Modeling, Simulation & Analysis of Whole Body Vibration for Two Wheeler 2013-01-2859

Whole body vibration deals with the biodynamic responses of human body in various postures. Vertical vibration exposure in sitting posture is common situation encountered while driving vehicle or riding motorcycle. We have chosen Wan & Schimmel's 4 DOF biodynamic model for this study by referring the goodness of fit results for various models available in the literature. A single degree of freedom model of motorcycle is used for analysis of whole body vibration on two wheeler. We have neglected pitch, yaw movements of two wheeler for purpose of simplicity.

Whole body vibration analysis for human body in sitting posture is described by three terms i.e. Seat to Head Transmissibility (STH), Driving point impendence (DPM) & apparent mass (AP). In order to analyze human response on motorcycle Road to head (RTH), Road to lower torso (RTLT), Road to viscera (RTV), Road to upper torso (RTUT) responses are calculated for different motorcycle suspension natural frequencies. Simulation of biodynamic model is carried in MATLAB which shows close match with experimental results from literature. Analysis shows that peak values occur at 3.97 Hz, 6.77 Hz & 3.24 Hz for STH, DPM & AP respectively. For 4 Hz suspension natural frequency of motorcycle, most severe RTH, RTUT, RTV, RTLT responses are noted. These responses are severe in the two wheeler suspension natural frequency range of 3.5 Hz to 5.5 Hz. This study will help in better design & also in improving the ride & handling performance of two wheeler.