• 제목/요약/키워드: Strength Evaluation

검색결과 4,821건 처리시간 0.036초

아스팔트 수송용 철도차량 탱크의 구조강도 평가 (Structural Strength Evaluation for Tank of Tank Car used for Carrying Asphalt)

  • 임충환;구병춘
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1024-1030
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    • 2007
  • We studied on the characteristics of many kinds of tank cars carrying hazard materials and performed structural strength evaluation for tank of asphalt tank car using finite element analysis. We analyzed the tank strength according to JIS E 7102(Design Method for Tanks of Tank Cars). It was found that the maximum stress obtained at the area supported by the saddle is much lower than the yield stress and the criteria of JIS E 7102.

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접착 면 처리 방법에 따른 이종 압축강도 콘크리트의 접착성능 평가에 관한 실험적 연구 (An Experimental study on bonding performance evaluation of Bi-compressive strength concrete according to surface preparation)

  • 김민성;임희섭;이한승;양원기
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.282-283
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    • 2014
  • An active study on UHPC, which has been recently used in high-rise building and bridges, is in progress. However, research on adhesion strength of normal concrete and UHPC is required to be studied due to the lack of information. In this study, experimental research progress for adhesion strength (shear strength of adhesive surface) evaluation of Bi-compressive strength concretes (UHPC, Normal concrete) is proceeded. First, specimens using glue are produced and surface treatment methods of concrete bonded section are considered. Second, Direct Shear test is applied on concrete bonded section of UHPC (80~180MPa) and Normal Concrete (NC). As a result of this study, it is confirmed that bond strength is deteriorated as the difference of intensity ration of NC and UHPC increases.

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A New Form of Nondestructive Strength-Estimating Statistical Models Accounting for Uncertainty of Model and Aging Effect of Concrete

  • Hong, Kee-Jeung;Kim, Jee-Sang
    • 비파괴검사학회지
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    • 제29권3호
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    • pp.230-234
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    • 2009
  • As concrete ages, the surrounding environment is expected to have growing influences on the concrete. As all the impacts of the environment cannot be considered in the strength-estimating model of a nondestructive concrete test, the increase in concrete age leads to growing uncertainty in the strength-estimating model. Therefore, the variation of the model error increases. It is necessary to include those impacts in the probability model of concrete strength attained from the nondestructive tests so as to build a more accurate reliability model for structural performance evaluation. This paper reviews and categorizes the existing strength-estimating statistical models of nondestructive concrete test, and suggests a new form of the strength-estimating statistical models to properly reflect the model uncertainty due to aging of the concrete. This new form of the statistical models will lay foundation for more accurate structural performance evaluation.

경량 재료의 T형 접합이음의 피로강도 평가 (Fatigue Strength Evaluation of T-Peel Adhesive Joing for Light Weight Material)

  • 이강용;공병석;최홍섭
    • 한국자동차공학회논문집
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    • 제6권6호
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    • pp.166-173
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    • 1998
  • The evaluation of joint fatigue strength of light weight materials for an electrical vehicle body has been performed through T-peel joint tests with the design parameters such as joint style, adherend type, adherend thickness, adhesive thickness, and various adhesives. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the zero stress ratio. It was observed that the fatigue strength of the joint increases with the increase of the adherend thickness. With the increase of the adhesive thickness, however, the fatigue strength of the joint increases insignificantly. An aluminum-FRP adherend combination shows much higher fatigue strength than an aluminum-aluminum adherend combination. The results of fatigue tests were found to be consistent with those of static tests.

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AC / PCC 복합포장 경계면 재료의 부착 성능 평가 (Evaluation of Bond Performance for AC overlay on PCC Pavement)

  • 김동규;황현식;;류성우;조윤호
    • 한국도로학회논문집
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    • 제18권5호
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    • pp.1-9
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    • 2016
  • PURPOSES : This study focuses on the evaluation of interface performance with varying surface texture and tack coat application in an asphalt overlay. METHODS : The evaluation is carried out in two phases: tracking test and interface bond strength test. Using an image processing tool, tracking test is conducted to evaluate the susceptibility of the tack coat material to produce excessive tracking during application. Using the pull-off test method, the bond strength test is performed to determine the ability of the interface layer to resist failure. RESULTS : Results show that the underseal application yields less tracking compared to other applications. However, the bond strength is barely within the minimum acceptable value. On the other hand, RSC-4 produces higher bond strength for all surface types, but the drying time is long, which produces excessive tracking. CONCLUSIONS : While underseal application may be suitable for a trackless condition, the bond strength is less appealing compared to the rest of the tack applications available. RSC-4 demonstrated a high and consistent bond strength performance, but more time is required for drying to avoid excessive tracking. Tack coat application and surface type combination produce varying results. Therefore, these should be considered when selecting suitable future tack coat application options.

Spot 용접이음재의 피로수명 예측에 관한 확률적 검토(II) : 피로강도 평가법의 신뢰성 검증 (Statistical Investigateion of Fatigue Life Predictioin of the Spot Welded Lap Joint(II) ; to verity reliabilty of fatigue strength estimatioin method)

  • 손일선;배동호
    • 한국자동차공학회논문집
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    • 제7권7호
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    • pp.242-249
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    • 1999
  • Spot welding is very important and useful technology in fabrication of an automobile body structure. Because fatigue strength of the spot welding point is however considerably lower than parent metal due to stress concentration at the nugget edge, accurate stress analysis and fatigue stength evaluation of spot welded lap joint are very important to valuate the reliability and durability of automobile body structure and to establish a criterion of long life fatigue design. Many invetigators have studied so far onsystematic fatigue strength evaluation with various methods. It is however necessary to verify their reliability and abailability for practical application to fatigue design of spot welded structure, Thus,in this study, fatigue strength evaluation methods of spot welded lap joint. which are the maximum principal stress method. the fracture and availability with the Weibull probability distribution. From the results, it was found that reliability and availability withe the Weibull probaility distribution. From the results, it was found that reliability and availability of the suggest fatigue strength estimation methods methods were higher than $\Delta$P-$N_f$ relation. However, among them , reliability of the maximum pricipal stress method was the highest.

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Damage simulator를 이용한 선박의 손상강도에 관한 연구 (A Study of Strength of Damaged Ship Structures Using Damage Simulator)

  • 한대석;조대승;김진형;이탁기;임채환;이제명
    • 대한조선학회논문집
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    • 제44권4호
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    • pp.439-444
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    • 2007
  • A damage analysis simulator, which is applicable for evaluating the residual strength of damaged ship, was developed in this paper. For this process, CDM (Continuum Damage Mechanics) approach has been implemented to the simulator by virtue of the numerical technique for evaluation of crack initiation and/or enlargement. A damage calculation program has been linked with a commercial finite element analysis code (NASTRAN) and a ultimate strength evaluation program (LSAP) in order to assess residual strength of damaged ship. As a results of series calculation for the frigate model, giving the quantitative structural damage to the ultimate strength evaluation, a residual strength with damage is predicted to be at least 70 percentage lower than the case of intact condition. It was found that the proposed technique can be used as a design support tool in the field of simulation based ship design.

초음파 시험에 의한 콘크리트의 조기 강도 판정에 관한 연구 (The Study on Earlier Evaluation of Concrete Strength Using Ultra Sonic Velosity Method)

  • 김화중;이도헌;윤상천;박정민;최신호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.136-141
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    • 1995
  • The early evaluation on strength of concrete is useful to achieve on quality control and improvement of properties of concrete. Especially, we could say that the confidence of construction is increased by the increase durability and safety building, due to early evaluation. In this study, was proposed to ultra-sonic pulse method as a early evaluation method for strength of concrete with main parameter, sush as W/C ratio and S/A ratio. The experiment results are summarized to follow as : $\circled1$ The ultra-sonic pulse was decreased as the increase of W/C ratio. $\circled2$ The maximum value for the ultra-sonic pulse velocity and compressive strength was presented in the case of 40% S/A ratio and these value was decreased as the change of S/A ratio over 40% $\circled1$ The relationship of the ultra-sonic pulse velocity and compressive strength on 28days according to the change of W/C and S/A ratio is to be: $F_{28} = -209193R^2 + 384417R - 1763441$(W/C Ratio) $F_{28} = 1726R^2 - 774R - 502 (S/A Ratio)

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선체의 부식쇠모강판의 대기중 및 해수중 피로강도평가에 관한 연구 (Fatigue Strength Evaluation of Rusting Decayed Hull Steel Plate in Air and in Artificial Seawater Condition)

  • 김원범;백점기;암전광정;시도호
    • 대한조선학회논문집
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    • 제43권4호
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    • pp.467-475
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    • 2006
  • Fatigue strength of hull structural steel plate, extracted from longitudinal bulkhead of a 17-year-old ore/oil carrier for renewal, was investigated in air and in artificial seawater condition. The surface of the plate was covered with corrosion pits and they proved to be crack initiation sites by fractography using SEM. From this research, it was found that the evaluation method for fatigue strength of virgin mild steel plates in air and in artificial seawater can also be applied to the evaluation of the fatigue strength of mild steel plates those were long-term exposed to a corrosive environment and their surfaces had been rusted intensively.

설계사례를 이용한 전면 벽체/보강재의 연결강도 평가방법에 관한 비교 연구 (A Comparative Study on Connection Strength Evaluation Methods of Wall Facing-Geosynthetics using the Design Case)

  • 한중근;홍기권;신주옥;조삼덕;이광우
    • 한국지반신소재학회논문집
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    • 제8권2호
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    • pp.21-29
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    • 2009
  • 블록식 보강토옹벽의 설계 시 국부적 안정성 평가에 있어서 실험적 방법을 통한 전면블록과 보강재 사이의 연결강도에 대한 특성을 평가해야 한다. 그러나 NCMA 및 FHWA에서 제안하고 있는 연결강도 평가방법을 적용할 경우에는 다소 보수적인 평가결과 나타나게 된다. 따라서 본 연구에서는 전면블록과 지오그리드 보강재 사이의 연결강도 시험을 수행하였다. 또한 시험결과를 NCMA, FHWA 및 Soong & Koerner가 제안한 평가방법에 의해 블록식 보강토옹벽 설계사례에 적용하였다. 그 결과, Soong & Koerner에 의해 제안된 연결강도 시험으로부터 얻어진 극한연결강도를 허용연결강도로서 적용하여도 설계시 요구되는 안정성을 만족하는 것으로 나타났다.

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