UA150325U - Method for measuring the speed of ultrasonic waves in polymer nanocomposites by using the calibration labels - Google Patents

Abstract

A method for measuring the speed of ultrasonic waves in polymer nanocomposites by using the calibration labels is to generate and measure the ultrasonic waves by using the sequentially installed frequency meter (1), frequency divider generator (3), rectangular pulse generator (4), piezoelectric transducer (5) which is mounted on a sample (7) of a polymer nanocomposite through a buffer of fused quartz (6), resonant amplifier (8) and a two-beam oscilloscope (9). At the same time, the rectangular pulse generator (4) is connected to the two-beam oscilloscope (9) directly for scan synchronization, the thickness of the sample (7) of the polymer nanocomposite is h, and during the transmission of the ultrasonic wave, the frequency f of the ultrasonic wave in the sample (7) of polymer nanocomposite, is determined. After this, the speed of the ultrasonic wave according to the formula УУЗ=2h/T=2h/f is calculated. After the frequency meter (1), a frequency synthesizer (2) is additionally installed, and which is directly connected to the oscilloscope (9), which is made as two-beam with the input U1 and input U2, and the ultrasonic wave U is sent to the input U1 and the calibration marks UMK generated by the frequency synthesizer (2) are fed to the input U2. The maxima of each echo pulse of the ultrasonic wave U reflected from the sample (7) of the polymer nanocomposite are combined with the maxima of the calibration marks UMK, which results in the number n of marks between the corresponding maxima of the echo pulses U. The frequency f of the ultrasonic wave in the sample (7) of the polymer nanocomposite is determined by the formula f=fMK/n, and the speed of the ultrasonic wave is determined by the formula VУЗ=2h=f=2hf(fMK/n).

Description

The useful model belongs to the methods of researching polymer nanocomposites using ultrasound and can be used to measure the velocity of ultrasonic waves (UZH) in polymer nanocomposites used in radio engineering, instrument engineering, aviation and space engineering, and automotive engineering. There are well-known methods of measuring the speed of ultrasonic waves by combining echo signals (1-6). The disadvantage of the known methods is related to the error caused by the visual combination of echo signals on the oscilloscope screen.

The closest analogue is the method of measuring the velocity of ultrasound transmission, which consists in the generation and measurement of ultrasound with the help of a serially installed frequency meter, a frequency divider generator, a rectangular pulse generator, a piezo transducer, which is installed on a polymer nanocomposite sample through a fused quartz buffer, a resonant amplifier and single-beam oscilloscope. At the same time, the generator of rectangular pulses is connected to the single-beam oscilloscope of the direction. During the transmission of ultrasound, the frequency of its passage of ultrasound in the sample is determined. After passing the ultrasound, the rate of passage of this ultrasound is calculated according to the formula: Muz-2N/1T-Phi.

There is a known method of measuring the propagation time Li of an acoustic pulse, in which an acoustic pulse is emitted and received and the time of its arrival is determined by selecting one half-wave Ai/2 of the acoustic pulse by fixing its transition through 0, in order to increase the accuracy of measurements, the second arrival time is determined half-wave L2/2 by fixing its transition through 0, and the propagation time Di of the acoustic pulse is determined by the specified arrival times, taking into account the ratio of the number of half-waves Ag/2 between them and the number n of half-waves A/2 from the beginning of the pulse to the first of the specified half-waves Di- and2-her (7). The method has disadvantages: the impossibility of measuring the speed of ultrasound Muz in thin polymer nanocomposites with a thickness of Нп-0.1-4 mm, since with such dimensions of polymer nanocomposites, echo signals are directed in short time intervals of the order of AT and μs. In addition, this method is characterized by low accuracy, and therefore insufficient reliability, the complexity of the design and the relatively high cost of devices that implement this method.

The basis of the proposed useful model is the task of increasing the accuracy and reliability of measuring the speed of ultrasonography of Muz at the same time as ensuring the possibility of its

From use for measurement in thin polymer nanocomposites with a thickness of n-0.1--1 mm.

The task is solved by the fact that in the method of measuring the speed of passage of ultrasound

Muses in a polymer nanocomposite with the help of calibration marks, which consists in the generation and measurement of an ultrasonic wave with the help of a serially installed frequency meter (1), a frequency divider generator (3), a rectangular pulse generator (4), a piezo transducer (5), which is installed on a sample (7) of a polymer nanocomposite through a fused quartz buffer (6), a resonant amplifier (8) and a two-beam oscilloscope (9), while the rectangular pulse generator (4) is connected to the two-beam oscilloscope (9) directly for scanning synchronization, thickness of the sample (7) of the polymer nanocomposite is n, and during the transmission of the ultrasound scan, the frequency of the ultrasound scan in the sample (7) of the polymer nanocomposite is determined, after which the speed of this ultrasound scan is calculated using the formula

Muz-21/T1-2Phi, according to the useful model, after the frequency meter (1), a frequency synthesizer (2) is additionally installed, which is connected to the oscilloscope (9) of the direction, which is made of two beams with an input |; and the input I", at the same time, ultrasound is sent to the input Oi, and calibration marks generated by the frequency synthesizer (2) are applied to the input O2, while combining the maxima of each echo pulse of the ultrasound reflected from the sample (7) of the polymer nanocomposite, with by the maxima of the iMk calibration marks, as a result of which the number of n marks between the corresponding maxima of the echo pulses is obtained, as a result of which the frequency of the passage of ultrasound in the sample (7) of the polymer nanocomposite is determined by the formula y-imk/l, and the speed of the passage of ultrasound is determined by the formula Muz -2PhiI-2Ph(imk/p).

A useful model is explained by the drawings in Fig. 1, Fig. 2. In Fig. 1 shows a schematic representation of echo pulses and calibration marks. The claimed method is carried out using a device, the block diagram of which is shown in Fig. 2.

The device consists of a frequency counter (1), a frequency synthesizer (2), a frequency divider generator (3), a rectangular pulse generator (4), a piezo transducer (5), a fused quartz buffer (6), a sample of the measured polymer nanocomposite (7) , resonant amplifier (8), two-beam oscilloscope (9).

The method is carried out as follows. Harmonic, highly stable sinusoidal oscillations, used as calibration marks, from the output of the frequency synthesizer (2) are fed to the frequency meter (1) to measure the frequency and trigger the frequency divider generator (3). The choice of the frequency division coefficient is determined by the amount of ultrasound attenuation in the polymer nanocomposite (7). Rectangular negative pulses from the output of the frequency divider generator (3) start the probing rectangular pulse generator (4), which produces negative pulses of greater amplitude for the excitation of ultrasound in the polymer nanocomposite (7) using a piezo transducer (5). The generator (4) also forms rectangular pulses to start the sweep generator of the two-beam oscilloscope (9). Ultrasonography propagates through a buffer made of fused quartz (b), reflected from the boundary between the buffer-sample and the sample-air, transformed a second time by a piezo transducer (5), the electrical signal enters the input of the resonant amplifier (8).

Amplified reflected signals are applied to the first input of a two-beam oscilloscope (9) and are observed on the screen in the form of a decaying sequence of echo pulses О (10), highly stable, harmonic oscillations are applied to the second input of the oscilloscope with synchronous scanning of both beams, which are used as calibration marks Ohm ( 11), from the output of the frequency synthesizer (2), shown in the inset of Fig. 1.

By changing the frequency of the calibration marks of the harmonic oscillations of the frequency synthesizer (2) between the corresponding maxima of the echo pulses ОО (10), on the screen of the two-beam oscilloscope (9) the same number of calibration marks n Ωk (11) are placed and at the same time the maximum of each echo pulse Ш (10) is combined with the maximum of harmonic oscillations Ohm (11):

Thus, the measurement of the time T of the ultrasound passage in the polymer nanocomposite is reduced to the measurement of the frequency of the placed calibration marks imk and the calculation of the number of periods of these marks p (11) between the corresponding maxima of echo pulses (10) according to the formula: T-1/-p/mk.

The technical and economic advantages of a useful model over similar ones belonging to the most advanced technical solutions consist in simplifying the design and reducing the cost of devices that implement the proposed method. The task of measuring the speed of passage of an ultrasonic Uuz wave in a polymer nanocomposite has been completed.

Sources of information: 1. Ahlers D. Measurement of very small changes in the speed of sound and their application to the study of a solid body. - Physical acoustics, Moscow, Mir. - 1969. - T. IM, ch. A. - pp. 322-344. 2. Kryshtal M.A., Golovyn S.A. Internal friction and the structure of metals, Moscow,

Metallurgy. - 1976. - P. 83-84. 3. Novik A., Berry B. Relaxation phenomena in crystals, Moscow, Atomizdat. - 1975.

Zo 4. Kuznetsov N.A., Potekhin D.S., Tarasov I.E., Teteryn E.P. The method of simultaneous determination of the velocity of longitudinal and shear acoustic waves. Patent for the invention No. 2382358. RF, application 7.11.2006; published 20.02.2010. 5. Sokolov I.V., Kachanov V.K. Timofeev D.V., Konov M.M., Synitsn A.A., Rodyn A.B. The method of ultrasonic shock-impulse thickness measurement. Patent for the invention No. 2422769. RF, application 30.03.2010; published 27.06.2011, Bull. Mo. 18. - 9 p.m. b. Onanko A.P., Zabolotnyi M.A., Dmytrenko O.P., Kulish M.P. etc. The method of determining the absorbed dose of radioactive exposure to metals. Patent for the invention No. 98078. Ukraine, application 21.04.2011; published 10.04.2012, Bull. Mo 7. - 7 p. 7. Author's Certificate of the USSR Mo 1173299, (301М 29/00. Publ. 15.09.1985. (closest analogue).

Claims (1)

USEFUL MODEL FORMULA The method of measuring the velocity of the ultrasonic wave in a polymer nanocomposite with the help of calibration marks, which consists in the generation and measurement of an ultrasonic wave using a frequency counter (1), a frequency divider generator (3), a rectangular pulse generator (4), n' isoconverter (5), which is installed on a polymer nanocomposite sample (7) through a fused quartz buffer (6), a resonant amplifier (8) and a two-beam oscilloscope (9), while the rectangular pulse generator (4) is connected to a two-beam oscilloscope ( 9) directly to synchronize the scanning, the thickness of the sample (7) of the polymer nanocomposite is Pp, and during the transmission of the ultrasonic wave, the frequency of the passage of the ultrasonic wave in the sample (7) of the polymer nanocomposite is determined, after which the speed of the passage of the ultrasonic wave is calculated according to the formula Uuz-2n/ T-2Nkhi, which differs in that after the frequency meter (1), a son is additionally installed frequency thesator (2), which is connected to the oscilloscope (9) of the direction, which is made of two beams with an input Ш; and the input I", and the ultrasonic wave | is sent to the input Oi, and the calibration marks Ohm generated by the frequency synthesizer (2) are applied to the input O2, while combining the maxima of each echo pulse of the ultrasonic wave O reflected from the sample (7) of the polymer nanocomposite, with the maxima of the calibration marks Ohm, as a result of which the number of n marks is obtained between the corresponding maximums of the echo pulses of the OO, the frequency of the passage of the ultrasonic wave in the sample (7) of the polymer nanocomposite is determined by the formula waves are determined by the formula Muz-2Phi-2Ph (Imk/p). и : их и п Ж skuee С шт UNK В и sf: A AH A K B AN i A De A NA BOZHOYU ge tires Fig. 1 : | I am! and Mr Fig. and