Title: A contribution to identification of a non-linear biodynamic oscillatory model of man

Authors: Miroslav Demic

Addresses: Faculty of Mechanical Engineering, 34000 Kragujevac, Yugoslavia.

Abstract: In optimizing oscillatory parameters of motor vehicles, there is a need to use biodynamic oscillatory models of the human body, since all the oscillatory excitations that a person is exposed to in a vehicle are most often random, and sometimes shock or harmonic, use of many well-known models (described in various reports in the literature) would not give acceptable results in all characteristic cases. Therefore, based on data obtained from tests on input mechanical impedance of man in a passive sitting position, this paper has made an attempt to identify a non-linear biodynamic oscillatory model of man namely, a man is approximated by three concentric masses, mutually connected by non-linear and linear damping elements. Using an electronic computer the following parameters were identified: m₁ = 42 kg; m₂ = 23 kg; m₃ = 5 kg; C₀₁ = 14000 daN/m; C₀₂ = 500 daN/m³; K₀₁ = 360 daNs/m; C₁₁ = 16000 daN/m; C₁₂ = 400 daN/m³; K₁₂ = 270 daNs/m; C₂₁ = 17000 daN/m; C₂₂ = 900 daN/m³; K₂₁ = 285 daNs/m. These parameters enable a very good simulation to be made of human body behaviour under influence of random shock and harmonic excitation. The paper also indicates that it is better to use simple non-linear models than complex linear biodynamic oscillatory models in optimizing characteristics of motor vehicles.

Keywords: biodynamics; oscillatory models; ride comfort; human response; vehicle vibration; linear modelling; nonlinear modelling; oscillatory behaviour; simulation; random shocks; harmonic excitation; vehicle design.

DOI: 10.1504/IJVD.1989.061618

International Journal of Vehicle Design, 1989 Vol.10 No.2, pp.153 - 164

Published online: 26 May 2014 *

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