SU1322107A1 - Device for random vibration testing of articles - Google Patents

Abstract

This invention relates to a testing technique. The aim of the invention is to increase the reliability and accuracy of the tests by using a sequential chain of selective circuits to form bursts and dips in the spectrum of the excitation signal and to introduce constant monitoring of the parameters of the frequency selector circuits of the driver. A device for testing products for random vibration comprises a noise generator 1, a random signal from the output of which is fed to the input of a wideband filter 2, which forms an average level of the modulated vibration spectrum. From the output of the broadband filter 2, the signal is fed to the first input of the first adder 3, the second input of which simultaneously receives a signal from the output of the harmonic signal generator 21. Then, the sum signal goes to the first driver, where on summation of block 4 a dip or surge is formed at the frequency of the narrowband tunable filter amplifier 5. The dip depth or the burst value is controlled by the gain of the controlled attenuator 6. With the N-ro driver, the wideband random signal bursts or dips at the corresponding frequencies are fed through the following reject filter 9 to the power amplifier 10 and to the recording and storage circuit 11. of the dynamic characteristic of the device, where there is a constant control over the parameters of the frequency-selective circuits of the drivers. 1 il. with e (L 00 to

Description

The invention relates to a testing technique and can be used to test products for the effects of broadband random vibration with a given energy spectrum.

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The purpose of the invention is to increase the reliability and accuracy of the tests by using a consistent chain of electoral chains to form bursts and dips in the spectrum of the exciting signal and introducing a constant control over the parameters of the frequency selective circuits of the driver,

The drawing shows the block diagram of the device.

The device contains a series-connected noise generator 1, a broadband filter 2, a first adder 3, N drivers, each of which includes a summing unit 4, the output of which is the output of the driver, and the first input - the input of the driver, and the series-connected narrow-band filter amplifier 5, a controlled attenuator 6, a phase inverter 7 and a phase shifter 8, the output of which is connected to the third input of the summing unit 4, the input to the second input of the summing unit 4, the first input of which is connected to the input of the narrowband filter a trap amplifier 5, a trailing reject filter 9 and a power amplifier 10, a recording and storage circuit 11 of a dynamic characteristic of the device, the first input of which is connected to the output of the summing unit 4 of the N-ro driver and which consists of a series-connected tracking band-pass filter 12, voltage-code converter 13, random access memory unit 14 is connected to the output of the read address generation unit 19 and the third input of the RAM unit 14, and the first input to the second input of the 14 RAM unit and the output of the frequency converter 18 one, the second input of which is connected to the second input of a sideband filter 12 and the second input of the device recording and storing the dynamic characteristic of the device, the first input of which is connected to the first input of the following bandpass filter 12, and a harmonic generator 21 whose output is with the second input of the first 5 adder, the second input of the following reject filter 9 and the second input of the recording and storage circuit 11 of the dynamic characteristic of the device.

The device works as follows.

A random signal from the output of the noise generator I is fed to the input of the wideband filter 2, which forms the average level of the simulated vibration spectrum. From the output of the wideband filter 2, the signal goes to the first input of the first adder 3, the second input of which simultaneously receives a signal from the output of the generator 21 harmonic signal. Then, the total random signal is fed to the input of the narrowband tunable in frequency and Q-factor of the filter, a force 5 and a summing unit 4 of the first driver. Assuming that at the resonant frequency of any of the narrow-band tunable filter amplifiers 5 the phase shift of the output signals relative to the input signals is zero, the summing block 4 will subtract signals from the outputs of the phase inverter 7 and phase shifter 8, corresponding to 40

va (ram), the converter 15 is code-timed to the second and third inputs of the summation interval and the second adder 16, the tagging unit 17, the frequency-code converter 18, the readout address forming unit 19 and the synchronization unit 20, - 50 of the resulting dip regulate the kosfrauding unit 4 of the corresponding shaper, from the signal of the average level arriving at the first input of the summing unit 4, wherein the depth

It is connected to the second input of the voltage-code converter 13, the third input of the tag formation unit 17, the input of the link to form the address of the link, the frequency-code input of the converter 18 and the third input of the second adder 16, the second input of which is connected to the output of the generator 17 tagging, the second input of which

associated with the output of the read address generation unit 19 and the third input of the 14 RAM unit, and the first input is connected to the second input of the 14 RAM unit and the output of the frequency-code converter 18, the second input of which is connected to the second input of the dual band-pass filter 12 and the second input of circuit II for recording and storing the dynamic characteristic of the device, the first input of which is connected to the first input of the following bandpass filter 12, and a harmonic signal generator 21, the output of which is connected to the second input of the first adder, the second input of the following rejecting phi Lterra 9 and the second input of the circuit 11 for recording and storing the dynamic characteristics of the device.

The device works as follows.

A random signal from the output of the noise generator I is fed to the input of the broadband filter 2, which forms the average level of the simulated vibration spectrum. From the output of the wideband filter 2, the signal arrives at the first input of the first adder 3, the second input of which simultaneously receives a signal from the generator output 21 of the harmonic signal. Next, the total random signal is fed to the input of a narrow-band tunable in frequency and quality factor of the filter amplifier 5 and the summing unit 4 of the first shaper. Assuming that at the resonant frequency of any of the narrow-band tunable filter amplifiers 5 the phase shift of the output signals relative to the input signals is zero, the summing block 4 will subtract signals from the outputs of the phase inverter 7 and phase shifter 8, corresponding to

At the second and third input, the summed dip is regulated kosfvenno to the second and third input; the total dip obtained is adjusted to the koffer unit 4 of the corresponding driver, from the signal of the average level to the first input of the summing unit 4.

transfer coefficient of the controlled attenuator 6. The transfer coefficient of the controlled attenuator 6 is chosen to be 0–1, Herewith, if the gain factor of the narrowband is tuned. A filter amplifier-amplifier 5 is equal to K, then by adjusting the transmission coefficient of the corresponding controlled attenuator 6 in the range from 0 to 2 / K,

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it is possible to obtain a dip of the required depth relative to the average level. The maximum depth relative to the dip will be when the attenuator gain factor is -6 approximately 1 / K. When the magnitude of the transmission coefficient changes from 2 / K to 1, a surge occurs with respect to the average level. Thus, at the output of each driver, the generated signal can have both bursts and dips in the corresponding energy spectrum. With the N-ro shaper, the broadband random signal is fed simultaneously to the inputs of the following reject filter 9 and band pass filter 12. The central frequency of these filters is tuned by harmonic generator 21. Thus, at each moment of time both filters are tuned to the frequency of the harmonic oscillator 21. From the output of the tracking reject filter 9, a broadband random signal without a harmonic component is fed to the input of power amplifier 10. From the output of the following bandpass filter I2, the extracted harmonic is fed to the input of the converter 13 with a voltage code. At the address given at the output of the frequency converter 18-code, information is recorded from the output of the voltage-code converter 13 into the RAM unit 14. In this case, the address from the output of the converter 8 coincides with the value of the frequency of the generator 21 harmonic signal. Both converters are started up by applying signals to their respective inputs from synchronization unit 20.

Thus, in block 14 of RAM, the amplitude-frequency characteristic of the device is recorded. The read address generation unit 19 periodically conducts the end-to-end communication of information from the RAM block 14, From the output of the RAM block 14, the information through the code-time converter 15 is fed to the first input of the second adder 16. As soon as the information at the output of the frequency-18 converter coincides information at the output of the read address generation unit 19, t, e, when the read address coincides with the current frequency value of the harmonic signal generator 21 by the tagging unit 17

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Claims (1)

a mark is generated at the input of the second summitter 16, this signal is necessary to indicate the current position on the frequency axis. The synchronization unit 20 synchronizes the operation of all constituent Parts of the circuit 1-1 for recording and storing the dynamic characteristics of the device. At the same time, it produces line and frame sync pulses arriving at the third input of the second adder 16. Thus, at the output of the second adder 16, a full video signal is obtained, which can be fed to the video amplifier of any video monitoring device. Invention Formula A device for testing products for random vibration, containing a series-connected noise generator, a broadband filter, a first adder, N drivers, each of which includes a summing unit, the output of which is the driver output, and the first driver input, and serially connected narrowband filter amplifier, controlling an attenuator and a phase inverter and a power amplifier, which is required in order to increase the reliability and accuracy of the tests, it is equipped with the following reject The output port is connected to the N-ro output of the driver, and the output is connected to the input of the power amplifier, a harmonic signal generator whose output is connected to the second input of the first adder and the second input of the following rejecting filter, and the recording and storage circuit of the dynamic characteristic of the device, the first input of which is connected with the output of the N-ro shaper, and the second input - with the output of a harmonic signal generator, each of the N drivers is equipped with a phase shifter, the output of which is connected with the third input of the summing block, and the input - with the phase inverter output and the second input of the summing unit, the first input of which is connected with the input of the narrowband filter amplifier, the recording and storage scheme of the dynamic characteristic of the device contains serially connected Next bandpass filter, voltage converter - code, operational memory unit ( OZUH converter code - time in513221076 the interval and the second adder, the sequence of the label, the second input of which TelNo connected block-synchro-connected with the output of the forming unit frequency converter - the code, addresses and the third input of the RAM block, and a tag formation unit and a shape-first input block — with a second block input the read address, the input of which RAM, the first input of the next band pass, is connected to the output of the synchronous filter unit connected to the first input the second input of the converter for recording and storing the dynamic voltage - the code, the third input block device characteristics, the second the formation of the label and the third input input of which is connected with the second input of the second adder, the second input fO of the following bandpass filter and which is associated with the output of the frequency converter unit - code.