Analysis of bus users' vibration exposure time

Abstract The paper analyzes the effects of vibrations on allowable vibration exposure time in intercity bus users for the criterion of reduced comfort according to the ISO 2631/1985 standard. The analysis was carried out using a validated spatial oscillatory model of 65 degrees of freedom (DOF) built in the ADAMS/View module of the MSC.ADAMS package. Simulation results revealed that passengers on the bus front and rear overhang have very short allowed exposure time. In order to extend the exposure time, by using Design of Experiments (DOE) analysis, new oscillatory parameters for passengers' seats are proposed. With new oscillatory parameters, the exposure time is significantly extended for the assistant driver and passengers on the front and rear bus overhang. For the passenger on the last row seat, power spectral density of weighted vertical acceleration is of lower intensities even at frequencies above 4 Hz. Relevance to industry: Bus users (passengers and drivers) are exposed to harmful effects of vibrations. Vibrations influence comfort, work ability, and if increasingly intense can affect human health. Allowable vibration exposure time referring to oscillatory comfort has a particular importance for intercity bus' passengers when traveling longer distances. Vibration time could be extended by proper selection of seat oscillatory parameters. Results of such an analysis can significantly help bus manufacturers and designers in order to improve ride comfort for bus' passengers.