This paper explores the vibration spectra for planetary gear systems by studying a kinematic model of vibration and comparing the model with measurements of two helicopter transmissions made in flight. The model and flight data include systems with both uniformly and nonuniformly spaced planet gears. This model predicts vibration to occur only at frequencies that are integer multiples of the pl...

This study aimed to develop a device to facilitate grinding experiments with microvibration for analyzing the vibration effect on surface finish of ground surfaces. A microvibration device was designed and fabricated. It can be used to provide microvibration to the workpiece vertically and/or horizontally during grinding. The relationship of the driving voltage, vibration displacement, and freq...

The vibration of fungal cultures was evaluated to determine its potential effect on the dispersal of airborne fungal microorganisms suspected of being pathogens. An artificial vibration system, which simulates the actual environmental vibration of fungal structures, was designed and constructed for this purpose. Experiments featured the use of low-frequency vibrations similar to those induced b...

Vibration fixtures, at times, have resonant frequencies that exist in the frequency range needed for conducting vibration tests. These resonant frequencies can cause significant problems when running vibration tests over ranges which include these resonances. A test engineer will attempt to control the shaker system through a feedback accelerometer which controls the level of vibration input in...

Future deployment of wireless sensor networks will ultimately require a self-sustainable local power source for each sensor, and vibration energy harvesting is a promising approach for such applications. A requirement for efficient vibration energy harvesting is to match the device and source frequencies. While techniques to tune the resonance frequency of an energy harvesting device have recen...

Vibration torque are existence obviously during operation of stepping motor, it is a periodic structure vibration problem. In this paper, the actual vibration torque testing of stepper motor is executed through a selfmade vibration torque sensor, the experimental results show that the stepping motor vibration torque of single three shot operation is more bigger than the six shot, and obvious re...

abstract: the main aim of the vibration energy harvesters is to locally power autonomous devices such as wireless sensors. generally, power levels are low and the environmental benefit of the technology is to replace batteries rather than saving energy per se. piezoelectric vibrational energy harvesters are usually inertial mass based devices, where a cantilever beam with a piezoelectric outer ...

This paper proposes a method for determining maturity levels of durian by using nondestructive vibration. The vibration is transferred directly through durian at a region between prickles located at the middle of durian. The measurement of frequency response from vibration of durian is performed by using laser doppler. The signal is processed for finding velocity of vibration, elastic constants...

Vibration is one of the major drawbacks of Linear Switched Reluctance Motor (LSRM). Two design techniques to reduce vibration in the LSRM are proposed. A detailed mathematical approach for calculating natural frequency has been outlined. Different techniques to predict the vibration frequencies are analyzed using ANSYS software. The analyzed structures are compared by using experimental and sim...

This paper investigates the bending vibration of rotating single-walled carbon nanotubes (SWCNTs) based on nonlocal theory. To this end, the rotating SWCNTs system modeled as a beam with a circular cross section and the Euler-Bernoulli beam theory (EBT) is applied with added effects such as rotary inertia, gyroscopic effect and rotor mass unbalance. Using nonlocal theory, two coupled sixth orde...