title: Analysis of non-linear response of the human body to vertical whole-body vibration.
abstract: The human response to vibration is typically studied using linear estimators of the frequency response function, although different literature works evidenced the presence of non-linear effects in whole-body vibration response. This paper analyses the apparent mass of standing subjects using the conditioned response techniques in order to understand the causes of the non-linear behaviour. The conditioned apparent masses were derived considering models of increasing complexity. The multiple coherence function was used as a figure of merit for the comparison between the linear and the non-linear models. The apparent mass of eight male subjects was studied in six configurations (combinations of three vibration magnitudes and two postures). The contribution of the non-linear terms was negligible and was endorsed to the change of modal parameters during the test. Since the effect of the inter-subject variability was larger than that due to the increase in vibration magnitude, the biodynamic response should be more meaningfully modelled using a linear estimator with uncertainty rather than looking for a non-linear modelling.
authors.affiliation: a Department of Mechanical Engineering , Politecnico di Milano , Lecco , Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Tarabini
authors.forename: Stefano
authors.initials: S
authors.lastname: Solbiati
authors.forename: Giovanni
authors.initials: G
authors.lastname: Moschioni
authors.forename: Bortolino
authors.initials: B
authors.lastname: Saggin
authors.forename: Diego
authors.initials: D
authors.lastname: Scaccabarozzi
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D008297:Male; D008954:Models, Biological; D011187:Posture; D014732:Vibration / Q000009:adverse effects; D055815:Young Adult
keywords: acceleration exposures; apparent mass; modelling physical response; non-linearity; whole-body vibration