SU1260846A1 - Device for determining condition of structures in state of stress - Google Patents

Abstract

A device for determining the state of tense structures refers to a technique of non-destructive testing of materials and products by the method of amplitude separation of acoustic emission signals. The aim of the invention is to increase the reliability of the control and simplify the processing due to the possibility of separating the pulses into amplitude ranges that do not overlap each other. The acoustic emission signals are converted into an electrical signal by a transducer, amplified by a preamplifier, then the signal is amplified in the main amplifier, and then fed to an amplitude discriminator that has the required number of discrimination levels, and each signal that falls into one of the amplitude ranges will have its own digital signal. code. After the decoder, the signal hits only the counter of its amplitude range. In order to determine the connection of the parameters of the signals with the stage of development of the defect, the readings of the counters are recorded in pa with the clock frequency specified by the control unit. The control unit also provides gating signals to the decoder. The ratio of gating frequencies and clock cycles determines the accuracy of the recording process, and the duration of the cycle ensures the completeness of the use of information. 1 il. S (L S O s 4 Od

Description

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The invention relates to a technique for the cera-destructive testing of materials and products by the method of amplitude separation of acoustic emission signals.

The aim of the invention is to increase the reliability of the control and simplify the processing due to the possibility of separating the pulses into amplitude ranges that do not overlap each other.

The drawing shows a block diagram of a device for determining the state of stressed structures.

The device for determining the state of the tensioned structures contains a series-connected acoustic emission signal converter 1, a preamplifier 2, memory inputs 6, 7, ..., 7 memories, meter outputs 8 indicators 8

and input- outputs from input1 and

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littel 3 and amplitude discriminator 4, gated decoder 5, switched on-20 ny between the outputs of discriminator 4 and

-, . . , 6, and blocks between

6, ..., 6n 1 ° I-,

the control unit 9 is connected to the decoder 5, the counters 6 and the memory blocks 7, ..., 7.

The device works as follows.

The object's acoustic emission transducer 1 is located on the surface of the object. Acoustic emission signals arising at the location of the defect are converted into an electrical signal by transducer 1 and amplified by preamplifier 2. Then the signal is amplified in the main amplifier 3, and then fed to amplitude discriminator 4 having number of levels of discrimination. If the signal at the amplifier output exceeds the specified discrimination levels, then signal 1 appears at the corresponding outputs, and at the remaining outputs O, Thus, each signal that falls into one of the amplitude ranges corresponds to a digital code. When divided into four dia. 1260846

the zone is the following codes: 1, O, O, 0; 1, 1, .O, 0; 1, 1, 1.0; 1, 1, 1, 1, These codes correspond to certain outputs of the binary-decipher torus. Thus, the signal reaches only the counter of its amplitude range, and further analysis of the potential of the counter is not required for the analysis of a series of acoustic emission pulses.

In order to determine the relationship between the signal parameters and the stage of development of a defect or crack, the counters are recorded in the memory with 5 tervals set by control unit 9 (clock frequency).

The control unit 9 also provides gating signals to the decoder 5. The ratio of gating frequencies and clock cycles determines the recording accuracy

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process, and the duration of the cycle ensures the completeness of the use of information. The indication of the indications of each channel in the clock gives an idea of the ratio of the amplitudes, and the number of pulses in the cycles - about the frequency characteristics of the signals.

Claims (1)

Invention Formula A device for determining the state of tense structures, comprising a series-connected acoustic emission signal converter, a preamplifier, an amplifier and an amplitude discriminator, counters and indicators according to the number of discrimination levels, a control unit, characterized in that, in order to increase the control reliability, it is additionally equipped A gated decoder connected between the outputs of the amplitude discriminator and the inputs of counters, and memory blocks connected between the corresponding the outputs of the counters and the inputs of the indicators, and the outputs of the control unit are connected to the inputs of the decoder, the counters and the memory blocks. process, and the duration of the cycle ensures the completeness of the use of information. The indication of the indications of each channel in the clock gives an idea of the ratio of the amplitudes, and the number of pulses in the cycles - about the frequency characteristics of the signals. Invention Formula A device for determining the state of tense structures, comprising a series-connected acoustic emission signal converter, a preamplifier, an amplifier and an amplitude discriminator, counters and indicators according to the number of discrimination levels, a control unit, characterized in that, in order to increase the control reliability, it is additionally equipped A gated decoder connected between the outputs of the amplitude discriminator and the inputs of counters, and memory blocks connected between the corresponding the outputs of the counters and the inputs of the indicators, and the outputs of the control unit are connected to the inputs of the decoder, the counters and the memory blocks. Editor L.Povkhan Compiled by V.Evstratov Tehred L. Serdyukova Proofreader. M. Sharoshi Order 5223 / ft Draw 778 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 R /