Free vibration of soil often occurs during earthquakes. Since the vibration caused by earthquake does not have (steady state harmonic vibration) continuity, the alluvium vibrates with its natural frequency between two natural seismic waves. This study evaluates the effect of piles on the period of free vibration of a soil layer using numerical method. In the first stage, using analytical equati...

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 temporary threshold shift of temperature sensation due to vibration exposure was studied to clarify the significance of frequency and acceleration on it. The discrete frequencies of the vibrations tested were 32, 63, 125, 250 and 500 Hz, and the accelerations were at the level of 2, 4, 8 and 16 g. The threshold shift of warm sensation (TTSw) was markedly, but that of cool sensation was smal...

In running cars or trains, passengers often feel sleepy. Our study focuses on this physiological phenomenon. If a machine can reproduce this phenomenon, it is feasible to put a person, such as an insomnia patient or an infant, to sleep without any harmful effects. The results of our previous study suggest that low-frequency vibration induces sleep. This report describes a new mechanical bed for...

Drivers of mining trucks are exposed to whole-body vibrations (WBV) and shocks during the various working cycles. These exposures have an adversely influence on the health, c...

natural vibration analysis of plates represents an important issue in engineering applications. in this paper, a new and simplify method for vibration analysis of circular and rectangular plates is presented. the design of an effective robust controller, which consistently attenuates transverse vibration of the plate caused by an external disturbance force, is given. the dynamics of the plate i...

dans cet article i' intervalle entre deux trains successifs a ete etudie en fonction de leur vitesses dans deux cas differents. dans ie premier cas ,on suppose que la vitesse des deux trains a une valeur constante, et on etudie les variations de l'intervalle minimum en fonction de la vitesse on determine la vitesse optimale et on etudie les variations de l'intervalle minimum en f...

building caused by floor impact sound. In this study, the concrete slab measured vibration impact sound for evaluation floor vibration of deteriorated buildings that fails to satisfy with the minimum thickness. In this experimental study, the vibration scale by impact sound was calibrated and compared with ISO and AIJ standard for vibration. The results show that vibration in slab with thicknes...