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.

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 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.

A Methodology for the Test Design and Evaluation of Human Whole-Body Vibration in Ground Vehicle Systems

1989 ◽  
Vol 33 (18) ◽  
pp. 1192-1196
Author(s):  
Ellen C. Haas
Keyword(s):  
Whole Body Vibration ◽  
International Standards ◽  
Whole Body ◽  
Test Design ◽  
Exposure Limits ◽  
Ground Vehicle ◽  
Body Vibration ◽  
Exposure Limit ◽  
Vehicle Systems ◽  
Iso 2631

To date, testing and evaluation of whole-body vibration in ground vehicle systems have not always fully utilized appropriate experimental design methodology, applicable statistical tests, or relevant criteria. A test design and evaluation methodology was developed to eliminate these oversights. This methodology uses inferential statistics, questionnaires, and a comparison of vibration data with representative mission scenarios. The methodology was employed in the evaluation of two alternative tracked ground vehicle designs. The independent variables were track type, terrain, vehicle speed, and crew position. The dependent variables were International Standards Organization (ISO) 2631 whole-body vibration exposure limit times at the lateral, transverse, and vertical axes. Two different multivariate analyses of variance (MANOVAs) performed on the exposure limit data indicated that all main effects, as well as several interactions, were significant (p < .01). A comparison of exposure limits to a representative mission scenario indicated that both track types would exceed ISO 2631 exposure, comfort, and fatigue limits during expected travel over cross-country terrain. Crew questionnaires also indicated crew discomfort when exposed to this type of terrain. The experiment demonstrated that the procedure was useful in helping to determine the extent that vehicle vibration permits the performance of the vehicle mission, within limits dictated by safety, efficiency, and comfort.

scholarly journals Whole Body Vibration Analysis of Baby Hammock

2018 ◽  
Vol 217 ◽  
pp. 01005
Author(s):  
Ying Hao Ko ◽  
Chia Sin Geh
Keyword(s):  
High Speed ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Asian Countries ◽  
Body Vibration ◽  
Limit Value ◽  
Exposure Limit ◽  
Rocking Motion ◽  
Action Value ◽  
Iso 2631

Studies have been carried on the effect of rocking on a baby and concluded that baby sleeps easier while being rocked. In Malaysia, as in many Southeast Asian Countries, it is common to put babies to sleep in a baby hammock. the vertical rocking motion generated by baby hammock has exposed babies to whole-body vibration (WBV). It has been shown by ISO2631 (1997) that WBV may lead the discomfort and adverse effect on health. Standards have been set by ISO 2631 (1997) concerning the WBV for people in a recumbent position and consider weighted vibrations of more than 2 m/s2 to be extremely uncomfortable. However, standards concerning the allowable amount vibrations a baby in a baby hammock can safety endure are currently lacking. WBV analysis of the baby hammock with the weight ranged from 3kg to 14kg is conducted. For each measurement, four conditions are considered: manual rocking, auto rocking with low, medium and high speed. In this study, average root-mean-square values for the acceleration were found to be at a maximum of 2.46 m/s2, and to be above the extremely uncomfortable level. This study develops a baseline exposure time for the baby hammock before it reaches the safety values of exposure action value (EAV) and exposure limit value (ELV) set by ISO 2631(1997).

scholarly journals Assessment of whole-body vibration exposure of mining truck drivers

2020 ◽  
Vol 120 (9) ◽  
Author(s):  
B. Erdem ◽  
T. Dogan ◽  
Z. Duran
Keyword(s):  
Health Effect ◽  
Whole Body Vibration ◽  
Correlation Coefficients ◽  
Dominant Frequency ◽  
Truck Drivers ◽  
Whole Body ◽  
Vibration Acceleration ◽  
Body Vibration ◽  
Dump Trucks ◽  
Iso 2631

SYNOPSIS Whole-body vibration (WBV) exposure measurements taken from 105 truck drivers employed in 19 mines and other workplaces were evaluated with the criteria prescribed in EU 2002/44/EC directive, BS 6841 (1987), ISO 2631-1 (1997). and ISO 2631-5 (2004) standards. The highest vibration acceleration was measured on the vertical Z-axis. The highest WBV exposure occurred in the RETURN, HAUL, and SPOT phases while the lowest exposure took place in the LOAD and WAIT phases. Crest factors on all axes were generally greater than nine, yet strong correlation coefficients were achieved in VDV-eVDV analyses. Driver seats generally dampened the vibration along the Z-axis but exacerbated it along X and Y axes. The dominant frequency for the X and Y-axes rose up to 40 Hz while it ranged between 1 Hz and 2.5 Hz along the Z-axis. While the probability of an adverse health effect was higher with BS 6841 (1987) and ISO 2631-1 (1997) standards, it was low according to EU 2002/44/EC and ISO 2631-5 (2004). The 91 t, 100 t, and 170 t capacity trucks produced lower vibration magnitudes. Drivers were exposed to approximately equivalent levels of WBV acceleration and dose in contractor-type trucks and mining trucks. Rear-dump trucks exposed their drivers to a slightly higher level of vibration than bottom-dump trucks. Underground trucks exposed their drivers to a significantly higher level of vibration than mining trucks. Both driver age and driver experience were inversely proportional to vibration acceleration and dose. Conversely, there was a positive relationship between the truck service years and the WBV acceleration and dose to which drivers were exposed to. Loads of blocky material exposed drivers to higher vibration acceleration and dose levels than non-blocky material. Keywords: whole-body vibration, mining truck, A(8), BS 6841, EU 2002/EC/44, ISO 2631-1, ISO 2631-5, VDV(8).

scholarly journals Occupational Vibration in Urban Bus and Influence on Driver’s Lower Limbs

2018 ◽  
Vol 4 (1) ◽  
pp. 56-66
Author(s):  
M. Cvetkovic ◽  
J. Santos Baptista ◽  
M. A. Pires Vaz
Keyword(s):  
Whole Body Vibration ◽  
Working Environment ◽  
Lower Limbs ◽  
Whole Body ◽  
Body Vibration ◽  
Prisma Statement ◽  
Physical Changes ◽  
Iso 2631 ◽  
The Impact ◽  
Whole Body Vibrations

The whole-body vibration occurs in many occupational activities, promoting discomfort in the working environment and inducing a variety of psycho – physical changes where consequences as a permanent dysfunction of certain parts of the organism may occur. The main goal of this short systematic review is finding the articles with the most reliable results relating whole-body vibrations to buses and, to compare them with the results of drivers’ lower limbs musculoskeletal disease which occurs as a consequence of many year exposure. PRISMA Statement Methodology was used and thereby 27 Scientific Journals and 25 Index - Database were searched through where 3996 works were found, of which 24 were included in this paper. As a leading standard for analysis of the whole-body vibration the ISO 2631 – 1 is used, while in some papers as an additional standard the ISO 2631-5 is also used for the sake of better understanding the vibrations. Furthermore, the European Directive 2002/44 / EC is included where a daily action exposure to the whole-body vibrations is exactly deter-mined. All the results presented in the paper were compared with the aforesaid standards. After having searched the databases, papers that deal with research of the impact of the vibration on the driver’s lower limbs did not contain any information’s on the described problem.

Reducing whole-body vibration and musculoskeletal injury with a new car seat design

Ergonomics ◽  
2005 ◽  
Vol 48 (9) ◽  
pp. 1183-1199 ◽  
Author(s):  
M. Makhsous ◽  
R. Hendrix ◽  
Z. Crowther ◽  
E. Nam ◽  
F. Lin
Keyword(s):  
Whole Body Vibration ◽  
Musculoskeletal Injury ◽  
Whole Body ◽  
Body Vibration ◽  
Car Seat
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