AN EXPERIMENTAL AND COMPUTATIONAL STUDY OF SEATED POSTURE OF HUMAN UNDER LOW FREQUENCY VIBRATIONS

Abstract

Present days of busy life people are using two wheelers, cars, busses and trains for travelling to other places or officers etc. In daily travelling people are exposed under vibration always. And some people are working in mines also exposed to vibration causes many health effects and diseases such as acute or chronic type. In the present work, the types of posture and effect of posture positions, effect of vibration in different direction has been studied along-with the factors to reduce the vibration and standards, which are used for whole body vibration. The work also describes the factors affecting the vibration discomfort such as extrinsic and intrinsic variables. In intrinsic variables mainly inter and intra subject variability discussed. In the experimental study, the erect and 30° inclined backrest postures are used. Experiments have been conducted on total 6 male persons between frequency range from 3- 12 Hz, and three vibration magnitudes (0.4, 0.8, 1.2 m/sec2 R.M.S.). Effect of inter subject variability has been observed from the graphs and also effect of magnitude on different posture also observed. The 5-DOF model is prepared and Bio dynamic parameters such as Transmissibility and DPMI has also been calculated through formulas and represented in the graphs. The model results are compared with the experimental study observed the resonance frequency 5 Hz. in both the study.