in this paper, a numerical solution procedure is presented for the forced vibration of a piezoelectric nanowire under thermo-electro-mechanical loads based on the nonlocal elasticity theory within the framework of timoshenko beam theory. using hamilton’s principle, the nonlocal governing differential equations are derived. the governing equations and the related boundary conditions are discreti...

This paper presents a finite element formulation for the dynamics analysis of the steady and transient states of a nonlinear piezoelectric beam. A piezoelectric beam with damping is studied under harmonic excitation. A numerical method is used for this analysis. In the paper, the central difference formula of four order is used and compared with the central difference formula of two order in th...

energy harvesting from surrounding environment has been attractive for many researchers in recent years. therefore, developing appropriate test apparatus to study energy harvesting mechanisms and their performance is of paramount importance. due to their electromechanical characteristics, piezoelectric materials are used for harvesting energy from environmental vibrations. for optimum utilizati...

In this paper, we present mathematical analyses to consider the effect of material properties on the sensitivity of the Microelectromechanical systems (MEMS) piezoelectric hydrophone and improve the sensitivity by choosing the proper material. The selected structure in the present paper is a piezoelectric hydrophone able to work at low frequencies. The piezoelectric hydrophones are widely used ...

The super-knock poses new challenges for further increasing the power density of spark ignition (SI) engines. critical factors and mechanism connecting regarding occurrence are still unclear. Misfire is a common phenomenon in SI engines that mixture cylinder not ignited normally, which often caused by plug failure. However, effect misfire on engine combustion has been paid enough attention to, ...

piezoelectric nanobeams having circular, rectangular and hexagonal cross-sections are synthesized and used in various nano structures; however, piezoelectric nanobeams with hexagonal cross-sections have not been studied in detail. in particular, the physical mechanisms of the surface effect and the role of surface stress, surface elasticity and surface piezoelectricity have not been discussed t...

the effective factors of forward speed, cylinder rotation, and clearance between a combine’s cylinder and concave on wheat kernel breakage and seed germination were studied in karaj area using a 955 model john dear combine. this study was conducted on three levels of adjustment for each of the variables, 1.2, 1.8 and 2.5 km/hr for forward speed, 800, 900, 1000 rpm for cylinder rotation as well ...

In this study, a modified disk-shaped multiple-output piezoelectric transformer operated at the fundamental radial vibration mode has been presented. A derived equivalent circuit for the multioutput piezoelectric transformer was used to analyze the performance. Two piezoelectric transformers, a symmetrically electroded piezoelectric transformer with dual outputs and an asymmetrically electroded...

in this paper the active vibration control of a four-story shear frame instrumented with piezoelectric actuators is presented. the piezoelectric actuators are hosted on the columns in two manners and the produced controlling forces by actuators are considered in the equation of motion. the smart structure modeling and control design is carried out using matlab software in state space form. subs...