www.polytec.com The dynamic properties of structures can be described with the aid of eigenfrequencies, attenuation and eigenshapes. Suitably measured, analyzed and classified, these properties can quickly determine quality for pass/fail selection of manufactured components. For many production inspection applications, Laser-Doppler vibrometers offer significant advantages over conventional, st...

wide range of planar structures in new technologies has attracted special consideration. in this research vibration behavior of plates with non-linear edges is investigated by means of finite difference (fd) method. for this issue, classical and analytical solutions for plates with linear edges were analyzed and mutual equations, needed for numerical calculation were extracted. by expanding the...

in this study, the free vibration of partially fluid-filled laminated composite circular cylindrical shell with arbitrary boundary conditions has been investigated by using rayleigh-ritz method. the analysis has been carried out with strain-displacement relations based on love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. after determining the...

Abstract—This paper has been investigated a technique that predicts the performance of a bar-type unimorph piezoelectric vibration actuator depending on the frequency. This paper has been proposed an equivalent circuit that can be easily analyzed for the bar-type unimorph piezoelectric vibration actuator. In the dynamic analysis, rigidity and resonance frequency, which are important mechanical ...

[Purpose] The purpose of this study was to investigate the effect of muscle vibration in the lower extremities in patients with Parkinson's disease (PD) during walking. [Subjects] Nine patients with PD participated in this study and were tested with and without vibration (vibration at 60 Hz). [Methods] Eight oscillators of vibration were attached to the muscle bellies (tibialis anterior, gastro...

This paper presents an investigation on the undesirable vibration of an oblique-stud stator frame in a large hydropower generator by means of experimental and finite element (FE) analysis. First, field experimental tests were performed, and the results indicate that the main vibration component comes from electromagnetic factors. Then, a 2D-magnetic and 3D-mechanical FE model was developed to i...

Vibration Analysis Tests (VAT) and Acoustic Emission tests (AE) are used in several industrial applications. Many of them perform analysis in the frequency domain. Peaks in the power density spectrum hold relevant information about acoustic events. In this paper we propose a novel method for feature extraction of vibration samples by analyzing the shape of their auto power spectrum density func...

The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s), amplitude (0 mm-1 mm), bed height (0.1 m-0.4 m) as well as four kinds of particles (belonging to Geldart's B and D groups). The axial and ra...