ISO 5982:2001 pdf download

ISO 5982:2001 pdf download.Mechanical vibration and shock – Range of idealized values to characterize seated-body biodynamic response under vertical vibration.
4 Driving-point mechanical impedance and apparent mass of the seated body under vertical vibration
4.1 Definition of values of driving-point mechanical impedance and apparent mass
The modulus and phase of the driving-point mechanical impedance and apparent mass of the seated body are given in Tables 1 and 2 respectively and (for illustration) in Figures 1 and 2 as a function of frequency, for the vertical direction of excitation. In accordance to the definitions, the modulus is given in terms of newton seconds per metre for impedance and kilograms for apparent mass. Each table and diagram contains three values of modulus and phase at each frequency. Numerical values are quoted up to four significant figures for the purpose of calculation, and do not reflect the precision of knowledge of the driving-point mechanical impedance and apparent mass. Linear interpolation is permitted to obtain values at frequencies other than those listed in Tables 1 and 2 at one-third-octave band centre frequencies.
The upper and lower limiting values at each one-third-octave band centre frequency encompass the mean values of all data sets selected, and are shown by bold continuous curves in Figures 1 and 2. The central value at each frequency, shown by fine solid curves in Figures 1 and 2, provides an estimate of the weighted mean of all data sets selected, and forms the target value for all applications. The standard deviations computed with respect to the weighted mean (target) values are also listed in Tables 1 and 2.
Applications that generate/employ values of driving-point mechanical impedance and apparent mass between the upper and lower limits given in Tables 1 and 2 at any frequency satisfy the requirements of this International Standard, and represent “to the body” transfer functions applicable to the seated human body under the conditions specified and over the frequency range of 0,5 Hz to 20 Hz.
If an application only satisfies the requirements of this International Standard at certain frequencies, then those frequencies should be stated in any description of the application.
NOTE 1 The curves in Figures 1 and 2 are derived from the data identified in annex A for driving-point mechanical impedance and apparent mass. The synthesis is performed by transforming all data to the driving-point mechanical impedance function and averaging by weighting the data according to the population of subjects involved in deriving the data. Upper and lower limiting values represent maximum and minimum values of the data sets determined at each frequency. The resulting range of idealized driving-point mechanical impedance values is further transformed to derive the corresponding range of idealized apparent mass values.
NOTE 2 The curves in Figures 1 and 2 relate to 101 test subjects within the mass range 49 kg to 93 kg. Both sinusoidal and broad-band random vibration with unweighted root-mean-square acceleration between 0,5 m/s2 and 3 rn/s2 and frequency- weighted root-mean-square acceleration less than or equal to 2 m/s2 have been used in deriving the data. Some evidence suggests that non-linearities in driving-point mechanical impedance and apparent mass responses may arise with variations in vibration amplitudes, particularly when lower vibration magnitudes are involved.
4.2 Applicability of values of driving-point mechanical impedance and apparent mass
The values of driving-point mechanical impedance and apparent mass are applicable to the seated human body, subjected to sinusoidal or broad-band random vertical vibration, while seated on a rigid surface with the feet resting flat on the base platform and the back being unsupported. The limits of applicability approximately correspond to the range of measurement conditions over which data were obtained, as follows:
a) the posture is described as erect seated without backrest support, while the feet are supported and vibrated;
b) the mass of the subjects ranges from 49 kg to 93 kg;
C) the r.m.s. amplitude of unweighted sine and random excitation is between 0,5 m/s2 and 3,0 m/s2 with predominance of frequencies within the range from 0,5 Hz to 20 Hz. Frequency-weighted r.m.s. amplitudes less than or equal to 2 m/s2 were also part of the vibration excitations considered.