Development of an acoustoelectric method for determining the porosity of dielectric materials

The regularities of acoustoelectric transformations in cement stones with different water-to-cement ratios are studied. A physically substantiated acoustoelectric method for determining the porosity of dielectric materials is proposed.     

Mechanoelectric transformations in cement-sand composites under the action of cyclic alternating-sign temperature variations

It is established that a change in the strength of porous composite materials under the action of cyclic alternating-sign temperature variations leads to a high-frequency shift in the center-of-gravity of the amplitude-frequency characteristics of the electric response of samples to a pulsed impact excitation.     

Development of a nondestructive method for testing the strength of concrete with a faulted structure based on the phenomenon of mechanoelectric transformations

An algorithm for nondestructive testing of concrete strength based on the parameters of an electric response to elastic impact excitation has been developed based on experimental studies. The error in determining the strength using the proposed algorithm is 9% for heavy-weight concrete.     

Experimental and theoretical investigation of the characteristics of an electric response to an elastic impact excitation of piezo-containing heterogeneous materials

Experimental investigations were performed on the influence of flaws on the characteristics of an electric response of gypsum-sand specimens under impact excitation. A physico-mathematical model of an electric response to an elastic impact excitation of piezo-containing heterogeneous materials was developed. Using the apparatus of continuum mechanics, the parameters of an electric signal from a dielectric specimen exposed to a pulsed action were theoretically calculated and agreement with the experimental results was observed.     

High repetition rate CW fundamental soliton generation using multisoliton pulse compression in a varying dispersion fibre

A new method is proposed for fundamental soliton train generation from a CW double-frequency signal. This scheme uses multisoliton precompression in a fibre with sharply increasing dispersion followed by adiabatic compression in a dispersion decreasing fibre.<>     

Relation between Quality of Bonds among Components of Composite Materials and Parameters of Electromagnetic Response to Shock

Transformations of mechanical to electric pulses on the interface between a host material based on stiffened cement and inclusions have been investigated. An electromagnetic method for assessing the quality of adhesion bonds between components of composite materials has been suggested and physically tested.     

The amplitude of electric response as a function of the spatial arrangement of filler particles in mechanically excited concrete

Experimental investigation is performed and a model is suggested of the phenomenon of electric signal generation under conditions of mechanical excitation of a medium consisting of a dielectric immersed in a poor conductor.     

Development of the technique of nondestructive testing of heterogeneous dielectric materials based on utilization of the mechanoelectric transformation phenomenon

Defects of different types and sizes in a material are shown to result in variations in the spectral characteristics of electric responses to pulsed mechanical excitation of heterogeneous materials. General regularities reside in an increase in the size and concentration of defects that yields a decrease in the magnitude and quality factor of the principal spectral maximum and variations in the spectral composition of the electric response.     

Effect of cyclic freezing–thawing on the parameters of electric response to elastic shock excitation of reinforced concrete

General and distinctive features have been established for the effect that cyclic freezing–thawing has on the parameters of electric response to elastic shock excitation in steel and glass-fiber reinforced concretes. Based on frequency-time and autocorrelation analyses, criteria are suggested for assessing the deterioration degree of reinforced concrete under alternating-sign temperature action.     

Interconnection of an electric response with the parameters of a mechanical excitation and the elastic and dimensional characteristics of heterogeneous building materials

The amplitude-frequency characteristics of electric responses to elastic impact excitations of building materials were investigated. It was established that the frequencies of the main spectral peaks of electric signals are determined by the impact duration, dimensions of a specimen, and velocities of longitudinal and transverse acoustic vibrations. The ratio of the magnitudes of these spectral peaks is determined by the spectrum of the impact excitation, the shapes of articles, and the geometries of the testing experiments.