• Title/Summary/Keyword: human vibration

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Experiment for Seated Human Body to Vertical/Fore-and-aft/Pitch Excitation (착석자세 인체의 상하/전후/피치 가진 시험)

  • Kim, Jong-Wan;Kim, Ki-Sun;Kim, Kwang-Joon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.656-660
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    • 2009
  • Various dynamic models of seated posture human body have been developed because the importance about the ride comfort assessment of vehicles is highly emphasized from day to day. The dynamic models of human body make possible the simulation of ride comfort assessment by applied to the vehicle dynamic model. Recently, the importance of ride comfort is also regarded to working vehicles such as excavators and the research of the ride comfort assessment for working vehicle is required. Only vertical vibration dominantly occurs on the seat of the private car driving with constant velocity. In contrast, vertical/fore-and-aft/pitch vibration seriously occurs on the seat of the working excavator. So, the dynamic models of seated human body applied to working vehicles should describe the dynamic characteristics for vertical/fore-and-aft/pitch direction. In this paper, the dynamic characteristics of seated human body are represented as apparent inertia matrix. The apparent inertia matrix is obtained by the vertical/fore-and-aft/pitch excitation of seated human body. 6 resonance frequencies are observed in apparent inertia matrix. This result can be applied to develop the dynamic model for seated posture human body.

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Measurement and Analysis of Human Vibration (인체진동 측정 및 분석체계)

  • Park, Hui-Seok;Jang, Dong-Seong
    • Journal of the Ergonomics Society of Korea
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    • v.18 no.3
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    • pp.179-186
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    • 1999
  • This article aims to provide information necessary for the measurement and analysis of human vibration, especially hand-arm vibration. The major health problems associated with the use of powered hand tools are the signs and symptoms of peripheral vascular and peripheral neural disorders of the fingers and hands. To prevent these problems, it is the first and the most important to measure the amount of the vibration transmitted to the upper extremities, and analyze its characteristics against the exposure limits such as ISO standards. In our country, however, very few studies have been done on the hand-arm vibration. One of the possible reasons might be lack of knowledge for the measurement and analysis schemes. The information introduced in this article would hopefully be of help for the upcoming studies.

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Comparison and Analysis of ISO and KS Standards Related to Human Vibrations (인체진동에 대한 ISO와 KS 표준안의 비교 분석)

  • Cheung, Wan-Sup;Choi, Jae-Bon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.227-230
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    • 2000
  • This paper introduces international and Korean standards related to human-related vibration. It reviews recent standards of ISO and KS and compares them. This comparison and analysis reveals that the current direction and activity in ISO is in progress and presents logical ways of updating Korean standards in the future. Finally, the current activity of upgrading Korean standards in the Korean TC 108/SC4 is introduced.

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Comparison and Analysis of Standardised Methods for Predicting the Hazards of Whole-body Vibration and Repeated Shocks (전신 피폭 진동 및 반복 충격에 의한 위함 예측 표준 방안들의 비교 분석)

  • ;;Michael J. Griffin
    • Journal of KSNVE
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    • v.10 no.1
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    • pp.160-167
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    • 2000
  • This paper addresses issues encountered in using the ISO and national standard codes to assess the hazards of whole-body vibration and repeat shocks. Their assessment methods are given in ISO 2631-1 (1974, 1985, 1997) and BS 6841 (1987) that are now available to us. Two standard codes can yield unfortunately different assessment results even for a single measured vibration signal. Possible reasons for such different results are pointed out and, furthermore, related questions that should be re-examined in the future are raised in this paper.

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Rotational inertial double tuned mass damper for human-induced floor vibration control

  • Wang, Pengcheng;Chen, Jun;Han, Ziping
    • Structural Engineering and Mechanics
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    • v.82 no.3
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    • pp.283-294
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    • 2022
  • An inerter is a passive mechanical element whose inertance can be thousands of times its own physical mass. This paper discusses the application of an inerter-based passive control system, termed rotational inertial double-tuned mass damper (RIDTMD), to mitigate human-induced floor vibrations. First, the acceleration frequency response function of the floor with an RIDTMD is first derived. It is then employed to determine the optimal design parameters of the RIDTMD using the extended fixed-points technique. Based on a theoretical analysis, design-oriented empirical functions are proposed for the RIDTMD optimal parameters, whose performance for floor vibration control is evaluated by numerical examples, in which three typical human-induced load types are considered: walking, jumping, and bouncing. The results indicate that the applicability and effectiveness of the RIDTMD for human-induced floor vibration control are robust for various load types, load frequencies, and floor natural frequencies. For the same mass ratio, the RIDTMD is better than the TMD in reducing the floor vibration amplitude and improving the effective frequency suppression bandwidth, and for the same vibration suppression effect, the mass of the RIDTMD is much lighter than that of the TMD.

Development of a Test Dummy for the Evaluation of Driver's Response to Vehicle Vibration (운전 자세에서의 인체진동 평가용 시험용 더미 개발)

  • 장한기;홍석인;송치문;김기선;이정훈;김광준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.105-108
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    • 2004
  • This paper introduces a process of the development of a vibration test dummy for the posture of inclined seating. Experimental devices was invented to measure apparent mass curves on the contact point of the hip and the back of a seated human body. During the excitation of a rigid seat secured to a hydraulic exciter, force and acceleration signals were measured on the contact points to determine the apparent mass. In order to describe nonlinear characteristics of a human body, seven levels of Gaussian random signal were used for the base excitation. The modeling of the human body will be performed using measured apparent mass curves. The modeling will be done by June and the prototype of the test dummy will be invented in the following six months.

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A Study on Comparison between the Vibration Characteristics of the King Songdok Bell and the Human Body (인체와 성덕대왕 신종의 진동 특성 비교 연구)

  • Jeon, Jong-Won;Chin, Yong-Ohk
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.10
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    • pp.3119-3127
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    • 2000
  • This paper is a study to find a new method of feature selection for vibrationof buman body by analyzing correlationof vibration between King Songdok Bell and Human body. The vibration characteristics are analyzed by matching body, vocal tract, diaphragm and asymmetrical clements of human body with Bell, resonator, hole in the ground and asymmetical elements. In the result, the characteristics of sound vibrationof King Songdok Bell is useful to apply it to vibration characteristics of human body because the vibration characteristics of ech elements is alike.

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A spectral model for human bouncing loads

  • Jiecheng Xiong;Jun Chen
    • Structural Engineering and Mechanics
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    • v.86 no.2
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    • pp.237-247
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    • 2023
  • Fourier series-based models in the time domain are frequently established to represent individual bouncing loads, which neglects the stochastic property of human bouncing activity. A power spectral density (PSD) model in the frequency domain for individual bouncing loads is developed herein. An experiment was conducted on individual bouncing loads, resulting in 957 records linked to form long samples to achieve a fine frequency resolution. The Welch method was applied to the linked samples to obtain the experimental PSD, which was normalized by the bouncing frequency and the harmonic order. The energy, energy distribution center, and energy distribution shape of the experimental PSD were investigated to establish the PSD model. The proposed model was used to analyze structural vibration responses using stochastic vibration theory, which was verified via field measurements. It is believed that this framework can evaluate the vibration capacity of structures excited by bouncing crowds, such as concert halls and grandstands.

Characteristics of Transmission of Floor Vibration and Floor Impact Noise Due to Human Activities (거주자의 거동으로 발생하는 바닥진동의 층간 전달 및 바닥충격음의 음압레벨 특성 평가)

  • Lee, MinJung;Choi, HyunKi
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.27 no.1
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    • pp.5-13
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    • 2017
  • Noise complaints among neighbors in apartment building are mainly caused by floor impact noise that is structure born noise due to occupant induced floor vibration. To control this noise problems many researchers have investigated floor systems and finishing materials. Light-weight impact noise affects by finishing materials, but heavy-weight impact noise induced by heel impacts during normal walking or jumping of children is concerned with structural system and floor vibration. To figure out the characteristics of floor impact noise and transmission of floor vibration due to human activities, vibration tests were conducted in apartment buildings. Impact hammer, heel drop and walking activities were loaded at center of upstairs living room, and accelerations of slabs for both upstairs and downstairs and sound pressure levels for downstairs were measured. The acceleration ratio of transmitted floor vibration to downstairs and human induced vibration in upstairs was between 0.5 and 1.0 according to slab size, wall, and load type. And floor impact noise occurred in the range of natural frequency of slab.

VSimulators: A New UK-based Immersive Experimental Facility for Studying Occupant Response to Wind-induced Motion of Tall Buildings

  • Antony Darby;James Brownjohn;Erfan Shahabpoor;Kaveh Heshmati
    • International Journal of High-Rise Buildings
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    • v.11 no.4
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    • pp.347-362
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    • 2022
  • Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.