Physiological Responses and Subjective Discomfort of Simulated Whole-Body Vibration from a Mobile Underground Mining Machine

1988 ◽  
Vol 32 (11) ◽  
pp. 719-723 ◽  
Author(s):  
Thomas G. Bobick ◽  
Richard L. Unger ◽  
Sean Gallagher ◽  
Diane M. Doyle-Coombs
Keyword(s):  
Underground Mining ◽  
Whole Body Vibration ◽  
Vertical Vibration ◽  
Whole Body ◽  
Mining Machine ◽  
Body Vibration ◽  
Vibration Data ◽  
Computer Controlled ◽  
Selected Effects ◽  
Subjective Discomfort

The U.S. Bureau of Mines has developed an in-house facility to evaluate selected effects of whole-body vibration (WBV) levels experienced by underground mobile equipment operators. Vertical vibration data were collected from a coal haulage vehicle via a uniaxial accelerometer attached to the machine frame under the operator's seat. Data were analyzed and processed so a computer-controlled platform could approximate the vibration signals. Eight men (35.5 yr ± 6.5 SD) participated in a pilot study to evaluate the effects of shock and WBV on heart rate (HR), blood pressure (BP), and subjective discomfort. Subjects were exposed to vibration for 30-min periods while seated in a typical seat (backrest angle at 90° or 130°) that was plain steel or modified with 2 in foam padding. Subjects repeated the same protocol on a separate day, without the vibration. Results indicated the vibration significantly increased the HR (p < 0.01), systolic BP, mean BP, the number of times subjects reported discomfort, and overall subjective discomfort rating (p < 0.05). When seated in the steel seat, the overall discomfort rating (p < 0.001) and the number of times discomfort was reported (p < 0.05) increased significantly. Seatback angle had no significant effect on any of the dependent measures.

scholarly journals Evaluation of Human Discomfort from Combined Noise and Whole-Body Vibration in Passenger Vehicle

2019 ◽  
Vol 16 (2) ◽  
pp. 6808-6824
Author(s):  
M. F. Aladdin ◽  
N. A. A. Jalil ◽  
N. Y. Guan ◽  
K. A. M. Rezali ◽  
S. A. Adam
Keyword(s):  
Noise Exposure ◽  
Whole Body Vibration ◽  
Transportation Systems ◽  
Vertical Vibration ◽  
Comfort Level ◽  
Whole Body ◽  
Vehicle Speed ◽  
Noise And Vibration ◽  
Body Vibration ◽  
Vibration Data

Exposure to noise and whole-body vibration (WBV) has been a key element in determining comfort levels in transportation systems. In the automotive industry, researchers and engineers continuously work on reducing noise and vibration levels to minimize discomfort. Noise annoyance in vehicles results from structure-borne as well as air-borne noise from vehicle powertrain, tires and aeroacoustics. Whole-body vibration affects vehicle passenger comfort at the seat pan, back rest and feet. The objective of this research is to evaluate the comfort level of seated passengers in a vehicle from noise and whole-body vibration by considering both separate and combined modality. The noise and vibration data were recorded and analysed in two vehicles on the same highway road with four different speeds. The vibration exposure in vehicle were evaluated based on ISO2631-1:1997. Noise exposure was based on A-weighted sound pressure level. The combined discomfort on noise and vibration were quantified. The vibration results identified clear dominant of z-axis vertical vibration on seat pan, backrest and feet in both vehicles. The discomfort of combined noise and vibration showed that vehicle B caused a higher discomfort level at the high vehicle speed of 90 km/h and 110 km/h. The Relative Discomfort Indicator (RDI) were introduced to compare levels of discomfort from noise and vibration in different vehicles with varying speeds. The result suggests that the RDI value for vehicle A relative to vehicle B is negative at higher vehicle speed which further indicates that at higher speed, vehicle B have a higher discomfort level compared to vehicle A. The RDI value is expected to be useful for automotive Noise, vibration and harshness (NVH) improvement.

Influence of Whole-Body Vertical Vibration on Vision Performance

1996 ◽  
Vol 15 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Barbara Harazin ◽  
Ladislav Louda ◽  
Krystyna Pawlas ◽  
Zdenek Jandak
Keyword(s):  
Visual Acuity ◽  
Whole Body Vibration ◽  
Mean Amplitude ◽  
Vertical Vibration ◽  
Whole Body ◽  
Sinusoidal Vibration ◽  
Body Vibration ◽  
Black And White ◽  
Clear Vision ◽  
Iso 2631

A new method of studying effects of whole-body vibration on visual acuity was developed. Nine seated subjects were exposed to vertical (z-axis) sinusoidal vibration with mean amplitude in the range of 0.9 to 11.2 ms−-2 r.m.s. Frequency responses of vibration levels resulting in equal 10% decrease of the visual acuity were determined for each subject over the frequency of 6.3 Hz to 63 Hz. The visual acuity was ascertained by the maximum distance of clear vision of black and white square field contours having a 1 mm side and arranged in a chessboard with total area of 1 cm x 1 cm. In comparison with the vertical weighting curve recommended by the Standard ISO 2631-1985, the slightly different mean contour of whole-body vibration required to produce the same decrement in visual acuity was found to be below 12.5 Hz and above 31.5 Hz.

scholarly journals Frequency Masking Effects for Vertical Whole-Body Vibration for Seated Subjects

Vibration ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 357-370
Author(s):  
Anna Schwendicke ◽  
M. Ercan Altinsoy
Keyword(s):  
Narrow Band ◽  
Whole Body Vibration ◽  
Wide Frequency Range ◽  
Vertical Vibration ◽  
Whole Body ◽  
Perception Threshold ◽  
Body Vibration ◽  
Narrow Band Noise ◽  
Band Noise ◽  
Close Proximity

Masking occurs when the perception of a stimulus is affected or covered by the presence of another signal in close proximity either in time or frequency. This study investigated frequency masking effects across a wide frequency range for whole-body vibration (WBV). The hypothesis that masking effects for WBV might be caused by sub-channels within the Pacinian channel was explored in two experiments. One experiment explored the masking effects of narrow band noise (NBN) on the perception threshold of sinusoidal vibrations; another explored the effect of different widths of NBN on the shift of the perception threshold for vertical vibration of seated subjects. The results show distinct masking effects for WBV based on frequency, albeit they do not support the existence of sub-channels within the Pacinian channel. Neither the typical masking effects associated with critical bands nor threshold shifts dependent on the bandwidth of the narrow band noise can be shown. Thus, the hypothesis does not appear to hold for WBV, but frequency masking must be considered for future studies and tactile applications.

Effect of gender on the biodynamic responses to vibration induced by a whole-body vibration training machine

2019 ◽  
Vol 233 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Naser Nawayseh ◽  
Hawra Al Sinan ◽  
Shamma Alteneiji ◽  
Sadeque Hamdan
Keyword(s):  
Whole Body Vibration ◽  
Vertical Vibration ◽  
Whole Body ◽  
Vertical Acceleration ◽  
Apparent Mass ◽  
Body Vibration ◽  
Vibration Training ◽  
Training Programmes ◽  
Whole Body Vibration Training ◽  
Vibrating Plate

Whole-body vibration training machines are used by both male and female users. However, studies investigating the biodynamic responses to vibration during training have used either mixed-gender subjects or male subjects. No study has investigated the effect of gender on the biodynamic responses under vibration training conditions. The objective of this study is to investigate the effect of gender on the apparent mass and the vibration of the head of standing people during exposure to vibration. A total of 40 subjects (20 females and 20 males) were exposed to vertical vibration at six frequencies in the range 20–45 Hz and vibration acceleration in the range 10.8–20.9 m/s2 (peak). The subjects stood on a force platform mounted on the vibrating plate of the machine adopting an upright standing posture with their knees unlocked and their arms straight along their bodies. The vertical acceleration and force at the interface between the vibrating plate and the feet were measured and used to calculate the apparent mass. The accelerations of the head in the x-, y- and z-directions were also measured and used to calculate the transmissibility to the head. The apparent mass of males was found higher than that of females. The transmissibility to the head in all directions was found higher in females than males. The differences in the biodynamic responses between males and females were attributed to the differences in body properties and structure of the two genders. The results of this study imply the need for gender-specific vibration training programmes.

International Roughness Index Thresholds Based on Whole-Body Vibration in Passenger Cars

2020 ◽  
pp. 036119812096047
Author(s):  
Peter Múčka
Keyword(s):  
Whole Body Vibration ◽  
Vertical Vibration ◽  
Whole Body ◽  
Vehicle Speed ◽  
Passenger Cars ◽  
International Roughness Index ◽  
Body Vibration ◽  
Car Seat ◽  
Roughness Index ◽  
Iso 2631

This study analyzed whole-body vibration (WBV) on a car seat (seat surface and feet) in passenger cars as a function of longitudinal road roughness. Measurements were provided on nine different cars in six categories and included a total travel distance of 1,860 km. The root mean square (RMS) of the frequency-weighted acceleration was used to quantify WBV. The relationship between seat acceleration response and comfort reactions according to the ISO 2631-1 and the International Roughness Index (IRI) was estimated. IRI thresholds were proposed as a function of vehicle speed and road category. Proposed IRI thresholds decreased with vehicle velocity and were similar with published IRI threshold proposals based on simulation. IRI thresholds as a function of speed limit should decrease with power by approximately –0.75. Substantially lower (by ~ 40%) IRI thresholds were calculated for the total vibration value (six signals) in comparison with vertical vibration on the seat surface.

Whole Body Vibration Exposure of Surface Coal Mining Machine Operators

1984 ◽  
Author(s):  
Paul J. Remington ◽  
Douglas W. Andersen ◽  
Gerald Redmond ◽  
Roy Bartholomae
Keyword(s):  
Coal Mining ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Mining Machine ◽  
Vibration Exposure ◽  
Body Vibration ◽  
Surface Coal Mining ◽  
Machine Operators

Aero-Engine Vibration Fault Diagnosis Based on Harmonic Wavelet

2012 ◽  
Vol 490-495 ◽  
pp. 218-222
Author(s):  
Tao Xu ◽  
Yan Jin ◽  
Jin Xu
Keyword(s):  
Fault Diagnosis ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Body Vibration ◽  
Time Frequency ◽  
Vibration Data ◽  
Engine Vibration ◽  
Aero Engine ◽  
Harmonic Wavelet ◽  
Vibration Experiment

Because of the complicated structure of rollers, it is very difficult to diagnosis aero-engine vibration fault. Harmonic wavelet method is proposed target towards whole-body vibration of aero-engine in this paper. To implement vibration fault diagnosis of Aero-engine, vibration signals are presented with time-frequency and spectrum of coefficients after harmonic wavelet transform. The designed method overcome noise disturbance and energy leakage and possesses better performance for aero-engine vibration analysis compared with traditional wavelet analysis method. With the vibration data from whole-body vibration experiment, the effectiveness of the designed method is illustrated and it could identify three classical vibration faulty modes accurately, which provides a better method for whole-body vibration fault diagnosis of Aero-engine.

Whole-Body Vibration Exposures in Undeground Coal Mining Operations

2016 ◽  
Vol 60 (1) ◽  
pp. 914-918
Author(s):  
D. Lynas ◽  
R. Burgess-Limerick
Keyword(s):  
Coal Mining ◽  
Underground Mining ◽  
Coal Mines ◽  
Whole Body Vibration ◽  
Electrical Equipment ◽  
Whole Body ◽  
Mining Equipment ◽  
Mining Operations ◽  
Body Vibration ◽  
Underground Coal Mines

Studies conducted on surface coal mining equipment have identified whole-body vibration as a significant hazard. Operators of underground mobile equipment, particularly shuttle cars and transport vehicles, are likely to be exposed to significant levels of whole-body vibration. To date, measuring whole-body vibration from underground mining mobile equipment has been difficult due to the strict guidelines governing the use of electrical equipment in underground mines. This paper presents data obtained from two low-methane coal mines using an iOS application installed on iPod Touch devices. The majority of measurements taken from a range of mobile plant and equipment in use at the underground coal mines exceeded the ISO2631.1 Health Guidance Caution Zone. Further investigations are being undertaken to develop a thorough understanding of whole-body vibration exposures to which operators of mobile equipment used in underground coal mines are exposed and the opportunities for application of this information to assist mine site safety, health and risk management processes.

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