A new vibration isolation system is proposed which uses zero-power magnetic suspension. Since a zero-power system behaves as if it has a negative stiffness, combining it with a normal spring can generate infinite stiffness against disturbances on the isolation table. It enables the system to have good performance both in reducing vibration transmitted from ground and in suppressing direct vibra...

Humans can discriminate among the hardness of objects by tapping their surfaces. The damped natural vibration caused by tapping and its frequency are known to be the cue for the perception of hardness. This study is an investigation of the characteristics of this perception of hardness, as induced by vibration stimuli including multiple frequency components. We performed a comparative experimen...

A vibration isolation module with zero-power magnetic suspension is developed to retrofit a passive vibration isolation system to improve the performance against direct disturbance. In the module, the zero-power magnetic suspension mechanism is connected in series with a normal spring through a middle mass. This structure can generate zero compliance to direct disturbance while the transmitted ...

Based on the development of numerical analysis techniques over the past decade, the engineer can easily model the internal flow conditions and vibration characteristics of turbomachinery. When focusing on vibration response of rotating blades, it is easy to predict the resonance frequency; however difficulty remains in the prediction of vibrational stress. The primary reasons include: The unste...

Non-contact testing is an important method for the study of the vibrating characteristic of cylindrical resonators. For the vibratory cylinder gyroscope excited by piezo-electric electrodes, mode testing of the cylindrical resonator is difficult. In this paper, a novel vibration testing method for cylindrical resonators is proposed. This method uses a MEMS microphone, which has the characterist...

To process the vibration signal fault diagnosis automatically and effectively, a method to calculate the generalized fractal dimension (Dq) based on the traditional G-P correlation dimension algorithm is presented. First, the vibration signal, a kind of random fractal that meets the statistical self-similarity, is reconstructed according to the phase space reconstruction theory. Second, for var...

OBJECTIVES Transportation of goods on railways is increasing and the majority of the increased numbers of freight trains run during the night. Transportation noise has adverse effects on sleep structure, affects the heart rate (HR) during sleep and may be linked to cardiovascular disease. Freight trains also generate vibration and little is known regarding the impact of vibration on human sleep...

Shell structures, especially cylindrical shells, are widely used in aerospace and naval architectural industries. Submarine hulls and aircraft bodies can be idealized as cylindrical shell structures. The study of vibrations of cylindrical shells is an important aspect in the successful applications of the cylindrical shells. The free vibration characteristics of a submarine hull have an importa...

In this study, nonlinear vibration of axially moving strings in thermal environment is investigated. The vibration haracteristics of the system such as natural frequencies, time domain response and stability states are studied at different temperatures. The velocity of the axial movement is assumed to be constant with minor harmonic variations. It is presumed that the system and the environment...

Abstract: According to the chaotic features and typical fractional order characteristics of the bearing vibration intensity time series, a forecasting approach based on long range dependence (LRD) is proposed. In order to reveal the internal chaotic properties, vibration intensity time series are reconstructed based on chaos theory in phase-space, the delay time is computed with C-C method and ...