In this article, the design of rectangular symmetric bimorph piezoelectric ceramic transducers with loose and fixed edges and with parallel electric excitation is studied. Rectangular piezoelectric ceramic transducers in cosinusoidal flexural vibration with straight and parallel nodal lines of vibration are studied. The radiation of the transducer in a plane perpendicular to the surface of the ...

The observed anisotropies of surface vibrations for unreconstructed FCC metal (110) surfaces are often reversed from the “common sense” expectation. The source of these reversals is investigated by performing ab initio density functional theory calculations to obtain the surface force constant tensors for Ag(110), Cu(110) and Al(110). The most striking result is a large enhancement in the coupl...

A new type of electrostatic microgenerator is presented that converts mechanical microvibrational energy into electric energy. The energy conversion mechanism is as follows. External microvibrations are transmitted to the device frame. The thin electret layer sputtered to the silicon substrate surface was fixed on the frame and the moving electrode was fixed by a weak suspension and comes into ...

Humans can detect and discriminate between fine variations of surface roughness using active touch. It is hitherto believed that roughness perception is mediated mostly by cutaneous and subcutaneous afferents located in the fingertips. However, recent findings have shown that following abolishment of cutaneous afferences resulting from trauma or pharmacological intervention, the ability of subj...

We consider the effect of an external bias voltage and the spatial variation of the surface potential, on the damping of cantilever vibrations. The electrostatic friction is due to energy losses in the sample created by the electromagnetic field from the oscillating charges induced on the surface of the tip by the bias voltage and spatial variation of the surface potential. A similar effect ari...

Passing underground trains induce vibrations transmitted to the ground surface and the nearby structures. Ordinarily, these vibrations do not result in structural damage but can harm nonstructural elements and disturb the occupants. These effects are more pronounced when evaluating buildings like hospitals, laboratories, museums, etc., and their assessment is an important design need. To respon...

The evaluation and control of the trains induced vibrations needs even more attention in the case of underground tracks which passes near to monuments and historical sites. The rail corrugations which occur due to the wheels’ impulse loads during the operation period of underground railway tracks, usually amplify the ground borne noise and vibration. In the current study, the mentioned phenomen...