SU1523999A1 - Apparatus for acoustoemission inspection of articles - Google Patents

Abstract

This invention relates to a technique for non-destructive testing of products. The purpose of the invention is to increase the reliability of control by continuously monitoring the health of the device. The device contains a generator of test pulses and a radiating electroacoustic transducer that generates mechanical oscillations in a monitored product, simulating acoustic emission signals, which are used to monitor the performance of the entire device between the reception of real acoustic emission signals. With the reception of signals, the device health monitoring process is automatically interrupted. 1 il.

Description

This invention relates to a technique for non-destructive testing of parts, using acoustic emission.

The aim of the invention is to improve the reliability of control due to the continuous monitoring of the health of the device.

The drawing shows a block diagram of a device for acoustoemission control.

The device for acoustic emission testing of products contains a series-connected receiving electroacoustic transducer 1, an amplifier 2 and a unit 3 for processing acoustic emission signals, a generator 4 of test pulses emitting an electroacoustic transducer 5, an indicator 6 of signals

control and shikatop 7 signals in acoustic emission, shaper 8 event duration, element 9, inverter) 0, first) 1, second 2 and third 13 analog keys, the output of amplifier 2 is connected to the input of shaper 8 event duration, the output of the latter is connected to the first the input element And 9, the second input of which is connected to the first output of the generator 4 test pulses, the second output of the generator 4 test pulses connected to the input of the first key II, the output of which is connected), is not connected to the electroacoustic transducer KiiM 5 And 9 is connected to the control outputs of the first 11 and second 12 keys, g; with inverter input 10, output

O1

O5

SS ffi

ss

which is connected to the y key to the fy input of the third key 13, the inputs of the second 12 and third 13 keys are connected respectively to the first and second outputs of the acoustic signal generation unit 3 of the 1st emission, and the outputs of the second 12 and third 13 keys are connected to the inputs of the ind1Pacher 6 signals, respectively control and indicator of 7 acoustic emission signals. In addition, the drawing shows a test item l t.

The event duration generator 8 can be pipolnated from a voltage source and connected in series: an envelope detector, a comparator (not shown), the second input of which is connected to the output of the voltage source and the delay element, the output of which serves as the output of the event duration 8, and the input of the envelope detector serves as an input to the Former B The device operates as follows

In the process of testing the product, acoustic emission signals are received by the receiving electroacoustic transducer, the signals are amplified by amplifier 2 and fed to processing unit 3, the output of which receives information about the investigated parameters of acoustic emission signals (intensity, amplitude, etc.).

In the intervals between the received acoustic emission signals, the device is monitored for performance, for which mechanical oscillations, simulating acoustic emission signals, are excited in the product. The control is implemented as follows.

The test pulse generator 4 generates square resolution resolution pulses of duration t, with a logic level 1, which are applied to the second input of the And 9 element,. To the first input of which, in the absence of signals in the controlled product, a signal of logical 1 is supplied from formalvat 8. Thus, on the signal of element I, a signal of logical 1 is generated, which is fed to the control key input 1 1, closes it for the time of action of the enable pulse At the same time, test pulses of duration 0 are emitted from the second output of generator 4

five

0

five

0

five

0

five

0

five

tp is somewhat shorter than the resolution pulse duration. The flpoBept- pulses are transmitted to the radiation of the electroacoustic transducer 5, and acoustic test pulses are excited in the material 14, which are received by the receiving electroacoustic transducer 1, amplified by the amplifier 2, and then processed by the unit 3 as ordinary acoustic emission signals, i.e. all informative parameters, such as intensity, akcituda, etc., which are received through the switch 12, which is closed for the duration of the action of the resolution pulse, are detected on the indicator 6 of the control signals.

The key 13 for the time tp of the action of the enable pulse is closed, since its control input is supplied from the inverter 10 by a logic signal O,

The test signals from the output of amplifier 2 are also fed to the driver of the event duration 8, where the radio pulse envelope is made of them, a pulse is formed equal to the duration of the envelope t, which through the delay element (not shown) sets the logical O level. The delay time of setting the logical O is chosen somewhat longer than the duration of the test pulses t p and tp,

In the absence of a delay element in the imaging unit 8, the test pulse would interrupt itself.

When acoustic emission signals appear, after amplification by amplifier 2, they arrive at the input of a duration generator 8, the output of which, with a delay of time t, produces a signal with a logic level O that completes the passage of the test pulses of the generator 4 for the entire time t of the presence of an acoustic emission signal, as well as some time after its termination (over time)

The key 11 during the time t is open due to the presence of a logical O at the output of the element And 9 for the same reason, the key 12 is open and information about the acoustic emission signals is not supplied to the indicator 6 of the control signals, but to the indicator 7 of the acoustic signals

i

emission through the lock key 13 during the time tj on the signal from the output of the inverter 10.

Thus, with a fully functional electroacoustic path of the device, one of the indicators 6 or 7 should have any signal present; the absence of signals on both sensors indicates the presence of a mismatch in the device-emission control.

Fore: Mul and Invention

A device for acoustic control of a device containing a series-connected transceiver electro-acoustic transducer, an amplifier and an acoustic emission signal processing unit, a test impulse generator, an acoustic transducer, an indicator of control signals and an indicator of acoustic emission signals, which is in order to increase the reliability of control.

Y6

it is equipped with an event duration shaper, an AND element, an inverter, first, second, and a third analog key, the amplifier output is connected to the event event shaper input, the last one output is connected to the first input of the AND element, the second input of which is connected to the first generator output check igtulsov, the second output of the generator kspperochnyh pulses connected to the input of the first key, the output of which is connected to the radiating electroacoustic

A transducer, the TERMINAL of the AND element, is connected to the control inputs of iiepBoro and the second key and to the input of the inverter, the output of which is Kjrio eH to the control input of the third

key, the inputs of the second and third key; they are connected respectively to the first and the second outputs of the acoustic emission signal processing unit, and the outputs of the second and third keys to the inputs of the control signal indicator and the acoustic emission signal indicator.

Claims (1)

A device for acoustic emission monitoring of products containing a serially connected receiving electro-acoustic transducer, an amplifier and an acoustic emission signal processing unit, a test pulse generator, an emitting electro-acoustic transducer, an indicator of control signals and an indicator of acoustic emission signals, characterized in that, in order to increase the reliability of control. 4 at 6 it is equipped with an event duration former, an And element, an inverter, first, second, and third analog keys, an amplifier output is connected to an event duration former, an output of the latter is connected to a first input of an And element, a second input of which is connected to a first output of a test generator pulses, the second output of the generator of test pulses is connected to the input of the first key, the output of which is connected to the emitting electro-acoustic transducer, the output of the element And is connected to the control inputs the first and second keys and with the inverter input, the output of which is connected to the control input of the third key, the inputs of the second and third keys are connected respectively to the first and second outputs of the acoustic emission signal processing unit, and the outputs of the second and third keys with inputs of the indicator of control signals and signal indicator acoustic emission.