    • pp.201-213
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    • 2012
  • A gear type lubrication pump is an essential component of the powertrain and has a major role for supplying oil to the gears and bearings in automatic transmission with a hydraulic clutch. Therefore, the durability test code design of lubrication pump is very important to ensure the reliability of the entire transmission and the vehicle. In this study, the design process for the life testing of lubrication pump has been generalized by four steps. The four design steps of the life testing of lubrication pump consist of the configuration of load spectrum, rain flow counting and analysis of load level, the equivalent damage assessment and test code generation. In fact, the load spectrum should be obtained from the field operating condition but that kind of data is the top secret of manufacturers. This is not open to the public in general. So we could use the artificially simulated load spectrum instead of field obtained one and focused on the development of the general process for designing the life test of a gear type lubrication pump. Reliability goals for lubrication pump, pressure, torque, temperature and load spectrum, if present, as appropriate for the given test conditions, accelerated life testing for the lubrication pump can be designed by the developed design steps.

Flexible Durability and Characteristics of ZnO, AZO and ITO Thin Films Grown by Aerosol Deposition Process (에어로졸 증착 공정으로 제조된 ZnO, AZO, ITO 박막의 특성과 유연 내구성)

  • Lee, Dong-Won;Cho, Myung-Yeon;Lee, Sang-Hun;Kim, Yong-Nam;Lee, Daeseok;Koo, Sang-Mo;Oh, Jong-Min
    • Journal of IKEEE
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    • v.21 no.4
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    • pp.404-407
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    • 2017
  • We investigated the microstructure, electrical and optical characteristics of ZnO, AZO and ITO films using aerosol deposition process. As gas consumption increased, the electrical and optical characteristics of ZnO, AZO and ITO films were improved, and electrical and optical characteristics of ZnO, AZO and ITO films with a thickness of 400 nm were successfully fabricated on PET substrates at room temperature. The mechanical flexibility durability test shows that the ZnO films can withstand 5,000 cycles and AZO and ITO films occurs to crack in films with degradation of resistance and transmittance. Even though the AZO and ITO films shows slightly lower durability than the ZnO films, this is expected to improve performance of films through optimized processing condition and particle size control.

Effect of various MEA fabrication methods on the PEMFC durability testing at high and low humidity conditions (MEA 제조 방법에 따른 상대습도 변화가 PEMFC 내구성에 미치는 영향)

  • Kim, Kun-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.86.2-86.2
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    • 2010
  • In order to improve polymer electrolyte membrane fuel cell (PEMFC) durability, the durability of membrane electrode assemblies (MEA), in which the electrochemical reactions actually occur, is one of the vital issues. Many articles have dealt with catalyst layer degradation of the durability-related factors on MEAs in relation to loss of catalyst surface area caused by agglomeration, dissolution, migration, formation of metal complexes and oxides, and/or instability of the carbon support. Degradation of catalyst layer during long-term operation includes cracking or delamination of the layer which result either from change in the catalyst microstructure or loss of electronic or ionic contact with the active surface, can result in apparent activity loss in the catalyst layer. Membrane degradation of the durability-related factors on MEAs can be caused by mechanical or thermal stress resulting in formation of pinholes and tears and/or by chemical attack of hydrogen peroxide radicals formed during the electrochemical reactions. All of these effects, the mechanical damage of membrane and degradation of catalyst layers are more facilitated by uneven stress or improper MEA fabrication process. In order to improve the PEMFC durability, therefore, it is most important to minimize the uneven stress or improper MEA fabrication process in the course of the fabrication of MEA. We analyzed the effects of the MEA fabrication condition on the PEMFC durability with MEA produced using CCM (catalyst coated membrane) method. This paper also investigated the effects of MEA fabrication condition on the PEMFC durability by adding additional treatment process, hot pressing and pressing, on the MEA produced using CCM method.

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Durability and Performance Requirements in Canadian Cement and Concrete Standards (캐나다 시멘트 및 콘크리트의 내구성 및 제성능에 대한 규준)

  • Hooton, R.D.
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.5-21
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    • 2006
  • Traditional standards and specifications for concrete have largely been prescriptive, (or prescription-based), and can sometimes hinder innovation and in particular the use of more environmentally friendly concretes by requiring minimum cement contents and SCM replacement levels. In December 2004, the Canadian CSA A23.1-04 standard was issued which made provisions (a) for high-volume SCM concretes, (b) added new performance requirements for concrete, and (c) clearly outlined the requirements and responsibilities for use in performance-based concrete specifications. Also, in December 2003, the CSA A3000 Hydraulic Cement standard was revised. It (a) reclassified the types of cements based on performance requirements, with both Portland and blended cements meeting the same physical requirements, (b) allows the use of performance testing for assessing sulphate resistance of cementitious materials combinations, (c) includes an Annex D, which allows performance testing of new or non-traditional supplementary cementing materials. From a review of international concrete standards, it was found that one of the main concerns with performance specifications has been the lack of tests, or lack of confidence in existing tests, for judging all relevant performance concerns. Of currently used or available test methods for both fresh, hardened physical, and durability properties, it was found that although there may be no ideal testing solutions, there are a number of practical and useful tests available. Some of these were adopted in CSA A23.1-04, and it is likely that new performance tests will be added in future revisions. Other concerns with performance standards are the different perspectives on the point of testing for performance. Some concrete suppliers may prefer processes for both pre-qualifying the plant, and specific mixtures, followed only with testing only 'end-of-chute' fresh properties on-site. However, owners want to know the in-place performance of the concrete, especially with high-volume SCM concretes where placing and curing are important. Also, the contractor must be aware of, and share the responsibility for handling, constructability, curing, and scheduling issues that influence the in-place concrete properties.

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Studies on the Thin Rubber Coated Fabrics. (Part 2) Physical Properties of the Coated Fabric with Rubber Compounds Having Different Viscosity (박막(薄膜) Rubber Coated Fabrics에 관(關)한 연구(硏究)(제2보(第2報)) Viscosity가 다른 배합(配合)고무를 각종(各種) 원반(原反)에 도포(塗布)했을때의 물리적(物理的) 성능(性能)에 대(對)하여)

  • Kim, Joon-Soo;Lee, Myung-Whan;Yum, Hong-Chan;Lee, Sook-Ja;Rhim, Kwang-Kew
    • Elastomers and Composites
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    • v.1 no.1
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    • pp.49-55
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    • 1966
  • Based upon the results of the previous work, the experiments are concentrated on the improvement of the durability of rubber coated fabrics as a rain garment material. To obtain a much lighter and durable coated fabric, several kinds of light weight cotton prints having almost equal density in warp and fillingwise were chosen. Rubber coating on these prints was made by topping and spreading process using rubber compound of various viscosity, and the physical properties of final product were analysed and interpreted in terms of adhesion and durability. The results are as follows. 1. Any noticeable difference between two coating processes was not found in terms of physical properties. 2. Base fabrics should be dipped once into a dilute rubber compound before coating operation in order to obtain a uniform adhesion and physical properties, and the optimum range of the viscosity of dipping paste are from 100 poise to 200 poise. 3. Generally, the tearing strength of the coated fabrics is inversely proportional to the adhesion. 4. It was assumed that the increase of the water proofness after water immersion on the finished material which have dense base fabric is chiefly due to the swelling of the cellulosic fiber.

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Accelerated Test Program for Durability Characteristics of GFRP Rebars (내구특성 파악을 위한 GFRP 보강근의 촉진실험 연구)

  • Kim, Hyeong-Yeol;You, Young-Jun;Park, Young-Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.157-164
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    • 2006
  • This paper presents the durability characteristics of commercially available CFRP rebars under various environmental conditions. Two types of GFRP rebars were tested by using an accelerated aging method. A total of 264 rebar specimens were conditioned up to 132 days in the moisture, chloride. alkaline, and freeze-thaw environmental conditions. The durability characteristics of conditioned rebars were obtained by comparing the tensile strength, horizontal shear strength, and elastic modulus between the unconditioned and conditioned GFRP rebars. The test results indicated that the mechanical properties of GFRP were significantly reduced after conditioning. Long-term degradation of GFRP rebars was also estimated using the results of a short-term durability test.