A study of the free vibration of Timoshenko beams and axisymmetric Mindlin plates is presented. The analysis is based on the Chebyshev pseudospectral method, which has been widely used in the solution of fluid mechanics problems. Clamped, simply supported, free and sliding boundary conditions of Timoshenko beams are treated, and numerical results are presented for different thickness-to-length ...

This paper presents the elastic buckling of homogeneous beams with a pair of piezoelectric layers surface bonded on both sides of the beams. The displacement field of beam is assumed based on the Engesser-Timoshenko beam theory. Applying the Hamilton's principle, the equilibrium equation is established. The influences of applied voltage, dimensionless geometrical parameter and piezoelectric thi...

in this paper, surface and piezoelectric effects on the vibration behavior of nanowires (nws) are investigated by using a timoshenko beam model. the electric field equations and the governing equations of motion for the piezoelectric nws are derived with the consideration of surface effects. by the exact solution of the governing equations, an expression for the natural frequencies of nws with ...

most of the methods that have been proposed for speed estimation of induction machines require the rotor and the stator resistance to change in the normal operating range. on the other hand, estimation of the rotor resistance requires rotor speed. in this paper, after studying conditions for simultaneous estimation of rotor speed and rotor resistance, a method for simultaneous estimation of rot...

the rotor of enegelberg whitener was equipped with a screw conveyor to reduce broken rice percentage. according to preliminary experiments this modification could reduce broken rice percentage about 2.5%. further experiment was performed to determine the effect of rotor speeds and blade positions on white rice quality. to do this, five rotor speeds, consisting 500, 600, 700, 800 and 900 r.p.m a...

tip leakage loss introduces major part of losses of the rotor in axial gas turbines. therefore, the rotor blade tip has a considerable effect on rotor efficiency. to understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). various blade tip configurations such ...

in this research, the steady-state flow filed around a 3d body and rotor configuration of the robin helicopter is simulated. the rotor is modeled by an actuator disk. for this purpose, an annular computational domain replaces the rotor and some modeled source terms are added to the momentum equations. this modeling of rotor considerably speed up computational time. the flow field over this heli...

in this research work with the aid of tagouchi experimental design and rawing of interaction curves with minitab software, the best rotor speed and dump temperature of mixing for physico-mechanical and rheological properties of the rubber compound with three mixing steps was obtained. moreover by plotting the mean curves in excel worksheet, the dependency of properties on rotor speed, dump temp...