When material is subjected to an intense load its stiffness changes due to elastic nonlinearity. This effect is especially pronounced in damaged materials so that nonlinearity can be used as an indication of incipient damage. Under dynamic load, mechanical constraint between the fragments of planar defects provides gigantic nonlinearity in finite-amplitude contact vibrations. The local vibratio...

BACKGROUND Accelerometry (the measurement of vibrations) and auscultation (the measurement of sounds) are both non-invasive techniques that have been explored for their potential to detect abnormalities in swallowing. The differences between these techniques and the information they capture about swallowing have not previously been explored in a direct comparison. METHODS In this study, we in...

Due to the increasing share of new renewable energies like wind and solar in the generation of electricity the need for power regulation and energy storage is becoming of paramount importance. One of the systems to store huge amounts of energy is pumped storage using reversible hydropower units. The machines used in these power plants are pump-turbines, which can operate as a pump and as a turb...

vibration generated by vehicles during road transport has an important effect on the agricultural products damage process, particularly vegetable and fruit. modulus of elasticity is one of the most important mechanical properties of fruits and its variation can be described as one of the damage criteria during transportation. this research was conducted to evaluate the effects of vibration para...

in this study, the mf285 tractor engine vibrations resulting from the use of different combinations of biodiesel, bioethanol and diesel as fuel were studied. engine vibrations in three directions and three engine speeds: 1000, 1600 rpm 2000 and ten fuel level was measured. to investigate the influence of measured parameters on engine vibration of factorial design in a randomized complete block ...

In this paper, we present a novel technique to estimate the position of the rotor of a switched reluctance motor by observing the characteristics of the vibration of the stator during the motor operation. This removes the need of the shaft position sensor which is known for its unreliability and problems associated with its application. Vibration in switched reluctance motors is generated mainl...

An accurate method of estimating the efficiency of in-service motors is needed in order to determine the performance of installed motors without disrupting the motor driven process.. In this paper, the motor efficiency is estimated using a non-intrusive implementation of the compensated slip method. The motor speed is accurately estimated using motor vibration signature analysis. A few other ef...

This paper presents a mathematical model to investigate the nonlinear dynamic behavior of a high speed rotor-bearing system due to defects of rolling elements. Two defects have been considered for the study, one defect as off-sized rolling elements and other defect as rolling element waviness. In the formulation, the contacts between rolling elements and inner/outer races are considered as nonl...

Due to growth of mechanisation and automation, today’s industrial systems are becoming more complex. A small breakdown of any non-redundant machine component affects the operation of the entire system. To increase the availability and reliability, automated health monitoring and self-diagnostic capability (SDC) becoming essential to many industrial machineries like pumps, motors, etc. Condition...

A mathematical model of a cracked rotor and an asymmetric rotor with two disks representing a turbine and a generator is uti­ lized to study the vibrations due to imbalance and side load. Nonlinearities typically related with a “breathing” crack are included using a Mayes steering function. Numerical simulations demonstrate how the variations of rotor parameters affect the vibration response an...