• Title/Summary/Keyword: Durability Assessment

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A Research on Stray-Current Corrosion Mechanism of High Voltage Cable Connector on Electrification Vehicles

  • Lee, Hwi Yong;Ahn, Seung Ho;Im, Hyun Taek
    • Corrosion Science and Technology
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    • v.18 no.4
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    • pp.117-120
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    • 2019
  • Considering the tendency of development of electrification vehicles, development and verification of new evaluation technology is needed because of new technology applications. Recently, as the battery package is set outdoors of an electric vehicle, such vehicles are exposed to corrosive environments. Among major components connected to the battery package, rust prevention of high-voltage cables and connectors is considered the most important issue. For example, if corrosion of high voltage cable connectors occurs, the corrosion durability assessment of using an electric vehicle will be different from general environmental corrosion phenomena. The purpose of this study is to investigate the corrosion mechanism of high voltage cable connectors of an electric vehicle under various driving environments (road surface vibration, corrosion environment, current conduction by stray current, etc.) and develop an optimal rust prevention solution. To improve our parts test method, we have proposed a realistic test method to reproduce actual electric vehicle corrosion issues based on the principle test.

Feasibility Study the Assessment Factor of Quality Performance Index in Expressway Concrete Pavement (고속도로 콘크리트 포장에 대한 품질평가지수 평가인자의 적정성 검토)

  • Lee, Seung Woo;Kim, Gyung il;Ko, Dong Sig;Hong, Seung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.1
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    • pp.133-141
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    • 2017
  • Traffic volume increases according to highway expansion and industrial development which causes repetitive defect and durability degradation on pavement. The research of quality assurance system used abroad has introduced Korea. Korea Expressway Corporation (KEC) has developed a Quality Performance Index (QPI) that quantitatively assesses the level of quality of the final product, and practical applications. Assessment factor on concrete pavement consisted of pavement thickness, compressive strength, IRI and spacing factor. Assessment factor on concrete pavement is determined by empirical evaluation factor from abroad. In this study, analysis of evaluation factors of concrete pavement by using pavement life prediction simulation and measured data were evaluated with consideration of feasibility of the assessment factor. Pavement life, performance and durability are affected by pavement thickness, compressive strength, IRI and spacing factor in assessment factor on concrete pavement, QPI.

FINITE ELEMENT MODELING AND PARAMETER STUDY OF HALF-BEAD OF MLS CYLINDER HEAD GASKET

  • CHO S. S.;HAN B. K.;LEE J. H.;CHANG H.;KIM B. K.
    • International Journal of Automotive Technology
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    • v.7 no.1
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    • pp.109-114
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    • 2006
  • Half-beads of multi-layer-steel cylinder head gaskets take charge of sealing of lubrication oil and coolant between the cylinder head and the block. Since the head lifts off periodically due to the combustion gas pressure, both the dynamic sealing performance and the fatigue durability are essential for the gasket. A finite element model of the halfbead has been developed and verified with experimental data. The half-bead forming process was included in the model to consider the residual stress effects. The model is employed to assess the dependence of the sealing performance and the fatigue durability on the design parameters of half-bead such as the width and height of bead and the flat region length. The assessment results show that the sealing performance can be enhanced without significant deterioration of the fatigue durability in a certain range of the half-bead width. In the other cases the improvement of sealing performance is accompanied by the loss of the fatigue durability. Among three parameters, the bead width has the strongest influence.

Examining and Refining the Code for Durability Design Criteria of Concrete Carbonation (개정 콘크리트 탄산화 내구성 설계기준의 적용상 문제점 분석)

  • Lim, Nam-Gi
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.3
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    • pp.285-293
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    • 2023
  • In this research, we embarked on a meticulous analysis of the challenges inherent in real-world scenarios relating to the durability design standards of engineered concrete structures and the assessment of carbonation durability in concrete guidelines. Our investigation brought to light substantial issues concerning constructability and quality assurance. The genesis of these problems is the exclusive application of prescribed strength to exterior walls, neglecting other elements to facilitate smoother licensing procedures. While this methodology aims to mitigate financial constraints in alignment with enhanced standards, it invariably invites complications. Furthermore, it is imperative to resolve the uncertainty surrounding durability evaluations by establishing a clear and definitive objective. Alongside this, actionable steps must be formulated to forestall the emergence of fissures between the floors of residential buildings, particularly apartment complexes. It is equally essential to tackle issues connected to application by devising a comprehensive management strategy for potential cracking during the phase of maintenance.

Integrity Assessment for Reinforced Concrete Structures Using Fuzzy Decision Making (퍼지의사결정을 이용한 RC구조물의 건전성평가)

  • 손용우;정영채;김종길
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.2
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    • pp.131-140
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    • 2004
  • It really needs fuzzy decision making of integrity assessment considering about both durability and load carrying capacity for maintenance and administration, such as repairing and reinforcing. This thesis shows efficient models about reinforced concrete structure using CART-ANFIS. It compares and analyzes decision trees parts of expert system, using the theory of fuzzy, and applying damage & diagnosis at reinforced concrete structure and decision trees of integrity assessment using established artificial neural. Decided the theory of reinforcement design for recovery of durability at damaged concrete & the theory of reinforcement design for increasing load carrying capacity keep stability of damage and detection. It is more efficient maintenance and administration at reinforced concrete for using integrity assessment model of this study and can carry out predicting cost of life cycle.

Proof Load Test and Integrity Assessment of Segmental PC Box-girder Bridges (Segmental PC 박스거더교의 검증재하시험 및 건전성평가)

  • 조효남;임종권;옥승범;지광습
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.132-141
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    • 1995
  • This study is intended to propose practical but systematic and rational approaches for proof load test and integrity assessment of segmental PC box-girder bridges. The proposed models cover the whole range of field tests and assessment of such as inspections, nondestructive tests, static and dynamic load tests, structural analysis, and integrity assessment for the evaluation of load carrying capacity, serviceability, and durability of PC box-girder bridges. They are applied to a newly constructed precast segmental PC box-girder bridge which is a part of the Seoul interior circuit elevated expressway.

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Research of Reliability Assessment through the Analysis of Field Data and Taguchi Method about Vehicle Components Problem (차량부품 문제에 대한 실험계획법과 Field Data 분석을 통한 신뢰성 평가연구)

  • Kang, Chang-Hak;You, Jae-Bog;Lee, Chi-Woo;Kim, Jang-Su
    • Journal of the Korean Society of Industry Convergence
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    • v.13 no.4
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    • pp.211-217
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    • 2010
  • As the vehicle components are various, we confront unexpected problems in the development and application of them. also warranty expenses occur in the result of unconfirmed warranty.in this paper, to solve the problems of disconnection of damper Strut cable, we applied the optimum conditions through taguchi method for improvement of durability. and we made standard of reliability by weibull analysis of the field data. we acquired reliability standard by correlation with lab data and confirmed improved components satisfying the target of reliability. The analysis of reliability by field data is very useful and we need to apply this method to other components, the correlation between field data and Lab Test has influence on satisfying the target of reliability.this method would be utilized for current mass production components and upcoming developed components. the reliability of durability should be continuously used in the basis of primary technique in cope with competitive automotive companies.

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Experimental assessment for friendly-environment functional Inorganic mixed rubber asphalt Seismic waterproof strengthening method (친환경 기능성 무기질계와 고무아스팔트를 혼합한 내진방수 보강공법에 대한 실험적 평가)

  • Baek, Jong-Myeong;Hwang, Young-Ho;Shon, Jung-Chul
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1802-1808
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    • 2008
  • Recent interest in the construction sector, rising about the environment and eco-friendly recycled material resources, and increase the development of method But despite these efforts, and the diverse functional and structural changes in the structure can not be an appropriate response to the functional waterproof structural changes in the structures and appropriate response Diversification does not waterproof and functional issues such as durability, and which are occurring due to the structure to secure stability and durability, never sees the conservative economic losses due to import constructability reinforcement situation. Therefore, this study applies to structure the existing waterproof method (hereinafter referred to as structures water-resistant methode), and to review recent issues of environmental pollution and resource waste, and taking on environmental issues, such as Revelation and functional Inorganic mixed in a way to leverage the manufacturing water-resistant material "Re Inorganic, functional and environmentally friendly high-viscosity mix asphalt waterproof rubber reinforcements, and taking conservative" for the characterization and performance assessment to the issues raised by the structure and whether the judge would respond.

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Durability Characteristics and Environmental Assessment of Controlled tow-Strength Materials Using Bottom Ash (Bottom Ash를 재활용한 저강도 고유동 재료의 내구성 및 환경영향 평가)

  • 원종필;이용수;이존자
    • Journal of the Korea Concrete Institute
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    • v.14 no.2
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    • pp.223-230
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    • 2002
  • The main intent of this research was to determine the feasibility of utilizing recycling bottom ash as CLSM (controlled low-strength material). CLSM is a cementitious material, commonly a blend of portland cement, fly ash, sand, and water, that is usually flowable and self-leveling at the time of placement. The durability characteristics of mixtures made bottom ash we compared with those of fly ash CLSM in order to evaluate the effectiveness and suitability of bottom ash as material in CLSM. A comprehensive evaluation of the bottom ash in CLSM and mix proportions indicated that the bottom ash are capable of performing as CLSM mixtures. The durability characteristic of CLSM incorporating the bottom ash under various physical and chemical causes of deterioration were investigated. Test results indicated that CLSM using bottom ash has acceptable durability performance. CLSM incorporating with bottom ash were also found to be environmentally safe.

A Durability Assessment on Complex Deterioration of Concrete with Ground Granulated Blast-Furnace Slag Replacement (복합열화 환경하에서의 고로슬래그미분말 사용 콘크리트의 내구성능 평가)

  • Lee, Seung-Hoon;Kim, Hyung-Doo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.171-175
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    • 2010
  • This paper presents the experimental results of frost durability characteristics including freezing-thawing and de-icing salt scaling of the concrete for gutter of the road and marine structure. Mixtures were proportioned with the three level of water-binder ratio(W/B) and three binder compositions corresponding to Type I cement with 0%, 30% and 50% GGBS(Ground granulated blast furnace slag) replacement. Also, two different solutions of calcium chloride were used to evaluate their effect on the frost durability resistance. Specially, in case of complex of freezing and thawing with salt and carbonation, the deterioration of concrete surface is evaluated. Test results showed that the BFS30 and BFS50 mixture exhibited higher durability and lower mass loss values than those made with OPC mix and the use of GGBS can be used effectively in terms of economy and frost durability of the concrete to be in complex deterioration. Therefore, the resistance to complex deterioration with freezing-thawing was strongly influenced by the strength and the type of cement.