An investigation of noise in a micro stepping motor is considered to study in this article. Because of the trend towards higher precision and more and more small 3C (including Computer, Communication and Consumer Electronics) products, the micro stepping motor is frequently used to drive the micro system or the other 3C products. Unfortunately, noise in a micro stepped motor is too large to acc...

In this study, ambient and forced vibration tests are proposed to evaluate dynamic characteristics of a caisson-type breakwater including natural frequencies and modal damping ratios, and the feasibility of numerical analysis model with fluid-structure-soil interaction effects, which plays an important role to evaluate structural performance and safety, is investigated by comparing the numerica...

This study demonstrates a method for harvesting the electrical power by the piezoelectric actuator from vibration energy. This paper presents the energy harvesting technique using the piezoelectric element of a bimorph type driven by a geared motor and a vibrator. The geared motor is a type of PWM controlled device that is a combination of an oval shape cam with five gears and a speed controlle...

In order to measure the nonlinear features of micromechanical resonators, a free damped oscillation method based on stair-stepped frequency sinusoidal pulse excitation is investigated. In the vicinity of the resonant frequency, a frequency stepping sinusoidal pulse sequence is employed as the excitation signal. A set of free vibration response signals, containing different degrees of nonlinear ...

This study presents a precision stage driven by a piezoelectric actuator and equipped with a displacement magnification mechanism for the purpose of easy displacement measurement. The displacement magnification mechanism consists of flexible hinges and lever mechanisms. The developed stage is able to provide accurate measurement by virtue of the displacement magnification mechanism, but it is e...

(P being the pulsation period) could, therefore, assume any value. Moreover, if the disturbing force were periodic, a resonance of the free and forced periods would be immediately established and the amplitude of the oscillation greatly enhanced. Second-order effects, ignored in the present investigation, would thus probably soon become appreciable and could operate to destroy the resonance. Sh...

In the present work, FGM shells integrated with magnetostrictive layers acting as distributed sensors and actuators are modeled to control vibration attenuation of FGM shells with simply supported boundaryconditions. To achieve a mechanism for actively control of the oscillation amplitude of the integrated structure, a negative velocity proportional feedback control law is implemented in the st...

In this paper, nonlinear vibration analysis of functionally graded piezoelectric (FGP) beam with porosities material is investigated based on the Timoshenko beam theory. Material properties of FG porous beam are described according to the rule of mixture which modified to approximate material properties with porosity phases. The Ritz method is used to obtain the governing equation which is then...

This article presents an analysis of free vibration of elastically supported Timoshenko beams by using the spectral element method. The governing partial differential equation is elaborated to formulate the spectral stiffness matrix. Effectively, the non classical end boundary conditions of the beam are the primordial task to calibrate the phenomenon of the Timoshenko beam-soil foundation inter...