中国男性青年坐姿Z轴振动频率计权曲线
作者：彭绍平 李盈忠 韩宜保 肖艳华
单位：彭绍平.航天医学工程研究所，北京 100094
关键词：振动应激；人体；坐姿；Z轴振动；频率计权；等振动感觉曲线
航天医学与医学工程000302A Frequency Weighting Contour for Chinese Young Males
PENG Shao-ping,LI Ying-zhong,HAN Yi-bao,XIAO Yan-hua
(Institute of Space Medico-Engineering,Beijing 100094,China)
Abstract: Objective To obtain the frequency weighting contour for seated Chinese young males in z axis.Method 10 male volunteers served as the subjects.They were exposed to standard vibration stimulus (a sinusoidal vibration of 1.0 m/s2 at 8 Hz) and 14 kinds of sinusoidal experimental vibration stimuli at frequencies from 4 Hz to 80 Hz.The magnitude of the experimental vibration stimulus was changed by the subject through a signal condition and switching device made by ourselves to obtain an equal vibration sensation to the standard vibration.The data were fitted to the same form of the frequency weighting Wk of ISO 2631-1 with the least square method and optimization of parameters.Result Compared with ISO 2631-1,the frequencies weightings of Chinese young males at 16～80 Hz are significantly higher than those of ISO 2631-1(P<0.005),but there are no significant difference between two frequency weighting contours at other frequencies. Conclusion Chinese young males are more sensitive to vibration at 16～80 Hz in Z axis.
, 百拇医药
Key words:vibrational stress;human body;sitting position;z axis vibration;frequency weighting;equal vibration sensation contour
摘要：目的 获取中国男性青年坐姿Z轴振动的频率计权曲线。方法 被试者为10名男性青年，身体健康。实验采用对偶法。标准激励为频率8 Hz、加速度1.0 m/s2的正弦振动，实验激励也是正弦振动，频率为4～80 Hz，共14种。被试者自然放松地坐在实验座椅上，座椅刚性地固定在振动台面上。被试者首先承受标准激励，获得一个振动感觉，然后承受实验激励，用信号调节与切换装置调节其强度，直到获得与标准激励相同的振动感觉为止。再用振动信号记录系统记录此时实验激励的振动加速度的均方根值。将记录的数据利用最小二乘和优化设计的方法拟合成振动频率计权曲线。结果 所得到的振动频率计权在16～80 Hz显著地大于ISO 2631-1相应的频率计权(P<0.005)，在其它频率上则无显著差异。 结论 坐姿中国男性青年对16～80 Hz的Z轴振动比ISO 2631-1规定的更敏感。
, http://www.100md.com
中图法分类号：R852.25 文献标识码：A 文章编号：1002-0837(2000)03-0162-04
Vibration is often complex,contains many frequencies,occurs in several directions and changes over time.The effects of vibration on human may be manifold (health,working proficiency,comfort,and so on) and changeful[1].Thus,it is difficult to choose a fixed program for evaluation of vibration.
For whole-body vibration,ISO 2631-1:1997(Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-art 1: General requirements) is a guidance.This standard defined the evaluation methods based on the frequency weighting contours,and the frequency weighting contours are its core and base[1].
, http://www.100md.com
However,there are no data of Chinese people to be incorporated into the frequency weighting contours of ISO 2631-1:1997.It is difficult to obtain the frequency weighing contours directly.But it is closely related to the equal vibration sensation contour,which is a vibration value of equal vibration sensation as a function of frequency.By the way,the vibration value can be described with displacement,velocity,acceleration,and so on,and it is described with acceleration in this paper.
, 百拇医药
If the posture of a person,the direction of vibration and the parameter describing vibration value of the equal vibration sensation contour are the same as those of the frequency weighting contour,then E(f)。W(f)=k[2,3].
Where f-frequency of vibration;
E(f)-equal vibration sensation contour;
W(f)-frequency weighting contour;
k-constant and is not related to f.
, http://www.100md.com
Therefore,we can obtain the frequency weighting contour from the equal vibration sensation contour.The present work is to study the equal vibration sensation contour of Chinese seated people in Z axis and to obtain the frequency weighting contour for them from the equal vibration sensation contour.
Method
Subjects Ten young male volunteers served as the subjects.None of them had occupationally experienced whole-body vibration previously.They were 19.5±1.7 years old,1.71±0.02 meters tall and their weights were 63.9±4.1 kilograms.
, 百拇医药
Apparatus The apparatuses were in table 1.
Table 1 Apparatuses apparatus
number
model
vibrator and its control system
1
EVH-4
accelerometer
2
B.K.4370
, 百拇医药 charge amplifier
2
B.K.2635
vibration meter
1
B.K.2511
signal condition and switching device
1
Procedure The sketch of the experimental procedure was shown in Fig 1.
, 百拇医药
Fig.1 Sketch of the experiment
In the first experimental session,the subjects were instructed to do the experiment according to the procedure.They were asked to sit in a chair which was fixed on the vibra-tor.All input vibration stimuli were sinusoidal in Z axis,and the standard vibration stimulus was a vibration of 1.0m/s2 at 8Hz.The frequencies of the experimental vibration stimuli were 4,5,6.3,8,10,12.5,16,20,25,31.5,40,50,63,80 Hz(All the vibration were no harm to the human body).
, http://www.100md.com
Every volunteer was first exposed to the standard vibration stimulus to obtain a standard vibration sensation,and then was randomly exposed to the experimental vibration stimulus and was asked to change the magnitude of the experimental vibration stimulus by means of the signal condition and switching device made by ourselves until an equal vibration sensation to the standard vibration stimulus was obtained(If someone forgot the sensation of the standard vibration stimulus in this procedure,he could switch to the standard vibration stimulus by means of the signal condition and switching device).And then the experimental vibration stimulus was recorded by the vibration meter,BK 2511.The experimental vibration stimulus at every frequency was selected for two times by every volunteer,and the result was the mean of the results of two times.The frequency of experimental vibration stimulus was randomly selected and the whole procedure was repeated until all the frequencies mentioned above had been selected.
, http://www.100md.com
Data processing As a result,14 experimental vibration stimuli for every volunteer which had equal vibration sensation to the standard vibration stimulus were obtained.We defined ai(Fj) to indicate the experimental vibration stimulus at frequency of Fj which was the equal vibration sensation to the standard vibration stimulus for the i th volunteer.
We think that the form of the frequency weighting contour for seated Chinese young males in Z axis is the same as the form of Wk,a frequency weighting contour of ISO 2631-1 for seating position in Z axis,and that their parameters are different.In order to fit the data to the form and gain the pa-rameters for Chinese young males,We defined a function:Where a(Fj)=
, 百拇医药
H(Fj,f3，f4,f5,f6,Q4,Q5,Q6)=Hh(Fj)He(Fj)Ht(Fj,f3,f4,Q4)Hs(Fj,f5,f6,Q5,Q6),it is the form of the frequency weighting contour for seated Chinese young males in Z axis and Wk,a frequency weighting contour of ISO 2631-1 for seating position in Z axis.
, 百拇医药
norm=1.036,it was a normalization factor and changed the experimental vibration sensation to the level of Wk.
And then we used the least square method and optimization of parameters to fit the curve.
Result
The root-mean-square(rms.) of accelerations of the experimental vibration stimuli are shown in Table 2.
The frequency weighting contour for seated Chinese young males in z axis is
, 百拇医药
the values of parameters are as follows:
f3=0.0100223 f4=12.5615
f5=2.84465 f6=1.8806
Q4=0.000513965
Q5=0.0986939 Q6=0.109545
And the equal vibration sensation contour is 1/H(f).
The frequency weighting contour for seated Chinese young males in z axis and the frequency weighting contour Wk of ISO 2631-1 are shown in Fig.2.
, 百拇医药
Fig.2.Frequency weighting contours
——this experiment；-。-ISO 2631-1
Table 2 Experimental vibration stimuli of equal sensation(rms.) f
(Hz)
volunteer
mean
standard error
1
2
3
, http://www.100md.com
4
5
6
7
8
9
10
4
0.745
1.035
1.200
1.300
0.865
, http://www.100md.com 0.925
0.755
1.170
1.250
1.940
1.1185
0.3519
5
0.650
0.880
1.040
1.075
0.865
, http://www.100md.com
0.915
0.920
0.890
1.065
1.105
0.9405
0.1366
6.3
0.685
0.950
1.120
1.285
0.815
, 百拇医药
0.840
0.930
0.900
0.865
0.845
0.9235
0.1686
8
1.040
0.970
0.945
0.950
1.045
, http://www.100md.com
0.950
0.930
0.965
1.180
0.955
0.993
0.07646
10
1.045
1.140
1.175
1.130
1.230
, 百拇医药
1.050
1.300
1.050
1.075
0.725
1.092
0.1541
12.5
1.240
1.255
1.085
1.080
1.055
, http://www.100md.com
1.070
1.110
1.230
1.030
0.815
1.097
0.1292
16
1.215
1.045
1.315
0.810
0.910
, 百拇医药
1.130
1.250
1.360
0.535
0.485
1.0055
0.3130
20
1.640
1.220
1.710
1.300
1.005
, 百拇医药
1.105
1.250
1.410
0.570
0.605
1.1815
0.3808
25
2.190
1.560
2.110
1.410
1.145
, http://www.100md.com
1.685
1.355
0.930
0.550
0.710
1.3645
0.5486
31.5
1.855
1.355
1.935
1.290
1.215
, 百拇医药
1.210
1.220
1.505
0.625
0.955
1.3165
0.3873
40
2.190
1.360
2.000
1.840
1.400
, http://www.100md.com
1.460
1.455
1.645
0.770
0.905
1.5025
0.4451
50
2.460
1.610
2.630
1.475
2.155
, http://www.100md.com
1.395
1.360
1.650
0.705
0.600
1.604
0.6689
63
2.650
1.400
2.155
2.520
1.925
, http://www.100md.com
1.415
1.775
1.675
0.655
1.135
1.7305
0.6157
80
2.490
1.705
2.395
1.955
1.515
, 百拇医药
1.135
1.560
2.150
0.980
0.960
1.6845
0.5589
Compared with ISO 2631-1,the frequency weightings of Chinese young males at 16～80Hz are significantly higher than those of ISO 2631-1(P<0.005),and there are no significant difference between two frequency weighting contours at other frequencies.In other words,Chinese young males are more sensitive to the vibration at 16～80Hz.Discussion
, 百拇医药
The frequency weightings and the vibration sensation are related to the effects of vibration on the human body and transmissibility of the human body.In general,a human body can be regarded as one or more spring-mass system with viscous damping.For a spring-mass system with viscous damping,its equation of motion is:
Where:t—time;
x—the displacement of the system;
, http://www.100md.com
m—the mass of the system;
k—the stiffness of the system;
c—the viscous damping coefficient of the system;
F—the magnitude of force acting on the system;
f—the frequency of the force.
The acceleration resonance frequency of the system is
If the frequency of the force is near to the acceleration resonance frequency of the system,the acceleration of the system is greater and the transmissibility to the system is higher than those when the frequency of the force is far from it.In general,
<<1,so the smaller the m the higher the acceleration resonance frequency,and the larger the k the higher the acceleration resonance frequency.For a thin person,m is usually smaller than that of fat one and k usually is larger than that of fat one,and his acceleration resonance frequency will be higher than that of the fat one.Hence,the effects of vibration on a thin person at higher frequencies are more considerable than that on a fat one and the transmissibility of vibration to a thin human body at higher frequencies is higher than that to a fat human body.In fact,for Chinese,there are three acceleration resonance frequencies[4],5.59 Hz,11.24 Hz,26.89 Hz; but for those being similar to those covered in ISO 2631-1,there are only two acceleration resonance frequencies[5],5.78 Hz,and 10.76 Hz.Thus,at higher frequencies far from 10.76 Hz,the effects of vibration on Chinese should be more considerable than that on those covered in ISO 2631-1 and the transmissibility of vibration to their bodies should be higher than that to the bodies of those covered in ISO 2631-1.Because the volunteers in this paper are Chinese young males,they may be thinner and brawnier than those covered in ISO 2631-1 and the effects on them at higher frequencies may be more considerable and the transmissibility of vibration to their bodies at higher frequencies may be higher.Hence,they are more sensitive to the vibration at 16～80 Hz in z axis than those covered in ISO 2631-1.
, 百拇医药
[References]
[1] International standard ISO 2631-1-Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-Part 1: General requirements[S].1997
[2] Griffin MJ.Handbook of human vibration[M].London: Academic Press,1990:27～40
[3] Peng Shaoping,LI Yingzhong,Han Yibao et al.A study of equal vibration sensation contours of three waveforms vibration and the preliminary research on the application of the parameters for vibration evaluation[D].Beijing:Institute of Space Medico-Engineering,1999
, 百拇医药
彭绍平,李盈忠,韩宜保等.不同波形振动的等感研究和评价参数的应用探讨[D].[学位论文]北京：航天医学工程研究所，1999
[4] GB/T 16440-1996-Vibration and shock-Mechani-cal driving point impedance of the human body[S].Bejing:Standardization press of China,1996:2～6
中华人民共和国国家标准GB/T 16440-1996—振动与冲击 人体的机械驱动点阻抗[S].北京:中国标准出版社,1996:2～6
[5] International standard ISO 5982—Mechanical vibration and shock-Mechanical driving point impedance of the human body[S].1981
Received date:1999-09-16, 百拇医药
单位：彭绍平.航天医学工程研究所，北京 100094
关键词：振动应激；人体；坐姿；Z轴振动；频率计权；等振动感觉曲线
航天医学与医学工程000302A Frequency Weighting Contour for Chinese Young Males
PENG Shao-ping,LI Ying-zhong,HAN Yi-bao,XIAO Yan-hua
(Institute of Space Medico-Engineering,Beijing 100094,China)
Abstract: Objective To obtain the frequency weighting contour for seated Chinese young males in z axis.Method 10 male volunteers served as the subjects.They were exposed to standard vibration stimulus (a sinusoidal vibration of 1.0 m/s2 at 8 Hz) and 14 kinds of sinusoidal experimental vibration stimuli at frequencies from 4 Hz to 80 Hz.The magnitude of the experimental vibration stimulus was changed by the subject through a signal condition and switching device made by ourselves to obtain an equal vibration sensation to the standard vibration.The data were fitted to the same form of the frequency weighting Wk of ISO 2631-1 with the least square method and optimization of parameters.Result Compared with ISO 2631-1,the frequencies weightings of Chinese young males at 16～80 Hz are significantly higher than those of ISO 2631-1(P<0.005),but there are no significant difference between two frequency weighting contours at other frequencies. Conclusion Chinese young males are more sensitive to vibration at 16～80 Hz in Z axis.
, 百拇医药
Key words:vibrational stress;human body;sitting position;z axis vibration;frequency weighting;equal vibration sensation contour
摘要：目的 获取中国男性青年坐姿Z轴振动的频率计权曲线。方法 被试者为10名男性青年，身体健康。实验采用对偶法。标准激励为频率8 Hz、加速度1.0 m/s2的正弦振动，实验激励也是正弦振动，频率为4～80 Hz，共14种。被试者自然放松地坐在实验座椅上，座椅刚性地固定在振动台面上。被试者首先承受标准激励，获得一个振动感觉，然后承受实验激励，用信号调节与切换装置调节其强度，直到获得与标准激励相同的振动感觉为止。再用振动信号记录系统记录此时实验激励的振动加速度的均方根值。将记录的数据利用最小二乘和优化设计的方法拟合成振动频率计权曲线。结果 所得到的振动频率计权在16～80 Hz显著地大于ISO 2631-1相应的频率计权(P<0.005)，在其它频率上则无显著差异。 结论 坐姿中国男性青年对16～80 Hz的Z轴振动比ISO 2631-1规定的更敏感。
, http://www.100md.com
中图法分类号：R852.25 文献标识码：A 文章编号：1002-0837(2000)03-0162-04
Vibration is often complex,contains many frequencies,occurs in several directions and changes over time.The effects of vibration on human may be manifold (health,working proficiency,comfort,and so on) and changeful[1].Thus,it is difficult to choose a fixed program for evaluation of vibration.
For whole-body vibration,ISO 2631-1:1997(Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-art 1: General requirements) is a guidance.This standard defined the evaluation methods based on the frequency weighting contours,and the frequency weighting contours are its core and base[1].
, http://www.100md.com
However,there are no data of Chinese people to be incorporated into the frequency weighting contours of ISO 2631-1:1997.It is difficult to obtain the frequency weighing contours directly.But it is closely related to the equal vibration sensation contour,which is a vibration value of equal vibration sensation as a function of frequency.By the way,the vibration value can be described with displacement,velocity,acceleration,and so on,and it is described with acceleration in this paper.
, 百拇医药
If the posture of a person,the direction of vibration and the parameter describing vibration value of the equal vibration sensation contour are the same as those of the frequency weighting contour,then E(f)。W(f)=k[2,3].
Where f-frequency of vibration;
E(f)-equal vibration sensation contour;
W(f)-frequency weighting contour;
k-constant and is not related to f.
, http://www.100md.com
Therefore,we can obtain the frequency weighting contour from the equal vibration sensation contour.The present work is to study the equal vibration sensation contour of Chinese seated people in Z axis and to obtain the frequency weighting contour for them from the equal vibration sensation contour.
Method
Subjects Ten young male volunteers served as the subjects.None of them had occupationally experienced whole-body vibration previously.They were 19.5±1.7 years old,1.71±0.02 meters tall and their weights were 63.9±4.1 kilograms.
, 百拇医药
Apparatus The apparatuses were in table 1.
Table 1 Apparatuses apparatus
number
model
vibrator and its control system
1
EVH-4
accelerometer
2
B.K.4370
, 百拇医药 charge amplifier
2
B.K.2635
vibration meter
1
B.K.2511
signal condition and switching device
1
Procedure The sketch of the experimental procedure was shown in Fig 1.
, 百拇医药
Fig.1 Sketch of the experiment
In the first experimental session,the subjects were instructed to do the experiment according to the procedure.They were asked to sit in a chair which was fixed on the vibra-tor.All input vibration stimuli were sinusoidal in Z axis,and the standard vibration stimulus was a vibration of 1.0m/s2 at 8Hz.The frequencies of the experimental vibration stimuli were 4,5,6.3,8,10,12.5,16,20,25,31.5,40,50,63,80 Hz(All the vibration were no harm to the human body).
, http://www.100md.com
Every volunteer was first exposed to the standard vibration stimulus to obtain a standard vibration sensation,and then was randomly exposed to the experimental vibration stimulus and was asked to change the magnitude of the experimental vibration stimulus by means of the signal condition and switching device made by ourselves until an equal vibration sensation to the standard vibration stimulus was obtained(If someone forgot the sensation of the standard vibration stimulus in this procedure,he could switch to the standard vibration stimulus by means of the signal condition and switching device).And then the experimental vibration stimulus was recorded by the vibration meter,BK 2511.The experimental vibration stimulus at every frequency was selected for two times by every volunteer,and the result was the mean of the results of two times.The frequency of experimental vibration stimulus was randomly selected and the whole procedure was repeated until all the frequencies mentioned above had been selected.
, http://www.100md.com
Data processing As a result,14 experimental vibration stimuli for every volunteer which had equal vibration sensation to the standard vibration stimulus were obtained.We defined ai(Fj) to indicate the experimental vibration stimulus at frequency of Fj which was the equal vibration sensation to the standard vibration stimulus for the i th volunteer.
We think that the form of the frequency weighting contour for seated Chinese young males in Z axis is the same as the form of Wk,a frequency weighting contour of ISO 2631-1 for seating position in Z axis,and that their parameters are different.In order to fit the data to the form and gain the pa-rameters for Chinese young males,We defined a function:Where a(Fj)=
, 百拇医药
H(Fj,f3，f4,f5,f6,Q4,Q5,Q6)=Hh(Fj)He(Fj)Ht(Fj,f3,f4,Q4)Hs(Fj,f5,f6,Q5,Q6),it is the form of the frequency weighting contour for seated Chinese young males in Z axis and Wk,a frequency weighting contour of ISO 2631-1 for seating position in Z axis.
, 百拇医药
norm=1.036,it was a normalization factor and changed the experimental vibration sensation to the level of Wk.
And then we used the least square method and optimization of parameters to fit the curve.
Result
The root-mean-square(rms.) of accelerations of the experimental vibration stimuli are shown in Table 2.
The frequency weighting contour for seated Chinese young males in z axis is
, 百拇医药
the values of parameters are as follows:
f3=0.0100223 f4=12.5615
f5=2.84465 f6=1.8806
Q4=0.000513965
Q5=0.0986939 Q6=0.109545
And the equal vibration sensation contour is 1/H(f).
The frequency weighting contour for seated Chinese young males in z axis and the frequency weighting contour Wk of ISO 2631-1 are shown in Fig.2.
, 百拇医药
Fig.2.Frequency weighting contours
——this experiment；-。-ISO 2631-1
Table 2 Experimental vibration stimuli of equal sensation(rms.) f
(Hz)
volunteer
mean
standard error
1
2
3
, http://www.100md.com
4
5
6
7
8
9
10
4
0.745
1.035
1.200
1.300
0.865
, http://www.100md.com 0.925
0.755
1.170
1.250
1.940
1.1185
0.3519
5
0.650
0.880
1.040
1.075
0.865
, http://www.100md.com
0.915
0.920
0.890
1.065
1.105
0.9405
0.1366
6.3
0.685
0.950
1.120
1.285
0.815
, 百拇医药
0.840
0.930
0.900
0.865
0.845
0.9235
0.1686
8
1.040
0.970
0.945
0.950
1.045
, http://www.100md.com
0.950
0.930
0.965
1.180
0.955
0.993
0.07646
10
1.045
1.140
1.175
1.130
1.230
, 百拇医药
1.050
1.300
1.050
1.075
0.725
1.092
0.1541
12.5
1.240
1.255
1.085
1.080
1.055
, http://www.100md.com
1.070
1.110
1.230
1.030
0.815
1.097
0.1292
16
1.215
1.045
1.315
0.810
0.910
, 百拇医药
1.130
1.250
1.360
0.535
0.485
1.0055
0.3130
20
1.640
1.220
1.710
1.300
1.005
, 百拇医药
1.105
1.250
1.410
0.570
0.605
1.1815
0.3808
25
2.190
1.560
2.110
1.410
1.145
, http://www.100md.com
1.685
1.355
0.930
0.550
0.710
1.3645
0.5486
31.5
1.855
1.355
1.935
1.290
1.215
, 百拇医药
1.210
1.220
1.505
0.625
0.955
1.3165
0.3873
40
2.190
1.360
2.000
1.840
1.400
, http://www.100md.com
1.460
1.455
1.645
0.770
0.905
1.5025
0.4451
50
2.460
1.610
2.630
1.475
2.155
, http://www.100md.com
1.395
1.360
1.650
0.705
0.600
1.604
0.6689
63
2.650
1.400
2.155
2.520
1.925
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1.415
1.775
1.675
0.655
1.135
1.7305
0.6157
80
2.490
1.705
2.395
1.955
1.515
, 百拇医药
1.135
1.560
2.150
0.980
0.960
1.6845
0.5589
Compared with ISO 2631-1,the frequency weightings of Chinese young males at 16～80Hz are significantly higher than those of ISO 2631-1(P<0.005),and there are no significant difference between two frequency weighting contours at other frequencies.In other words,Chinese young males are more sensitive to the vibration at 16～80Hz.Discussion
, 百拇医药
The frequency weightings and the vibration sensation are related to the effects of vibration on the human body and transmissibility of the human body.In general,a human body can be regarded as one or more spring-mass system with viscous damping.For a spring-mass system with viscous damping,its equation of motion is:
Where:t—time;
x—the displacement of the system;
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m—the mass of the system;
k—the stiffness of the system;
c—the viscous damping coefficient of the system;
F—the magnitude of force acting on the system;
f—the frequency of the force.
The acceleration resonance frequency of the system is
If the frequency of the force is near to the acceleration resonance frequency of the system,the acceleration of the system is greater and the transmissibility to the system is higher than those when the frequency of the force is far from it.In general,<<1,so the smaller the m the higher the acceleration resonance frequency,and the larger the k the higher the acceleration resonance frequency.For a thin person,m is usually smaller than that of fat one and k usually is larger than that of fat one,and his acceleration resonance frequency will be higher than that of the fat one.Hence,the effects of vibration on a thin person at higher frequencies are more considerable than that on a fat one and the transmissibility of vibration to a thin human body at higher frequencies is higher than that to a fat human body.In fact,for Chinese,there are three acceleration resonance frequencies[4],5.59 Hz,11.24 Hz,26.89 Hz; but for those being similar to those covered in ISO 2631-1,there are only two acceleration resonance frequencies[5],5.78 Hz,and 10.76 Hz.Thus,at higher frequencies far from 10.76 Hz,the effects of vibration on Chinese should be more considerable than that on those covered in ISO 2631-1 and the transmissibility of vibration to their bodies should be higher than that to the bodies of those covered in ISO 2631-1.Because the volunteers in this paper are Chinese young males,they may be thinner and brawnier than those covered in ISO 2631-1 and the effects on them at higher frequencies may be more considerable and the transmissibility of vibration to their bodies at higher frequencies may be higher.Hence,they are more sensitive to the vibration at 16～80 Hz in z axis than those covered in ISO 2631-1., 百拇医药
[References]
[1] International standard ISO 2631-1-Mechanical vibration and shock-Evaluation of human exposure to whole-body vibration-Part 1: General requirements[S].1997
[2] Griffin MJ.Handbook of human vibration[M].London: Academic Press,1990:27～40
[3] Peng Shaoping,LI Yingzhong,Han Yibao et al.A study of equal vibration sensation contours of three waveforms vibration and the preliminary research on the application of the parameters for vibration evaluation[D].Beijing:Institute of Space Medico-Engineering,1999
, 百拇医药
彭绍平,李盈忠,韩宜保等.不同波形振动的等感研究和评价参数的应用探讨[D].[学位论文]北京：航天医学工程研究所，1999
[4] GB/T 16440-1996-Vibration and shock-Mechani-cal driving point impedance of the human body[S].Bejing:Standardization press of China,1996:2～6
中华人民共和国国家标准GB/T 16440-1996—振动与冲击 人体的机械驱动点阻抗[S].北京:中国标准出版社,1996:2～6
[5] International standard ISO 5982—Mechanical vibration and shock-Mechanical driving point impedance of the human body[S].1981
Received date:1999-09-16, 百拇医药