A dynamic method for mass detection, considering attaching positions of micro-objects on microcantilevers, is introduced. Two models based on the Rayleigh– Ritz method were developed for analyses of the first flexural and the first torsional modes of a “cantilever– mass” system, respectively. Due to one-to-one correspondence between the longitudinal adhering positions of the micro-objects and t...

The primary goal of the this project was to demonstrate the feasibility of detecting changes in shaft natural frequencies (such as those associated with a shaft crack) on rotating machinery in electric power generation plants using non-contact, nonintrusive measurement methods. During the operation of power plant equipment, torsional natural frequencies are excited by turbulence, friction, and ...

In this paper, free longitudinal vibration of nanorods is investigated from the wave viewpoint. The Eringen’s nonlocal elasticity theory is used for nanorods modelling. Wave propagation in a medium has a similar formulation as vibrations and thus,  it can be used to describe the vibration behavior. Boundaries reflect the propagating waves after incident. Firstly, the governing quation of nanoro...

In this work we present a methodology for the accurate numerical computation of the rovibrational G matrix in any molecule. A C++ program is developed to apply this methodology. Using polymorphism, the program can handle the output of any of the available electronic structure codes. The objective is to compute the kinetic contribution to the rovibrational Hamiltonian from the results of molecul...

The problem of coupled flexural-torsional nonlinear vibrations of a piezoelectrically-actuated microcantilever beam as a typical configuration utilized in microcantilever-based sensing is being investigated. The actuation and sensing are both facilitated through bonding a piezoelectric layer (here, ZnO) on the microcantilever surface. Considering different geometrical configurations for the bea...

Based on the model of Higgins and Goodman, we describe a dynamically generated fuzzy neural network (DGFNN) approach to control, from input–output data, using on-line learning. The DGFNN is complete with the following powerful features drawn or modified from the existing literature: (1) a small FNN is created from scratch—there is no need to specify initial network architecture, initial members...

Rotor dynamics plays an important role in many engineering fields such as gas turbine, steam turbine, reciprocating and centrifugal compressors, the spindle of machine tools, and so on. Owing to the growing demands for high power, high speed, and light weight of the rotor-bearing system, computations of critical speeds and steady-state response at synchronous and sub critical resonances become ...

A novel design of a MEMS torsional resonant magnetometer based on Lorentz force is presented and fabricated. The magnetometer consists of a silicon resonator, torsional beam, excitation coil, capacitance plates and glass substrate. Working in a resonant condition, the sensor's vibration amplitude is converted into the sensing capacitance change, which reflects the outside magnetic flux-density....

Two types of prime movers are continuously applied for rotating machinery: mechanical and electric drives. This tutorial focuses on electric drives, which are actually composed of separate components: electric motor, frequency converter (optional), and electric network including transformers. The main aim of this tutorial is to explain the phenomena of electric drives related to the torsional v...