whole body vibration can deteriorate health bringing about or back pain or spinal column injury, resulted from continuing exposure to vibration. also exposure to vibration can cause disorder in central nervous system and adversely influence vascular and skeletal systems. in this research, the vibration of universal 650m tractor seat and its effect on the operator in five levels of engine speeds...

TORVINEN, S., P. KANNUS, H. SIEVÄNEN, T. A. JÄRVINEN, M. PASANEN, S. KONTULAINEN, T. L. JÄRVINEN, M. JÄRVINEN, P. OJA, and I. VUORI. Effect of four-month vertical whole body vibration on performance and balance. Med. Sci. Sports Exerc., Vol. 34, No. 9, pp. 1523–1528, 2002. Purpose: This randomized controlled study was designed to investigate the effects of a 4-month whole body vibration-interve...

this research concentrates on the effects of low frequency, vertical mechanical vibration during solidification on the microstructure and mechanical properties of a380 aluminum alloy. two series of sr-modified and al-5ti-b grain refined a380 alloy samples were solidified in both static and dynamic conditions in the frequency and amplitude of 60 hz and 0.2 m, respectively. their physical, micro-...

The biodynamic responses to the human body give an understanding of why human responses to vibration (changes in health, comfort, and performance) vary with the frequency and direction of vibration. Studies have shown that biodynamic responses also vary with the magnitude of vibration and that the backrests of seats influence the transmission of vibration to the seated human body. There has bee...

The resulting motion in waves can be considered as a superposition of the motion of the body in still water and the forces on the restrained body. In this study the effect of added mass fluctuation on vertical vibration of TLP in the case of vibration in still water for both free and forced vibration subjected to axial load at the top of the leg is presented. This effect is more important when ...

Models of the vertical apparent mass of the human body are mostly restricted to a sitting posture unsupported by a backrest and ignore the variations in apparent mass associated with changes in posture and changes in the magnitude of vibration. Using findings from experimental research, this study fitted a single degree-of-freedom lumped parameter model to the measured vertical apparent mass of...

Centrifugal compressors produce high pressure ratio and rotate at speeds. So, a tiny unbalance can produce severe vibration. In this paper, effects of impeller gap on rotor vibration in a high speed centrifugal compressor is investigated. For this purpose, a numerical and experimental analysis are carried out. The moving reference frame method in FLUENT software is used for modeling of geometri...

Piping vibration which is mainly caused by the torsional vibration of rotary compressor can be a major noise source of air-conditioner. Especially, the tangential vibration of rotary compressor which is due to the torsional vibration is much higher than the radial vibration or the vertical vibration of compressor. A study as to how the tangential vibration of rotary compressor is related with t...

This paper presents the results of laboratory experiment concerned with perception thresholds for whole-body vibration on recumbent subjects. Thresholds of subjects exposed to x-, yand z-axis sinusoidal vibration were determined for supine, prone, lying on the left side and lying on the right side subjects (from 1 to 80 Hz). It was clear that the threshold curves, as a function of frequency, ha...