SU1516842A1 - Apparatus for determining physico-mechanical characteristics of materials - Google Patents

Abstract

The invention relates to a testing technique, in particular to tests for strength. The purpose of the invention is to increase the accuracy by forming a continuous signal corresponding to the creep activation energy. Sample 2 is heated and stretched. From the strain rate sensor 5, the signal goes through a logarithmic converter 11, a differentiating link 12, a dividing converter 13, a differentiating link 18, a threshold unit 19 is fed to the input of the temperature recorder 15 control unit 16, a signal from a temperature sensor 6, a past inverter 14, a differentiating link 17 and then goes to the second input of the dividing converter 13. As the creep activation energy increases at the output of link 18, a signal appears that is proportional to its rate of increase. The threshold device 19 operates and the temperature is recorded on the recorder 15. 2 Il.

Description

one

(21) 4373A37 / 25-28

(22) 01.02.88

(46) 10/23/89. Bup. W 39

(71) Belarusian State Institute of National Economy named after VV Kuyba

(72) M.I. Kushel, I.A. Mochnalnik, V.Yu. Kushel and N.S. Trimak

(53) 620.178 (088.8)

(56) USSR author's certificate

 630553, cl. G 01 N 3/18, 1976.

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(54) DEVICE FOR DETERMINATION OF PHYSICAL AND MECHANICAL CHARACTERISTICS OF MATERIALS

(57) The invention relates to a test technique, in particular to strength tests. The purpose of the invention is to increase the accuracy by forming a continuous signal corresponding to the creep activation energy. Sample 2 is heated: and

f2

g

(L

: l

Ed

eo

four

Yu

.f

t givaets. From the sensor b of the strain rate signal through a logarithmic converter 11. differentiating link 12, dividing converter 13, differentiating link 18, threshold unit 19 is fed to the input of the temperature recorder 15 control unit 16, the signal from the temperature sensor 6 passing the reverse converter 14

The invention relates to a testing technique, in particular to tests for strength.

The purpose of the invention is to increase the accuracy by forming a continuous signal corresponding to the creep activation energy.

FIG. 1 shows a diagram of the device; in fig. 2 - diagram of the temperature sensor.

The device contains a device 1 for creating a load with the grips of sample 2, a heater 3 with an electric heating element 4, a sensor 5 of the strain rate of sample 2, a temperature sensor 6 consisting of | From a thermocouple 7, an adjustable power supply 8 and a summing amplifier 9. Cold junction thermocouple 7 | Placed in vessel 10 with melting ice. The output of the deformation rate sensor 5 is connected to the input of a logarithmic converter 11, the output of which is connected to the input of a differentiating element 12, the output of which is connected to the first input of the functional division converter 13. The code of the temperature sensor 6 is connected to the input of the functional converter 14 of the reciprocal and to the input of the recorder 15 having the control device 16. The output of the functional converter 14 is connected to the input of the differentiating link G /, the code of which is connected to the second output of the functional division converter 13, the output of which is connected through the differentiating signal 18 and the threshold device 19 (Schmitt trigger) to the temperature recorder 15. The latter registers the absolute temperature. Temperature measurement in degrees Celsius is possible.

the magnitude, the differentiating link 17, then goes to the second input of the converter 13 division. As the creep activation energy increases at the output of link 18, a signal appears that is proportional to its rate of increase. The threshold device 19 operates and the temperature is recorded on the recorder 15. 2 Il.

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The device works as follows.

Sample 2 is secured in a load application device 1. Sensor 5 of the strain rate causes a signal proportional to the rate of the extension of sample V, which depends on the temperature T at which the measurement is taken:

V v (t).

The signal is proportional to the temperature T, and the sensor 6, the emf of the thermocouple 7, when its cold junction is in the vessel 10, is proportional to the hot temperature t C and fed to the first input of summing amplifier 9, the output of which is proportional to the absolute the temperature of the object T. When the voltage is applied to the terminals of the heating element 4, the absolute temperature of the sample T starts to rise. At the same time, it creeps, i.e. strain rate increases. The connection between them is as follows:

V (-Eft / RT)

where K is the activation energy of creep;

R - universal gas constant.

The sensor signal b in the logarithmic converter 11 is converted, and in the link 12 is differentiated in time o. As a result, there is a signal

X, proportional.

d 1 /

The signal of the absolute temperature sensor 6, successively passing through the function of the inverse transducer 14 of the inverse value and differentiating element 17, is converted into a signal Y,

dO / T)

d

The X and Y signal in the dividing function converter 13 undergoes a X / Y division.

As a result, the output of the converter 13 is a signal corresponding to the activation energy

, d (lnV) d1 d (lnV); t / jf - - d (T7f) By definition of E /

-R

d (lnV) d (T7f)

As long as the activation energy of creep does not change, its derivative remains equal to zero: at E const

-L 0.

d I

At the same time, there is no signal at the output of differentiating Even 18, Schdatt's trigger is closed, control device 16 is de-energized. The temperature sensor 6 is not fixed because the control device 16 is not activated.

When the limit temperature is reached, the creep activation energy begins to increase. At the output of differentiating link 18, a signal appears, the value of which is proportional to the rate of increase in energy a: ktivatsii Unit. At its level, which corresponds to a logical one, the Schmitt trigger will open and a signal will be received at block 16. As a result, the registrar

16842

will fix the temperature. In this case, block 16 can either issue a command to turn on, for example, a digital printing device, or give a command to turn off, for example, self-pinging on the potentiometer. At the same time to the output of the threshold unit 19 can be connected to the switch of the heating element 4.

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Claims (1)

Invention Formula A device for determining the physicomechanical characteristics of materials containing a heater, a device for creating a load with specimen grips, a strain rate sensor and a temperature sensor, which is concerned with the aim of increasing the accuracy by generating a continuous signal corresponding to the creep activation energy, it is equipped with a series-connected deformation rate sensor with a logarithmic converter, the first differentiator, a functional converter EIW second differentiating element, a threshold unit, control unit and the registrar temperature and successively soedig nennmi with temperature sensor functional converter inverse value and the third differentsiruschim link, whose output is coupled to the second input of the functional transducer division, and temperature sensor output is coupled to the second input temperature recorder.