rasoul shabani
mechanical engineering, Urmia university
[ 1 ] - Stabilization of Electrostatically Actuated Micro-pipe Conveying Fluid Using Parametric Excitation
This paper investigates the parametric excitation of a micro-pipe conveying fluid suspended between two symmetric electrodes. Electrostatically actuated micro-pipes may become unstable when the exciting voltage is greater than the pull-in value. It is demonstrated that the parametric excitation of a micro-pipe by periodic (ac) voltages may have a stabilizing effect and permit an increase of the...
[ 2 ] - A Numerical Improvement in Analyzing the Dynamic Characteristics of an Electrostatically Actuated Micro-beam in Fluid Loading with Free Boundary Approach
Electrostatically actuated microbeams have been studied by many researchers in the last few years. The aim of this study is to present an improved numerical analysis of the dynamic instability of a cantilever microbeam immersed in an incompressible viscous fluid. The finite element method is used for solving the vibrational equation of the microbeam and the potential functions of the fluids in ...
[ 3 ] - Vibration Analysis of an Air Compressor Based on a Hypocycloidal Mechanism: an Experimental Study
In this paper, the experimental vibration analysis of a single cylinder air compressor based on a hypocycloid straight line mechanism (HSM) is investigated. The HSM mechanism uses planetary gears to convert rotational motion to purely linear motion. In the conventional air compressor, the slider- crank mechanism is replaced by the HSM mechanism with appropriate counterweights. The constructed s...
[ 4 ] - Investigation of Thermoelastic Damping in the Longitudinal Vibration of a Micro Beam
In the design of high Quality factor (Q) micro or nano beam resonators, different dissipation mechanisms may have damaging effects on the quality factor. One of the major dissipation mechanisms is the thermoelastic damping (TED) that needs an accurate consideration for prediction. In this paper, thermoelastic damping of the longitudinal vibration of a homogeneous micro beam with both ends clamp...
[ 5 ] - Introducing Padded Wall to Reduce Sloshing Induced Wall Pressure in Water Storage Tanks
Sloshing due to ground motion develops large pressure on the walls of water retaining tanks. This paper evaluates the efficacy of padded walls on the reduction of sloshing effects in rectangular water storage tanks subjected to ground motion. An analytical solution based on velocity potential function is provided to obtain the response of rigid and padded wall tanks in terms of the wave elevat...
[ 6 ] - Tracking and Shape Control of a Micro-cantilever using Electrostatic Actuation
In this paper the problems of state estimation, tracking control and shape control in a micro-cantilever beam with nonlinear electrostatic actuation are investigated. The system’s partial differential equation of motion is converted into a set of ordinary differential equations by projection method. Observabillity of the system is proven and a state estimation system is designed using extended ...
[ 7 ] - Hydroelastic Vibration of a Circular Diaphragm in the Fluid Chamber of a Reciprocating Micro Pump
Reciprocating diaphragm micro-pumps are the most common type among indirectly–driven micro-pumps. They operate by reciprocating the diaphragm with associated check valves. This paper addresses the Hydroelastic vibration of circular elastic diaphragm interacting with the incompressible and inviscid liquid inside the cylindrical chamber with a central discharge opening. Taking into account axisym...
[ 8 ] - Stability Analysis in Parametrically Excited Electrostatic Torsional Micro-actuators
This paper addresses the static and dynamic stabilities of a parametrically excited torsional micro-actuator. The system is composed of a rectangular micro-mirror symmetrically suspended between two electrodes and acted upon by a steady (dc ) while simultaneously superimposed to an (ac ) voltage. First, the stability of the system subjected to a quasi-statically applied (dc ) voltage is investi...
[ 9 ] - Stress Patterns in Single Deck Floating Roofs Subjected to Ground Motion Accelerations
This paper investigates the induced stresses in circular single deck roofs floating on seismically excited storage tanks. Equations of motion are derived using variational principle. Response of deck floating roofs is evaluated for two different classes of ground motions; near-source and long-period far-field records. Besides time histories and frequency contents for a specific tank, peak value...
[ 10 ] - Thermo-Elastic Damping in Nano-beam Resonators Based on Nonlocal Theory
In this article thermoelastic damping in nano-beam resonators is investigated based on nonlocal theory of elasticity and the Euler-Bernoulli beam assumptions. The governing equation of deflection of the beam is obtained from shear and moment resultants and stress–strain relationship of the nonlocal elasticity model and also the governing equations of thermoelastic damping are established by usi...
[ 11 ] - Mechanical Response of a Piezoelectrically Sandwiched Nano-Beam Based on the Non-Local Theory
This article deals with the mechanical analysis of a fixed-fixed nano-beam based on nonlocal elasticity theory. The nano-beam is sandwiched with two piezoelectric layers through it’s upper and lower sides. The electromechanical coupled equations governing the problem are derived based nonlocal theory considering to Euler-Bernoulli beam assumptions and based on the nonlocal piezoelectricity acco...
[ 12 ] - STATIC AND DYNAMIC RESPONSE OF CARBON NANOTUBE-BASED NANOTWEEZERS
In this paper static and dynamic response of nanotweezers composed of two carbon nanotube (CNT) arms are investigated. Taking into account a continuum model and considering the electrostatic actuation as well as the presence of the van der Waals forces, the static nonlinear equations are solved by a step by step linearization and Galerkin projection method. Simulating the closing dynamics of a ...
[ 13 ] - Effect of Flexural and Membrane Stiffness on the Analysis of Floating Roofs
With the aim of extending the use of integrated variational principles on fluid and deckplate to the large deflection analysis of floating roofs, this paper investigates the significance of theflexural and membrane components in the formulations of the deck plate. Applying integratedvariational principles on deck plate and fluid facilitate the treatment of the compatibility ofdeformation betwee...
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