Development of Biodynamic Models for a Seated Human Body Subjected to Harmonic Vibrations

Abstract

Humans are most sensitive to Whole Body Vibrations (WBV) under low-frequency excitation. As a result, biodynamic responses of seated human subjects when exposed to vibrations have been a topic of interest over the years. Knowledge of the biodynamic responses is required for designing, analysis and testing of transport vehicles with an aim to improve passenger and driver comfort. In the present research work biodynamic models based on anthropometric data of Indian male subjects have been obtained. For this study, seated human subjects in different postures: without backrest and with backrest (inclined at 0˚, 15˚ and 30˚ to the vertical) for rigid as well as cushioned seats have been considered. STHT values have been evaluated and the effect of different vibration magnitudes and excitation frequencies on it has been obtained. Experimental investigations have been conducted on twelve subjects for all the above cases and mean STHT values were determined. Validation of analytically obtained STHT values and experimentally determined ones has been attempted. In order to assess the transmission of vibrations through different human body segments, common subjective response studies were also conducted on human subjects for all the cases mentioned above and their common responses were obtained and discussed.