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).

Long-Haul Whole-Body Vibration Assessment of Locomotive Cabs

2012 ◽  
Author(s):  
Amanda DiFiore ◽  
Abdullatif Zaouk ◽  
Samiullah Durrani ◽  
Neil Mansfield ◽  
John Punwani
Keyword(s):  
Structural Dynamics ◽  
Whole Body Vibration ◽  
Occupational Risk ◽  
International Standards ◽  
Whole Body ◽  
Ride Quality ◽  
Body Vibration ◽  
Rail Vehicles ◽  
Mechanical Shocks ◽  
Iso 2631

Locomotives produce vibrations and mechanical shocks from irregularities in the track, structural dynamics, the engines, the trucks, and train slack movement (Mansfield, 2005). The different directions of the irregularities give rise to car-body vibrations in multiple axes including the following: • longitudinal, or along the length of the train (x); • lateral, or the side-to-side direction of the train (y); • vertical (z). The structural dynamics of rail vehicles give rise to several resonances in the 0.5–20Hz frequency range (Andersson, et al., 2005). Resonances are frequencies in the locomotive that cause larger amplitude oscillations. At these frequencies, even small-amplitude input vibration can produce large output oscillations. Further exacerbating the vibration environment, coupling of the axes of movement occurs: Motions in one direction contribute to motion in a different direction. The magnitude of vertical vibration in rail vehicles is reportedly well below many other types of vehicles (Dupuis & Zerlett, 1986; Griffin, 1990; Johanning, 1998). However, a lack of data from long-haul freight operations prevents an adequate characterization of the vibration environment of locomotive cabs. The authors describe results from 2 long-haul whole-body vibration (WBV) studies collected on a 2009 GE ES44C4 locomotive and a 2008 EMD SD70ACe. These WBV studies sponsored by the Federal Railroad Administration (FRA) examined WBV and shock in locomotives over 123 hours and 2274 track miles. The researchers recorded vibration data using 2 triaxial accelerometers on the engineers’ seat: a seat pad accelerometer placed on the seat cushion and a frame accelerometer attached to the seat frame at the base. The research team collected and analyzed vibrations in accordance with ISO 2631-1 and ISO 2631-5. ISO 2631-1 defines methods for the measurement of periodic, random and transient WBV. The focus of ISO 2631-5 is to evaluate the exposure of a seated person to multiple mechanical shocks from seat pad measurements. Exposure to excessive vibration is associated with an increased occupational risk of fatigue-related musculoskeletal injury and disruption of the vestibular system. While this is not an established causal relationship, it is possible that vibration approaching the ISO 2631-1 health caution guidance zones may lead to an increased occupational risk. The results from these rides show that the frequency-weighted ISO 2631 metrics are below the established health guidance caution zones of the WBV ISO 2631 standards. The goals of these studies are to: • collect data in accordance with international standards so results can be compared with similar findings in the literature for shorter duration rides as well as vibration studies in other transportation modes, • to characterize vibration and shock in a representative sample of locomotive operations to be able to generalize the results across the industry, and • collect benchmark data for future locomotive cab ride-quality standards.

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.

Acceptable Levels of Vibration on Ships

1973 ◽  
Vol 10 (02) ◽  
pp. 105-111
Author(s):  
F. Everett Reed
Keyword(s):  
Human Exposure ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Exposure Limits ◽  
Body Vibration ◽  
International Standard ◽  
Time Exposure ◽  
Proficiency Level ◽  
Draft International Standard ◽  
Sound Foundation

The Draft International Standard ISO/DIS 2631 "Guide for the Evaluation of Human Exposure to Whole-Body Vibration" provides an excellent base for setting acceptable levels of vibration on ships.2 A standard for evaluating vibration levels has been needed for some time and the new standard not only provides a sound foundation for evaluating vibration, but also permits the vibration levels to be rated numerically as percentages of the established standard of fatigue-decreased proficiency. The standard is related to frequency, direction of motion, and the time exposure at the different locations in the ship. "Safe exposure limits" and "reduced comfort limits" are defined in terms of percentages of this same fatigue-decreased proficiency level.

Cross-sectional Analysis of Whole Body Vibration Exposures and Health Status among Long-haul Truck Drivers

2016 ◽  
Vol 60 (1) ◽  
pp. 928-932 ◽  
Author(s):  
Jeong Ho Kim ◽  
Monica Zigman ◽  
Jack T Dennerlein ◽  
Peter W Johnson
Keyword(s):  
Health Status ◽  
Health Outcomes ◽  
Short Form ◽  
Whole Body Vibration ◽  
Truck Drivers ◽  
International Standards ◽  
Whole Body ◽  
Low Back ◽  
Body Vibration ◽  
Daily Exposure

Exposure to whole body vibration (WBV) is known to be associated with various adverse health outcomes among professional truck drivers. As a part of a randomized controlled trial, this study evaluated WBV exposures and various health outcomes from 96 professional truck drivers. The WBV was measured and analyzed per International Standards Organization (ISO) 2631-1 and 2631-5 WBV standards. This study also measured self-reported regional body pain (10-point scale), low back disability (the Oswestry Disability Index), and physical/mental health (the Short Form 12-item Health Survey). Lastly, this study evaluated associations between the WBV exposure and various health outcomes. The results showed that the predominant z-axis weighted average vibration [A(8)] measure (Mean ± SE: 0.35 ± 0.01 m/s2) was below the ISO and European Union (EU) daily exposure action limits (0.5 m/s2) whereas the vibration dose value [VDV(8)] measure (12.2 ± 0.3 m/s1.75) was above the ISO and EU daily exposure action limit (9.1 m/s1.75). Self-reported low back pain (LBP) was the most prevalent adverse musculoskeletal outcome reported (72.5%) with average LBP score of 2.9 (SD: 2.0). The SF-12 health scores showed that truck drivers’ physical health status was lower than the average US population (p’s < 0.04). Moreover, the Spearman’s correlations ( rs ) between the WBV parameters and health outcomes indicated that A(8) measures were associated with LBP ( rs = 0.31; r = 0.05) and SF-12 physical composite score ( rs = −0.39; r = 0.02); however VDV(8) was not associated with any of the health outcomes. The study findings indicates that although the impulsive exposures [VDV(8)] were more prominent, the continuous, average vibration [A(8)] appears to be more strongly associated with injury risks. This finding supports the practice of EU countries using A(8) as one of the primary measures for characterizing daily WBV exposures but also complements many other studies indicating that the current EU daily action limit value of 0.50 m/s2 for WBV may be too high.

Investigation of Whole Body Vibration on Urban Midi Bus

2014 ◽  
Vol 592-594 ◽  
pp. 2066-2070 ◽  
Author(s):  
M. Rao Jaganmohan ◽  
S.P. Sivapirakasham ◽  
K.R. Balasubramanian ◽  
K.T. Sreenath
Keyword(s):  
Resonance Effect ◽  
Whole Body Vibration ◽  
Dynamic Test ◽  
Rear Seat ◽  
Operating Conditions ◽  
Whole Body ◽  
Static Test ◽  
Body Vibration ◽  
Exposure Limit ◽  
Vibration Magnitude

The objective of the study is to measure the whole body vibration (WBV) transmitted to the driver as well as the passengers during the operation of bus and to compare results with ISO 2631-1(1997) comfort chart and health guidance criteria. In this study, vibration exposure of the driver, passenger in the mid row seat and passenger in the rear row seat were measured at different operating conditions (static and dynamic). The BMI (Body Mass Index) was maintained for driver and passengers. The results of static test showed that the driver seat produced more vibrations compared to the passenger's mid row and rear row seat. This is due to the fact that driver seat was positioned close to the engine cabin. The results of dynamic test showed that, in all cases, the rear seat produced maximum vibrations. At 40 km/h speed the vibration magnitude exceeded the exposure limit at all tested seats. This high vibration magnitude might be due to the resonance effect caused between engine and chassis vibrations.

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