A semi-analytical method is used to illustrate the behavior of a multimodal nonlinear electromechanical system which is under base-excitation. System is considered as piezo-ceramic patches attached to a cantilever beam coupled to a resistive load. The cantilever beam is modeled as a nonlinear Timoshenko beam using Assumed Mode method and equations of motion are derived through Lagrange's equati...

One of the most promising materials in nanotechnology such as sensors, actuators and resonators is annular Boron Nitride sheets (ABNSs) due to excelled electro-thermo-mechanical properties. In this study, however, differential quadrature method (DQM) and nonlocal piezoelasticity theory are used to investigate the nonlinear vibration response of embedded single-layered annular Boron Nitride shee...

This paper aims at investigating the nonlinear behavior of a system which is consisting of two free-free beams which are connected by a nonlinear joint. The nonlinear system is modelled as an in-extensional beam with Timoshenko beam theory. In addition, large amplitude vibration assumption is taken into account in order to obtain exact results. The nonlinear assumption in the system necessities...

Conventional frequency response estimation methods such as the "H1" and "H2" methods often yield measured frequency response functions which are contaminated by the presence of nonlinearities and hence make it difficult to extract underlying linear system properties. To overcome this deficiency, a new spectral approach for identifying multi-degree-of-freedom nonlinear systems excited by Gaussia...

In this paper, the effect of the crack on dynamic behavior of cracked micro-beam in the presence of DC and AC loads are investigated. By applying the residual axial stress and fringing field stress, a nonlinear analytical model of cracked micro-beam is presented and crack is modeled by a massless rotational spring. The governing equation of the system is solved using Galerkin procedure and shoo...

abstract  background: the brain response to temporal frequencies (tf) has been already reported, but with no study reported for different tf with respect to various spatial frequencies (sf).  materials and methods: fmri was performed by 1.5t ge-system in 14 volunteers during checkerboard, with tfs of 4, 6, 8 and 10hz in low and high sfs of 0.5 and 8cpd.  results: average percentage bold signal ...

This article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. The electrostatic actuation was induced by applying AC-DC voltage between the microbeam and electrode plate. In contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. In additio...

The nonlinear frequency response analysis (NFRA) can be seen as an extension of electrochemical impedance spectroscopy. NFRA gives a full and detailed representation the system establish connection between model parameters experimentally observed phenomena. In this article, different theoretical approaches most recent application examples are discussed. A simple example is used to showcase bene...