6 research outputs found
Dependence the Integrated Energy of the Electromagnetic Response from Excitation Pulse Duration for Epoxy Samples With Sand Filler
Results of research of influence of the excitation pulse duration on the parameters of the electromagnetic response of epoxy samples with filler the quartz sand presented in the paper. The electric component of a response was registered by the capacitive sensors using a differential amplifier. Measurements were carried out at two frequencies of the master generator of 65 kHz and 74 kHz. The pulse duration was changing from 10 to 100 microseconds. The stepped sort of dependence of the integrated oscillations energy in the response from duration of the excitation pulse was discovered. The conclusion was made about the determining role of the normal oscillations in formation of such dependence
Features of the Amplitude-Frequency Characteristics of Electromagnetic Emission during Uniaxial Compression of Dielectric Composites
We have studied the electromagnetic emission from samples of epoxy resin filled with sand subjected to uniaxial compression . Capacitive sensor measures the electrical component of the response when excited electromagnetic emission of ultrasonic pulse using a differential amplifier. It was shown the influence of the load on the spectral signal characteristics: with increasing pressure, the formation of bands at frequencies corresponding to possibly quasi-Rayleigh waves generation. It is concluded that the use of the experimental geometry studies the main contribution to the response of electromagnetic emissions create born normal vibrations, which are damped standing waves
Study of the effective filtration method applicability for the control of composite materials stress-strain state
The paper presents the results of experimental studies on the possibility of applying the effective filtration principle in the developing non-destructive testing methods. The presented results make it possible to conclude that the optimal filtration principle can be applied in the further development of methods for determining the absolute values of the stress-strain state of similar objects. It is necessary for its implementation to have impulse responses of similar objects for given stress-strain state values
Determining the effect of the duration of alternating acoustic excitation on electromagnetic response parameters of the composite
The paper presents the results of the experimental investigation dealing with the effect of the alternating excitation acoustic pulse duration on the parameters of the electromagnetic emission caused by interaction of acoustic vibrations with inhomogeneities in the sample structure, piezoelectric inclusions and media interfaces of different dielectric properties. The model sample was epoxy resin with quartz sand as filler. The electrical component of the response was recorded with a capacitive transducer. The acoustic pulse was generated by piezoelectric transducer at frequencies of 57 kHz, 65 kHz, 74 kHz, 87.5 kHz and 94.5 kHz with the pulse duration varying from 10 ?s to 100 ?s. It is shown that the reduced duration of the acoustic action leads to dominance of the intrinsic frequency in the spectrum. A contribution of tensile pulses to acoustic electromagnetic transformation response generation is revealed
Development the Adjusted Mathematical Model of Responses in the Nondestructive Testing Defectiveness Method Based on the Mechanoelectrical Transformations
The improving version the responses mathematical model when using the method of mechanoelectrical transformations for nondestructive testing of defects in composite dielectric materials was examined. The refinement is conditioned by necessity of account of the frequency-dependent attenuation. For this has been used spectral approach: decomposition of excitation pulse in range and the formation of the amount each attenuate spectral component with the sample pulse response
Study of the effective filtration method applicability for the control of composite materials stress-strain state
The paper presents the results of experimental studies on the possibility of applying the effective filtration principle in the developing non-destructive testing methods. The presented results make it possible to conclude that the optimal filtration principle can be applied in the further development of methods for determining the absolute values of the stress-strain state of similar objects. It is necessary for its implementation to have impulse responses of similar objects for given stress-strain state values