Academic literature on the topic 'Iso 2631-1 1997'

This research expects to investigate yet at domestic-dump truck driver, carry on the preliminary vibration determination. This research studies ten dump trucks in Yunlin County and precede questionnaire at the sandstone field. The ISO 2631-1:1997 and Article 301 in Taiwan’s regulation “Rules of Equipment and Measures for Protecting Labors’ Safety and Health” are used to evaluate tolerable exposure time per day for drivers. And in accordance with ISO 2631-5:2004 to assessment healthy risk for dump truck driver. In accordance with Article 301 of Labor Safety and Health regulation in Taiwan’s to estimate tolerable exposure time. A half tolerable exposure time present lower than 8 hours. In accordance with ISO 2631-1:1997 to estimate tolerable exposure time, no matter use equation B.1 or B.2 to calculate tri-axis compose acceleration. All tolerable exposure time present lower than 8 hours. If basis of ISO 2631-5:2004 to evaluation healthy risk for driver.

The paper compares measurement-based measures for human vibration exposure. Data were collected during sea trials on a 10 m, 50 kn coastguard craft equipped with a three-axial accelerometer at the coxswain seat and with vertically mounted gauges measuring the acceleration of the cockpit floor. The ISO 2631-1:1997 measures of vibration (namely the root-mean-square (r.m.s.) value of the whole-body vibration (determined from the frequency-weighted acceleration signal), the maximum transient vibration value (MTVV), and the vibration dose value), the ISO 2631-5:2004 measure (namely the daily equivalent static compression dose Sed), and also statistically based measures to evaluate the acceleration magnitude are compared and discussed with respect to their ability to identify the mitigating effect of the suspension seat and how the different measures rank the severity of the high-speed craft (HSC) ride. The paper concludes that the r.m.s. value and the MTVV are unsuitable for evaluation of the conditions aboard while the other investigated measures show potential in this respect. Further the approach of ISO 2631-5:2004 taking both the short-term and the long-term perspectives on the human exposure to vibration is concluded to be the most mature method well suited to evaluation of HSC conditions.

Whole-body vibration exposure levels were measured during the operation of fifteen different types of mobile mining equipment commonly used in Ontario mines. A tri-axial seat pad accelerometer was used to measure vibration exposure when the mining vehicle was operated from a seated position and a tri-axial accelerometer secured to floor, between the operator's feet, was used to measure vibration exposure when the mining equipment was operated from a standing position. Measurements were conducted in accordance with the procedures described in the 1997 ISO 2631-1 standard. Determination of likely health risks for equipment operators were based on a comparison of the measured vibration exposure levels with Health Guidance Caution Zone limits presented in Annex B of the ISO 2631-1 standard. Six vehicles (UG haulage truck, bulldozer, 3.5 yard LHD, cavo loader, muck machine, and personnel carrying tractor) were above the Health Guidance Caution Zone limit, assuming an eight hour exposure period while four vehicles (grader, 7 yard LHD, scissor lift truck and locomotive) were within the Health Guidance Caution Zone limit.

Vibration is experienced when a body is subjected to either internal or external forces which cause oscillation, with most operators of industrial equipment often exposed to high dosage, higher than the stipulated values. In this research, Digital Real-Time Frequency Analyzer (RSA 5106A) was used, while the results obtained were evaluated and compared with the health guidelines of the ISO 2631-1 : 1997 and ISO 2631-5 : 2004 standards, as described in the Health Guidance Caution Zone for a daily exposure action value (EAV) of 0.47 m/s2 and a daily exposure limit value (ELV) of 0.93 m/s. High acceleration was mostly seen on the z-axis in all the results obtained, whereas many were not within the HGCZ (Arms <0.47, and >0.93 m/s2). Comparing (VDV <8.5 m/s1.75 and >17 m/s1.75) with the ISO standard, the accelerations on all x- and y-axes were slightly within the HGCZ, with just a little below 0.47 m/s2 limit. The results obtained clearly showed that urgent action is needed virtually on all the equipment in both the Secondary Manufacturing Department (SMD) and Primary Manufacturing Department (PMD) to minimize vibration exposure on the technical operators.

Buses are one of the important public transportation in Malaysia and commonly important for the student in any university. Thus, the study about Whole-Body Vibration (WBV) exposure induces to Low Back Pain (LBP) among the Universiti Tun Hussein Onn Malaysia (UTHM) was done. The objective was determine whether the bus drivers in UTHM would exceed the exposure action and limit values from the ISO 2631-1 (1997) during the working hours. Data collected according to different type of buses and evaluated the vibration significant different between buses based on the subjective correlation due to WBV questionnaire analysis. Analyze the prevalence of LBP based on the measurement and the questionnaire analysis. The study based on the international standard ISO 2631-1 (1997) which is related to the root-men-square (r.m.s) and Vibration Dose Value (VDV) parameter. The study covered among the bus drivers in UTHM. The measurement tools involved in the study is Larson Davis Vibration Meter (HVM 100) with Tri-axial Seat Pad Accelerometer to record data collection. The BLAZE software analyze the vibration exposure exceed the total vibration exposure according to 8 hours day A(8) value of 1.15 m/s2 and VDV value of 21.0 m/s1.75. The IBM Statistical Package for Social Science (SPSS) was used to do statistical analysis and testing involved was correlation, regression and ANOVA. Result obtained shows the A(8) and VDV was under EAV with highest value of 0.520 m/s2 and12.65 m/s1.75. The highest contribution factors by the duration to complete single trip per day (α=0.500).The further re-assess of working schedule need to be done in order to control the exposure level toward drivers. The assessment should be done for every two years.

Buffeting response of a double-sided catwalk designed for Maputo Bridge was investigated considering wind load nonlinearity, geometric nonlinearity, and self-excited forces. Buffeting analysis was conducted in time domain using an APDL-developed program in ANSYS, and the results were compared with the buffeting response under the traditional linear method. The wind field was simulated using the spectra representation method. Aerostatic coefficients were obtained from section model wind tunnel test. Parameter study has been carried out to investigate the effects of cross bridge interval and the gantry rope diameter on buffeting response. Referring to the ISO 2631-1(1997) standard and the annoyance rate model, the comfort of catwalk due to wind-induced vibration was evaluated. The results indicate that traditional linear calculation methods will underestimate the buffeting response of the catwalk, and enlarging the gantry rope size as well as decreasing the cross bridge interval would increase the comfort level. Moreover, the effect of gantry rope diameter was obvious than that of cross bridge interval. Annoyance rate model can evaluate the comfort level quantitatively compared to the ISO standard.

Pedestrian-induced vibration comfort is an important factor affecting the serviceability of footbridges. This article proposes a smartphone-based evaluation system for pedestrian-induced footbridge vibration comfort, and the evaluation system consists of a data acquisition subsystem, management center subsystem, and smartphone client. Four technical challenges in the application of the evaluation system are solved: coordinates transformation, acceleration signal drift correction, signal filtering, and computation of the total weighted root mean square acceleration. To verify the validity of the proposed evaluation system, field experiments are carried out on the Forth Corridor Footbridge in Guangzhou. A comparison of the proposed system and the traditional methodology shows that the total weighted root mean square acceleration errors between smartphones and accelerometers are less than ±5%. In addition, the subjective feelings in the field experiments are in excellent agreement with the corresponding stipulation in ISO 2631-1:1997 (Amendment 1. International Standardization Organization, Geneva, 2010).

This study quantifies whole-body vibration on a range of mine machinery typically used in a South African open cast mine. The ISO 2631-1 (1997) standard was used in the computation of weighted root mean square (WRMS) and vibration dose values (VDVs) whereas the ISO 2631-5 (2004) standard was used in the computation of daily static compressive stress (Sed) and R factor values. Two methods have been used to evaluate the whole-body vibration on a wide range of equipment used in an open cast mine. There are two main parameters for each of the standards. The ISO 2631-1 (1997) standard utilises the daily exposure A(8) and VDV, whereas the new ISO 2631-5 (2004) standard methodology uses the parameters Sed and R factor. ISO 2631-1 (1997) is poor in taking account of transient shocks. This led to the development of ISO 2631-5 (2004). Signals were therefore generated in the laboratory to further explore the parameters of the two standards. Vibration signals of more-or-less steady periodic processes can be approximated by superposition of sinusoids. To investigate the effect of shocks on the WBV response parameters used in the two standards, a series of investigations were conducted using very simplified simulations to capture the essential nature of various operational conditions, and qualitatively explain the trends in the response parameters. Pure sinusoidal data was first generated without shocks and investigated. Subsequently, sinusoidal signals with higher amplitudes were generated and investigated. Sinusoidal signals with increasing shock amplitude up to and exceeding the crest factor of 9 based on ISO 2631-1 (1997) were generated and analyzed. Finally, simulated data with different shock magnitude for five typical example cases were then generated and analyzed. The pure sinusoidal data was artificially generated using the signal generator at different amplitudes and frequencies, which are similar to field observed frequencies to enable numerical investigation of parameters to be carried out. A subset of the data was selected based on frequencies and amplitudes obtained on the field so as to have a representative data set on which investigations were carried out. The two parameters of the two standard methodologies were computed using simulated sinusoidal signal data. The trends in each of the parameters corresponding to each of the standards were monitored using various scenarios obtained by varying the signal parameters and compared against each other. There was approximate proportional correlation between the two parameters (VDV and Sed) with varying degrees of slope for each scenario. The Sed and VDV parameters are plotted on the x- and y-axes respectively. The graphs with slope greater than 1 corresponded to signals with low or no shock content; whereas the graphs with slope less than 1 corresponded to high shock content. The shock parameters (VDV and Sed) corresponding to the ISO 2631-1 (1997)and ISO 2631-5 (2004) standard methodologies were computed from field data and compared to see if the same trend obtained from the numerically obtained sinusoidal signals could be validated. It was found that the there was a gradual band correlation with slope less than 1 between the VDV and Sed parameters corresponding to signals of high shock content thereby validating the numerical findings. Since little or no extensive epidemiological studies have been carried out on the new methodology; it is recommended that more epidemiological studies be done to determine the exposure action and exposure limit values with respect to shocks in the Sed parameter for the new ISO 2631-5 (2004) standard methodology. It is advisable that caution is taking when using the new ISO 2631-5 (2004) standard methodology in evaluating whole-body vibration measurements until the limits are properly established. It is suggested that the new standard be used along with the established ISO 2631-1 (1997) standard methodology. Copyright
Dissertation (MSc)--University of Pretoria, 2009.
Mechanical and Aeronautical Engineering
Unrestricted

Vibration exposure can occur at work, commuting between home and work, and in leisure activities. Any form of transportation will expose humans to some degree of vibration. Exposure to vibration can cause health problems, but more likely comfort problems. Health problems are normally related to back pain. Comfort on the other hand is related to both physiological and psychological factors, which can have a wide range of effects from a general annoyance to a reduced work capability. The standard ISO 2631-1 (1997) provides a guidance, which can be used to measure, evaluate and assess effects of whole-body vibration to discomfort. The standard allows several interpretations, which can lead to different results, as the standard does not provide an explicit guidance for selecting which axes and locations to measure and which averaging method to use for evaluating the axes. The suggested averaging method is the root mean square (r.m.s.) method, but additionally vibration dose value (VDV) can be used. This can lead to different results, as VDV emphasises shocks more than the r.m.s. method. The standard guides to measure and evaluate at least the seat translational axes, but the additional nine axes from the seat, backrest and floor are not mandatory. However, this can result in a different comfort value, as the values from the measured axes are combined. So taking into account all possible interpretations the assessment can vary significantly for the same environment. The selection of the averaging method is not a technical issue, as both methods are supported by all commercial equipment. However, it is rare that more than three axes are possible to be measured with typical whole-body vibration measurement equipment, thus the majority of studies have published results based on only the seat translational axes. Especially the rotational axes have been missing in most studies. The full method (i.e. using all possible axes to calculate the comfort value) of ISO 2631-1 (1997) has been rarely used and there is very little information on how accurate the method is for assessing discomfort in a multi-axis environment. There are only a few studies that have used the full method, but there are no known studies which have actually validated the full ISO 2631-1 method. The objective of the thesis was to validate and, if necessary, to improve the full method of the ISO 2631-1 standard for evaluating discomfort from whole-body vibration in a multi-axis environment. It was assumed that the ISO 2631-1 method can be used to predict discomfort in practice, but there are a relatively low number of studies to confirm this. Frequency weightings have been the focus of many published studies and it was assumed that these are broadly correct. Other aspects of the ISO 2631-1 method are the focus of this thesis. The goal was to keep a backward compatibility to previous studies and the current commercial equipment, thus several limitations were defined for the improvement of the standard. Several laboratory experiments, field measurements, and field and laboratory trials were conducted to validate the standard method. At first it was concluded that practical equipment for measuring 12-axis data was needed as there was no commercial system available. The equipment and software was validated in two experiments, which showed that simple and affordable components could be used to develop equipment for the full method. Even though the standard does not include information about a six-axis sensor for measuring both translational and rotational axes, there was a method to validate the sensor. The first field study included measuring several machines using all twelve axes. The analysis showed that the seat and backrest translational axes will contribute about 90 % of the overall vibration total value of the standard method, thus very little justification was found for including the seat rotational and floor translational axes. Similar results were found based on the data from the previous 12-axis studies. It was also found that the neglected axes could be compensated with a factor for estimating the overall vibration total value including all twelve axes. As the overall vibration total value is directly related to the number of used axes, the compensating factors can be used to compare results which used different axes. The laboratory trial confirmed the results from the field study, and it was concluded that sufficient accuracy to predict discomfort can be achieved using just the seat translational axes, even though the correlation improved when more axes were included. It was found that the evaluation of discomfort was improved by the use of the frequency weighting curves and the r.m.s. averaging method. However, as the multiplying factors degraded correlation, it was concluded that a new set of factors should be calculated. The new factors showed that a higher emphasis on the seat horizontal axes should be given (x=2.7, y=1.8 and z=1.0). The new factors improved the correlation systematically for all subjects. The field trial showed a similar trend, where optimised multiplying factors improved the correlation, but it was also noted that different multiplying factors are required for different environments, thus a procedure to optimise the standard method to different environments was developed. The trial showed systematic behaviour and the optimised multiplying factors were best for all subjects and groups. Keywords: Discomfort, whole-body vibration, standard, ISO 2631-1, multi-axis, multiplying factors

As vibracoes de corpo inteiro estao presentes em maquinas e ambientes, incluindo os meios de transportes e trabalho, como as aeronaves. No entanto, podem ser omitidas como fontes de fadiga e disturbios organicos. Os efeitos da vibracao de corpo inteiro (VCI) na tripulacao de helicoptero sao silenciosos e cumulativos. O objetivo deste estudo foi verificar quais niveis de vibracao estao submetidos os tripulantes de helicoptero do Corpo de Bombeiros Militar de Minas Gerais - CBMMG, estabelecendo onde estes niveis se enquadram na norma ISO 2631-1/1997 e Diretiva 2002/44/CE, que lidam sobre a questao de VCI. O CBMMG opera o helicoptero modelo Esquilo (H350). Para tanto foram feitas as mensuracoes na aeronave com um vibrometro que coleta dados em m/s², sendo os dados parametrizados para a aceleracao ponderada aw. Quanto aos valores de aceleracao, a avaliacao da vibracao diaria para um periodo relativo a oito horas - A (8), extrapolou o limite previsto de 1,15 m/s², ficando em 1,88 m/s² para pilotos e 1,33 m/s² para tripulantes. Para o Valor da Dose de Vibracao - VDV, os parametros medidos ficaram dentro de limite especificado (17 m/s²), tendo valor maximo de 9,8 m/s². Quanto ao nivel de conforto, previsto na ISO 2631-1/1997, valores acima de 2m/s² foram adquiridos, colocando algumas situacoes de voo como muito desconfortaveis, conforme a norma. Estes resultados contribuem de forma direta para o fator da fadiga de voo, fator contribuinte de presenca macica nos varios acidentes aeronauticos bem como nas enfermidades cronicas dos tripulantes de helicoptero, principalmente associados a coluna vertebral.,

Abstract This paper presents a smartphone-based ride quality assessment conducted on a VIA Rail route in the province of Ontario Canada. The vibration data were collected by different smartphones placed in different locations on the train. The levels of ride quality were subsequently quantified by the two commonly used indices recommended in the ISO 2631:1-1997, and BS EN 12299:2009 standards. The results show that using smartphones for ride quality yields reasonable assessment in a low-cost and convenient manner and identify that the major poor ride quality values are recorded at stiffness transitions such as bridges, level crossing and switches. Limitations of smartphone sensors, and the future plan for improvement of the use of smartphones for evaluation of ride quality has also been discussed.

Abstract The human body behaves like a vibrating physical system having mass, elastic and damping properties. In order to study the biodynamic behavior of the body, it is common practice to model the body as a lumped single or a multiple-degree-of-freedom (MDOF) system. Standards have been developed using the frequency-weighted root-mean-square (rms) acceleration input to the body as the primary measure of whole-body vibration exposure. In this paper, absorbed power during exposure to vertical whole-body vibration is considered as a potential indicator of the physical stress affecting comfort and health. A four-degree-of-freedom biodynamic model is chosen to represent the body and the absorbed power for the different body segments and the total body is computed. On the basis of the model and of the guidance provided in ISO 2631-1:1997 relating vibration exposure with health risk, computations are carried out to define a health guidance caution zone based on absorbed power.

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.

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). Some reports suggest that acceleration at the seat pan is greater than that at the floor, indicating that the seat may amplify the vibration (Johanning, et al., 2006; Mansfield, 2005; Oborne & Clarke, 1974; Transport, 1980). 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, some research reports that rail vehicles experience far more lateral vibratory motion than cars and trucks (Lundstrom & Lindberg, 1983). Many factors influence the impact of shock felt by the engineer including train speed, consist, engineer control skills, anticipation of the shock, motion amplitude, shock duration, and body posture. Shock events and vibration affect ride quality; however, shocks are less controllable by locomotive design. Common sources of mechanical shock are coupling and slack run-ins and run-outs (Multer, et al., 1998). While there are investigations of whole-body vibration (WBV) in locomotive cabs reported in the literature, there have been no studies to date that have examined long-haul continuous vibrations (> 16 hr). The authors describe a long-haul WBV study collected on a 2007 GE ES44DC locomotive. It is the first in a series of studies sponsored by the Federal Railroad Administration (FRA) to examine WBV and shock in locomotive cabs. 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. Data collection occurred over 550 track miles for 16hr 44min. 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. The research team collected and analyzed vibrations in accordance with ISO 2631-1 and ISO 2631-5. The results from the study as well as future planned long-haul studies will provide a benchmark set of WBV metrics that define the vibration environment of present-day locomotive operations.