SU974257A1 - Device for checking materials by acoustic emission - Google Patents

Description

tS) DEVICE FOR ACOUSTIC EMISSION CONTROL OF MATERIALS

one

The invention relates to non-destructive testing and can be used to control materials by acoustic emission method.

A device comprising a converter, a preamplifier, an amplifier, a discriminator and a recording device 1 J connected in series is known.

The disadvantage of it is the inability to assess the results of control in the process of testing materials, due to the fact that the device does not have a unit for comparing the recorded parameters with the specified rejection level.

The closest in technical essence to the present invention is a device for acoustics-emission monitoring of materials, comprising a transducer connected in series, an amplifier and a pulse shaper connected by a follower.

but the first counter and the first digital-to-analog converter, a clock pulse generator, the output of which is connected to the installation input of the first counter, and a comparison unit

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The disadvantage of it is the small reliability of the control, due to the fact that the rejection level

The fQ of the comparator unit is established for testing. This is unacceptable for materials with a significant variation in the magnitude of the intensity of the acoustic emission network (AE from product 5 LIA to the product (electrical porcelain, ceramics).

The purpose of the invention is to increase the reliability of the control.

The goal is achieved by the fact that a device for, a1 ustic emission emission control of materials containing a transducer connected in series, an amplifier and a pulse shaper. connected in series the first counter and the first digital-to-analog converter, a clock pulse generator, the output of which is connected to the installation input of the nepisoro counter, and a comparison unit, is equipped with a first AND circuit connected between the pulse shaper and the first counter, the first divider connected between the first digital-analog the converter and the first input of the comparator unit, connected in series and connected to the output of the pulse former by the second AND circuit, the second counter, the second digital-analogue transducer the distributor and the second divider, the output of which is connected to the second input of the comparison unit connected in series by the third circuit I, the third counter and the three hook, the direct output of which is connected to the second input of the first circuit AND, the inverse output is connected to the second inputs of the second and third circuits And, and the input of the third circuit And connected to the output of the generator of clock pulses. The drawing shows the proposed my device. The device contains a converter 1 connected in series, an amplifier 2 and a pulse shaper 3 connected in series to the first counter k and the first digital-to-analog converter 5, a generator of 6 clock pulses, the output of which is connected to the installation input of the first counter A, and the comparison unit 7. The device also contains the first circuit 8 AND connected between the driver of 3 pulses and the first counter C of the first divider 9 connected between the first digital-to-analog converter 5 and the first input of the comparator 7, connected in series and connected to the output of the driver of the 3 pulses of the second circuit 10 And the second counter 11, the second digital-to-analog converter 12, and the second divider 13, the output of which is connected to the second input of the comparator unit 7, connected in series to the third circuit 14 AND, the third counter 15 and the trigger 16, direct to turn connected to the second input of the first AND circuit 8, an inverse output coupled to an input Auto rymi second AND circuit 10, and the third circuit and k and the input of the third AND circuit and connected to the output 6 of the generator clock pulses. The device works as follows. On the basis of calibration tests, which include registering the intensity of AE when loading a batch of products prior to destruction, the interval on the scale of loads of averaging of intensity of AE is determined, corresponding to the flat section of dependence of the intensity of AE on load (mechanical stresses). For the given averaging interval, the corresponding number AND periods of the generator 6 clock pulses is determined, the counter doi is used as the third counter 15, and the division factor of the second divider 13 is set to and. The averaged intensity of the AE increased by a factor of K is taken as the rejection level, respectively, the division factor of the first divider 9 is set to K. During the control of the material of the products, the converter 1 is excited by the signals of the AE, which are then fed to the amplifier 2 and the driver 3 pulses. The generated pulses arrive at the inputs of the first circuit 8 AND and the second circuit 10 AND, until the load reaches the value corresponding to the beginning of the selected averaging period, the clock pulse generator 6 is not turned on, and the first counter, second counter 11, third counter 15 and trigger 16 are set to - zero state. At the same time, at the direct input of the trigger 16, the potential is O and the first circuit bI is closed, and at the inverse output of the trigger 16 there is a potential that opens the second circuit 10I and the third scheme I.I. At the beginning of the averaging period, the generator 6 clock pulses turn on and the pulses through the third circuit 1 and pass to the third counter 15. At the same time, the pulses from the driver 3 pulses, corresponding to the AE signals, flow through the second circuit 10 and to the second counter 11. After the third counter 15 receives the pulses of the generator, the clock pulses a pulse appears at its output, which translates. trigger 16 to another state. At the same time, the inverse output of the trigger 16 shows a zero potential, which closes the second circuit 10 And the third circuit 1 I. The third circuit And ceases to pass the generator pulses 6 clocks x to the third counter 15 and therefore the trigger 16 does not change em its state. The pulses from the imaging unit of 3 pulses cease to flow to the second counter 11 and a number equal to the number of AE pulses per vi generator clock cycle of 6 clock pulses remains in it. Using a second D / A converter 12 and a second divider 13, a potential proportional to the average-AE intensity over a period appears at the second input of the comparison unit 7. At the same time, the first scheme 8 AND opens up on the

direct output of the trigger 16 potential and pulses from the generator of 3 pulses arrive at the first counter 4. At the input of the installation at zero of the first counter, C, the clock pulses arrive, therefore at the end of each generator period 6 pulses in the first counter A will be recorded a number equal to the number of pulses AE for this period, i.e. intensity of AE. Thus, a potential proportional to the intensity of the AE and reduced by a factor of K in the first divider 9 is applied to the first input of the comparator unit 7. If this potential exceeds-. the potential at the other input, then at the output of the comparison unit 7 it appears. pulse that can be used to stop the loading device.

Thus, the invention allows for $ pulses.

It is necessary to increase the reliability of the control due to the fact that the instant of a sharp increase in the intensity of AE. is determined in the device as the instant of exceeding the level measured during the loading of the test sample.

between the pulse driver and the first counter, the first divider connected between the first digital-to-analog converter and the first input of the comparison unit, connected in series and connected to the output of the second pulse driver, the second And circuit, the second counter, the second digital-analog converter and the second divider whose output is connected with the second input of the comparison unit, connected in series by the third AND circuit, a third counter and a trigger, the direct output of which is connected to the second input of the first AND circuit, nversny output connected to second inputs of the second and third AND circuits, and the "third input of the AND circuit connected to the output of clock generator

Sources of information taken into account in the examination

1.P. Sharp Non-destructive testing methods. M., Mir, 1972, p. i.

2. Flaw detection. Number 5, 1976, p. (prototype). 7 claims An apparatus for acoustic emission monitoring of materials comprising a transducer connected in series, an amplifier and a pulse shaper connected in series to a first counter and a first digital-to-analog converter, a clock generator, the output of which is connected to the installation input of the first counter and a comparator unit characterized in order to increase credibility. it is equipped with the first And circuit, turned on Vrr

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Claims (1)

Claim A device for acoustic emission monitoring of materials, comprising a converter connected in series, an amplifier and a pulse former, connected in series with a first counter and a first digital-to-analog converter, a clock pulse generator, the output of which is connected to the installation input of the first counter, and a comparison unit, characterized in that , in order to increase the reliability, it is equipped with a first circuit And included between the pulse shaper and the first counter, the first divider included between the first m digital-to-analog converter and the first input of the comparison unit, connected in series and connected to the output of the pulse shaper by the second circuit And, the second counter, the second digital-to-analog converter and the second divider, the output of which is connected to the second input of the comparison unit, connected in series to the third circuit And, the third counter and trigger, the direct output of which is connected to the second input of the first circuit And, the inverse output is connected to the second inputs of the second and third circuits And, the input of the third circuit And is connected nen yield clock generator.