SU1564502A1 - Arrangement for determining dynamic pliability of large-scale foundations - Google Patents

Abstract

This invention relates to a vibration measuring technique. The purpose of the invention is to increase productivity by automating the measurement process. The mechanical vibration exciter 1 excites the object under study 2, the oscillations of which are sensed by the measuring sensors 3. The N-channel switch 5 provides channel switching, the signal from its output is processed in the maximum memory unit 7 and transmitted to the recorder 10. The frequency is monitored by frequency sensor 11, the signal from which enters the counter 14 periods. The control unit 9 provides interaction of the device elements. 11 il.

Description

The invention relates to vibration studies and is intended to determine the magnitude of the dynamic compliance of the object under study.

The purpose of the invention is to increase productivity by automating the measurement process.

FIG. 1 shows a general block diagram of the proposed device; in fig. 2 - functional diagram of the N-channel switch; in fig. 3 - switch circuit is functional; in fig. 4 is a block diagram of a control unit; in fig. 5 - driver flow chart of registering devices; in fig. 6 is a block diagram of the recording devices; in fig. 7 is a block diagram of the amplifier amplifier; in fig. 8 is a shaper structure diagram; in fig. 9 is a block diagram of a period counter; in fig. 10 is a flowchart of a device for determining dynamic compliance; in fig. 11 is a flow chart of the operation of the period measurement module and the maximum value.

The device contains a mechanical vibration exciter 1, mounted on the structure under study 2, installed on it at control points N measuring sensors 3, N integrators 4 connected to the outputs of the corresponding measuring sensors 3, connected in series N-channel switch 5, whose inputs are connected to the outputs of integrators 4, a scale amplifier 6, a maximum storage unit 7, an analog-code converter 8, a control unit 9, the second and fourth outputs of which are connected respectively to the control inputs Dami of the maximum memory unit 7 and the N-channel switch 5, and the recorder 10, for example, the recording devices included in the computer, and the frequency channel, made in the form of serially connected frequency sensor 11, filter 12, a shaping amplifier 13 and a period counter 14 , the output of which is connected to the second input of control unit 9, and the second input to the third output of the latter, and the generator

About 4b SP OG

pa 15 reference frequency, connected to the third input of the counter 14 period.

Individual elements of the device can be made, for example, on the basis of standard microcircuits and using elements of computer technology.

The N-channel switch 5 (Fig. 2) is made in the form of a pulse counter 16 and a switch 17 connected to the control unit 9, the information inputs of which are connected to integrators 4, and the output to a scale amplifier 7. The switch 17 can be made on switches 17.1 -17 (M + 1) series 590 on the pyramidal structure.

As the converter 8, the analog-code uses the C5-2109 Electronics module, which has the following characteristics: input signal range from -5 to + 5V, signal conversion time from analog to digital form 200 x.

The control unit 9 can be built on the basis of computer technology. The modules 18-22 of the control unit 9 are interconnected by a highway 23, which includes address-data buses and control buses. Module 18 - a central processor, for example, “Electronics C5-21M, module 19 — random access memory (RAM); Electronics C5-2105; module 21 — digital input-output registers (DAC); Electronics C5-2112; module 22 — recording drivers devices have bidirectional access to the highway. Module 20 is a permanent storage device, it only has access to the trunk. The outputs of the module 21 are connected to the first and second inputs of the block 16, to the inputs of the block 18 and the block 15. The converter 8 analogue code is connected to the highway 23 and has an input to the highway (Fig. 4).

The registrar 10 can be constructed on the basis of the elements associated with the control unit 9. The display drivers for the C5-2106 Electronics 24 and the tape recorder for the C5-1212 25 Electronics have bi-directional output to the highway, and the drivers for the digital printer Electronics C5-2P2 26 and Plotter Electronics C5-2109 27 drivers have an input from highway 23 (FIG. five).

Block 28 is a display, is connected bi-directionally to block 24, block 29 is a tape drive, is connected to block 25 and has a bi-directional highway; Block 30 — a digitizer and block 31 — the plotter are connected to the outputs of blocks 26 and 27, respectively (Fig. 6).

Amplifier-shaper 13 (Fig. 7) can be made in the form of a connected standard amplifier 32 (large-scale amplifier) and shaper 33 (threshold element). As a driver 33, a comparator 34 and Schmckt’s trigger 35 in the input stages and the logical elements NO 37 in the output stages can be used. The input restriction circuit 36 is connected to the output of the Schmitd trigger 35, and the output to the input element HE 37 (Fig. 7 and 8).

The period counter 14 can be made in the form of a counter 38, delay element 39, shaper 40, buffer register 4, AND-NOT element 42. The output of generator 15 is connected to the first input of counter 38, the output of delay element 39 is connected to the second input, and connected to the first input of the buffer register 41, the second input of which is connected to the output of the NAND 42 element and the output of the buffer 41 register connected to the input of the control unit 9. The input of the delay element 39 and the input of the imaging unit 40 are interconnected and connected to the output of the amplifier-imager 13. The output of the imaging unit 40 is connected to the first input of the NANDOM 42, and the second input of the latter is connected to the output of the control unit 9.

The device works as follows.

The exciter i of mechanical oscillations excites oscillations in the object under study 2. Measuring sensors 3 record the speed of the occurring oscillations of the object under study 2, signals from the outputs of integrators 4 give an estimate of the movement of the object under study 2. The N-channel switch performs a sequential switching of the measuring sensors 3. Signal "Reset unit 9 control, the counter 16 is reset to the initial state 5 and the sensor with the number 1 is connected to the switch output. The second input of the counter 16 receives the control th signal that switches the counter 16 to the next state. Output signals counter 16

0 determines the number of the channel connected to the output of the switch 17. The number of bits of the counter is determined from the condition n log2N, where, 1, 2, .... K}; N is the number of sensors; n is the number of bits of the counter.

5 The signal from the scale amplifier 6 is fed to a maximum memory unit 7, where a maximum value of the signal amplitude is extracted, then this value is converted into a digital code and fed to the module 19 of the control unit 9, where it is stored in the data array. By the signal of the control unit 9, the maximum storage unit 8 is zeroed out after each measurement. In the frequency channel, a digital code is formed that is proportional to the oscillation frequency of the object under study 2. From the output of frequency sensor 11, a sinusoidal signal is fed to filter 12, where high-frequency interference is suppressed,

in the communication line and further to the amplifier-shaper 13, which forms a square wave signal. Then a signal arrives at the period counter 14, which counts the number of clock pulses received from the generator 15 of the reference frequency. The start of the counter 38 is performed by the leading edge of the signal coming from the output of the amplifier-amplifier 13. The delay element 39 provides a delay for the signal during the census of information from the counter outputs to the buffer register 41 and is not 120. The counter 38 is reset to the initial position by the falling edge of the signal coming from the output of the amplifier 13. The former 40 is intended to generate the signal "Reset census. This signal, through the AND-NOT element 42, intended to block the signal "Census gate at the time of input of the values of the frequency from the output of the buffer register 41 to the control block 9, is fed to the input" The gate of the census of the buffer register 41.

The block diagram of the device operation (Fig. 10) for determining the dynamic compliance shows the sequence of actions in conducting research. The operation of the device can be divided into three stages. The first stage is the collection of information from sensors. The block diagram of the module for measuring the period and maximum values (Fig. 11) shows the interaction of the control unit with the remaining blocks. At the second stage, the magnitude of the dynamic compliance is calculated for all sensors at the removed excitation frequency values and an array of dynamic compliance values is formed. At the third stage, the output of information to the recording devices 4 is carried out. It is possible to output the graphs of the dynamic compliance dependence as a function of frequency on the graphic display screen and to the plotter. In digital form enters the digital printing device and in the form of arrays on a tape drive.

The device provides the following technical and economic advantages: processing experimental data and outputting information to external devices during dynamic vibration studies; increasing the accuracy of determining the period of the signal when the frequency of the reference oscillator is 15 kHz at the maximum frequency of 60 Hz, the signal period is equal to 18 ms, the counter code 39 corresponding to this period value is 250 pulses and therefore the error in determining the period value is ± 0.4 %), with an increase in the value of the signal period, the value of the error in determining the signal period decreases; improving the accuracy of determining the magnitude of the dynamic compliance (the error in determining the magnitude of the dynamic susceptibility is determined as follows

b biD-bAiP-G-bB.)

where b is the error in determining the dynamic compliance; Bil - the error of the measuring sensor; BDIP - analog-digital error

converter;

BV - control unit error; bid — the measurement sensor error is 5–7% for datas of different types;

 when using a ten-bit ADC and a reference voltage of 5 V, the error of the analog-digital conversion

is defined as

U support0 /

OACP- MO, O%,

where bwu is the error arising in the control unit when calculating the magnitude of the dynamic compliance is associated with a limited bit grid of module 19, in which arithmetic operations are performed on double-byte ones (sixteen-bit ti, the highest

The high byte bit is signed, therefore

BBU 5., 064%

- therefore, 6 (7 + 0.5 + 0.064)% "7.56% ..

The economic effect of the application of the proposed device is determined by reducing the time for conducting dynamic studies. Reduction of time is achieved by automating the process of collecting and processing information from dynamic studies, as well as the possibility of constructing the calculated amplitude-frequency characteristics of an object on recording devices in digital and graphic form.

Claims (1)

Invention Formula A device for determining the dynamic compliance of large-scale foundations containing a mechanical vibration exciter, N measuring sensors. An N-channel amplifier, recorder and connected maximum memory unit and analog-code converter, characterized in that, in order to improve performance, it is equipped with N integrators, the inputs of which are connected to each corresponding measuring sensor control unit, the first input of which is connected to the analog-code converter output, the first output — with the recorder, and the second output — with the control input of the maximum memory unit, and the frequency channel, made in the form of serially connected sensors the cells associated with the mechanical oscillation exciter, filter, amplifier-form and period counter, the output of which is connected to the second input of the control unit, and the second input - to the third output of the last, and the reference frequency generator, whose input is connected to the third input of the counter period, and the M-channel amplifier is made in the form of a connected N-channel switch, the information inputs of which are connected to the outputs of the integrators, and the control input is connected to the fourth output of the control unit, and a large-scale amplifier, It is connected to the maximum memory unit. to 10 "5.1-51 15 1 WtL W / / 7 , k7 FIG. 2 M.N42 n7b 15k28kZO / fff 29 k31 Fiel FIG. 9 Data processing. C Ionian G # 040/70} V ffff00 source data s # / g 0chen1 / e tfaSpfffauSyfo / ff. yc / 77afffftwa va c / rrp / rrir / ffoau / i w / t ST  + not FIG. ten From the beginning j 8MN S & rusnammuty container 6 (/ szh.sp. t / Mepe / tt / e ffffa fdoga, per / shs in OP / N 1 Cfpqc i / e / shadow / rrgx wcrventt / t For / rt / ctr max ygrtes / 7: / 7 + 1 not/