• Title/Summary/Keyword: Vibration Criteria

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Proposing the Thickness of 2-Way Slab Satisfying Floor Vibration Criteria for Several Boundary Condition (수직진동에 대한 사용성을 고려한 경계조건에 따른 2방향 슬래브 최소두께 제안)

  • Kim, Dong-Hyun;Lee, Min-Jung;Han, Sang-Whan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.199-202
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    • 2005
  • KCI 2003 provides minimum thickness of slab that satisfies serviceability to static displacement. Previous study (Han, et al. 2003) showed the several slabs that designed according to minimum thickness criteria had floor vibration problem. In this study, evaluate the floor vibration serviceability of KCI 2003 minimum thickness requirements for 2-way flat plate and propose the minimum thicknesses of 2-way slabs that satisfy floor vibration criteria according to several boundary condition. For this purpose, one degree of freedom model is used and Monte Carlo simulation is performed.

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A Study on the Evaluation of Ride Comfort using Human Model (인체모델을 사용한 승차감의 정량적 평가에 관한 연구)

  • Kim, Kwangsuk
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.3
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    • pp.57-64
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    • 2011
  • Vibrations on the floor in a car are transmitted to the foot, hip, and back from the seat. Human body recognizes these vibrations, but the sensitivity for each vibration is different. To evaluate these vibrations, RMS(root mean square) of accelerations, VDV(vibration does value) are commonly used. The ride comfort evaluation is usually carried out by experiments of real cars which are expensive. The purpose of this paper is to briefly review the status of several ride vibration standards and criteria having relevance to construction machinery vehicles and to suggest recommendations for the effective use of such criteria in vehicle / component development.

A Study on Blasting Vibration Control Criteria for Pre-insulated Pipe through the Numerical Analysis (수치해석을 이용한 이중보온관 발파진동 관리기준에 관한 연구)

  • Choi, Bong-Hyuck;Cho, Jin-Woo;Kim, Jin-Man;Yoo, Han-Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1471-1478
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    • 2013
  • In this paper, numerical analysis with varying distance and burial depth was performed to recommend the blasting vibration control standard for pre-insulated pipes. The blasting load model applied in the numerical analysis was verified to the comparison with the results of the field tests. It was determined from the results of the numerical analysis that the effective stress either exceeds or approaches the allowable stress of the inner steel pipe for vibration velocity greater than 4.0cm/sec while stability is obtained for vibration velocity below 4.0cm/sec. Therefore, it was determined that the blasting vibration control criteria for pre-insulated pipes must not exceed 4.0cm/sec.

Free Spanning of Offshore Pipelines by DNV

  • CHOI HAN SUK
    • Journal of Ocean Engineering and Technology
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    • v.19 no.2 s.63
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    • pp.47-52
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    • 2005
  • This paper introduces a procedure for free span and fatigue analysis of offshore pipelines per DNV-RP-F105, 2002. The new method includes the axial force and deflection load in pipelines. The screening criteria were established to calculate the allowable span lengths in the new design codes. The screening criteria allows a certain amount of vortex-induced vibration due to wave and current loading. However, the induced pipe stresses are very small and usually below the limit stresess of typical S-N curves. In contrast, the conventional criteria did not allow any vortex-induced vibration in the free span of pipelines. Thus, the screening criteria yields reduced allowable span lengths. A simplified procedure was established to calculate the fatigue damage due to long-term current distribution. The long-term current statistics was assumed with a 3-parameter Weibull distribution. The fatigue damage was estimated for the span lengths obtained from the screening criteria for various conditions. Sample calculations show the effect of axial force for various boundary conditions. Comparisons with conventional criteria are included.

A Study on the Determination of Vibration Criteria and Vibration Reduction at Projection Room Floor in a Complex Building (복합상가건물 영화관 영사실의 진동허용 규제치 결정 및 저감 대책)

  • Park, Hae-Dong;Kim, Kang-Boo;Baek, Jae-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.671-675
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    • 2002
  • 영화관의 구조설계에서 중요한 고려 인자 중에서 음향적 관점뿐만 아니라, 영사기의 진동으로 인한 영상의 떨림 현상은 관람석에서 미치는 구조물의 동적 특성 문제에 있다. 이는 영사기-스크린-관람객 사이의 3인자에 내한 상대진동허용변위에 의해 지배됨을 고려하여, 이를 만족시키는 변수 등에 따른 진동허용규재치를 결정하는 절차가 필요하다. 본 연구에서는 영화관의 진동허용규제치를 이들 3인자에 대한 변수들을 고려한 결정 과정을 공학적인 차원에서 정리하였으며, 복합상가 건물내의 영화관 영사실에 이를 만족하기 위한 진동 저감설계 자료에 활용하였다.

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Vibration Loads on KSR-III during Ground Transportation and Handling (KSR-III 로켓의 도로운송 및 핸들링에 의한 진동하중)

  • Chun, Young-Doo;Cho, Byoung-Gyu;Park, Dong-Soo;Hwang, Seung-Hyun;Kim, Jhoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.250-254
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    • 2002
  • It is conducted to analyze vibration loads on KSR-III(KSR: Korea Sounding Rocket) and its major segments during their ground transportation and various handling process. These loads may be different from the real flight environment. Inadequate assessment of these loads can cause not only local damages on the rocket system but also the critical problem like flight mission failure. Therefore, transportation and handling loads must be considered during design and attenuated to ensure that the rocket structural damage does not occur. This work is concerned with the generation of criteria and prediction of transportation and handling loads for KSR-III. The results show that the shipping container is well designed to satisfy the design requirements. The maximum vibration level recorded during whole transportation and handling for KSR-III is less than 2g, the criteria of KSR-III movement condition.

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Selection Criteria of Measurement Locations for Advanced Power Reactor 1400 Reactor Vessel Internals Comprehensive Vibration Assessment Program (APR1400 원자로내부구조물 종합진동평가 측정위치 선정 기준)

  • Ko, Do-Young;Kim, Kyu-Hyung;Kim, Sung-Hwan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.8
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    • pp.708-713
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    • 2011
  • U.S. nuclear regulatory commission(NRC) regulatory guide(RG) 1.20 requires a comprehensive vibration assessment program(CVAP) for use in verifying the structural integrity of reactor vessel internals(RVI) for flow-induced vibrations prior to commercial operation. The CVAP program consist of vibration and fatigue analysis, a vibration measurement program, an inspection program, and a correlation of their results. One of the main purposes of the analysis program is to select measurement locations, however measurement locations can not be determined by only analysis results, therefore we developed selection criteria of measurement locations for advanced power reactor 1400(APR1400) RVI CVAP, It will be used to select measurement locations and instrument types for APR1400 RVI CVAP.

A Study on the Specification of Vibration Criteria of Sensitive Equipment (고정밀장비의 진동허용규제치 사양에 관한 연구)

  • 이홍기;박해동;김두훈;김사수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.362-369
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    • 1997
  • In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be expressed in the form of 'exactness' and 'accuracy', because this is made basic data in the use of building structure design. This paper made a study on the specification of high sensitive equipment and proposed a contents of the specification.

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Perception Threshold for Horizontal Vibration of Tall Buildings (초고층 건축물의 수평진동에 대한 인지도 평가)

  • Cho, Kang-Pyo;Jeong, Seung-Hwan;Cho, Soo-Youn
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.751-756
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    • 2007
  • In this paper, perception threshold for horizontal vibration of tall buildings was investigated. After a comparative study of human comfort criteria for wind-induced vibration in foreign countries being made, perception threshold was recorded by increasing acceleration in the range of 0.2Hz through 1.2Hz of frequency in horizontal vibration experiments, and perception of subjects was examined by a proper questionnaire. Also, the results obtained from experiments of horizontal vibration were compared with Japanese standard(AIJES-A001-2004).

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Determination of the Allowable Vibration Level of the Atomic Force Microscope Equipment (원자 현미경 장비의 바닥 진동(정상 상태) 허용 기준 결정)

  • Lee, Dong-Yeon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.161-164
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    • 2000
  • Currently, Atomic Force Microscope(AFM) has been widely used to measure the surface topography of a sample by detecting interaction force between atoms on the sample and extremely sharp probe tip. The vertical resolution of AFM is mainly determined by external vibration noise. The resolution of AFM shows different values for the different environment, thus it is necessary to determine relationship between the criteria and the resolution of AFM regardless of environment. In this paper, we discuss the allowable level of floor vibration for AFM equipment at given resolution. The vibration criteria can be used as reference data to design mechanical structure and to analyze the structural dynamics of AFM equipment.

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