SU1027587A2 - Laminated material adhesion strength determination device - Google Patents

Abstract

DEVICE FOR DETERMINING THE STRENGTH OF THE CLUTCH OF LIST MATERIALS BY auth.St. 838536, characterized in that, in order to improve the determination accuracy, it is equipped with an acoustic sensor rigidly connected to one of the gratings, connected to it and between itself with a measuring instrument of the velocity of ultrasonic oscillations and a chamber pressure control unit. IG Sete / iyjfftHCfy MOCfft uttuyyflHffy I I MWtfin le acmertHtiy e l agv9o taj "

Description

The invention relates to the testing of materials, namely, devices for determining the adhesion strength of laminated materials.

A device for determining the adhesion strength of laminated materials is known, comprising a pressure chamber placed therein with the possible movement of a two vacuum suction device, installed coaxially and placed oppositely against the test specimen, and a mechanism for applying a tensile load to the vacuum suction cups and the membrane attached to it in the center there is a disk with a hole; the pressure chamber is made in the form of a hollow cup, from the bottom of which one of the vacuum suckers is rigidly fixed, the other vacuum suction cup is placed on. membrane, and the last closes the glass. In addition, a device for determining the adhesion strength of a layered mat, rial, contains a set of

between the vacuum suction cups there are rigid grids for placement between the tested samples 1.

A disadvantage of this device is the low accuracy of adhesion testing when testing, firstly, the applied mechanical pressure measuring means have a low accuracy class, for example, model MO type gauges — 0.4% accuracy class.

Secondly, due to the specifics of the known device, only the pressure of compressed gas corresponding to the complete destruction of the sample (adhesive layer) is measured during the test, although the process of fracturing — the formation of cracks, local fractures — started at a lower pressure. The process of destruction of the adhesion layer does not occur over the entire area at the same time, but has the character of development in time and in terms of the process and with a fragile, and in a plastic form of destruction, the latter being inherent in almost all polymers.

Local defects, cracks, must be known when testing materials used, for example, in the structures of sealing elements.

The purpose of the invention is to improve the accuracy of determining the adhesion strength of laminated materials.

The goal is achieved by the device for determining the adhesion strength of laminated materials, which contains a pressure chamber, two vacuum suckers placed in it with the possibility of moving, installed coaxially and parallel to the sample under test, and a mechanism for applying a tensile load to the vacuum suckers, as well as a membrane and a disk with a hole fixed on it in the center, the pressure chamber is made in the form of a hollow glass, on the side of one of which one of the vacuum suction cups is rigidly fixed, another suction cup is placed on the membrane, and the latter closes the cup, and also contains rigid grids installed between the suction cups, for placing test samples between them, is equipped with an acoustic sensor rigidly connected to one of the grids

5 between each other by measuring the velocity of propagation of ultrasonic vibrations and the pressure control unit in the chamber.

The drawing shows a schematic diagram of the proposed device. . A device for determining the adhesion strength of laminated materials comprises a pressure chamber 1, two vacuum suction devices 2 and 3 placed therein with the possibility of movement,

 set coaxially. a mechanism 4 for applying a tensile load to a vacuum suction cups 2 and 3, as well as a membrane 5 and a disk 6 with a hole fixed on it in the center. Besides

In addition, the device for determining the adhesion strength of layered materials contains rigid grids 7 and 8 fixed between vacuum suckers 2 and 3, rigidly connected to the grid 7, an acoustic sensor 9 connected to it and between them an ultrasonic vibration propagation meter 10 and a control unit 11 pressure at least 1, as well as shut-off valve 12 and gearbox 13.

 The device works as follows.

Sample 14 is installed between rigid grids 7 and 8, in the planes of vacuum suction cups 2 and 3 create a vacuum, turn on the meter 10 speed of propagation of ultrasonic oscillations (UT) rt increase the pressure of compressed gas in chamber 1

0 pressure, and the required rate of change of pressure is established by the gearbox 13. The gas pressure, acting on the membrane 5 through the vacuum suction 2, transmits the force 5 to the sample 14. At a certain pressure in the sample 14 (in its adhesive layer) a local defect-crack arises, the occurrence of which is accompanied by the appearance in the sample 14 of ultrasonic oscillation, which is perceived by the acoustic sensor 9, is converted by it into an electrical signal, and is recorded by the control unit 11. The control unit 11 outputs

the command to the meter 10 of the speed of the ultrasonic inspection to stop the measurement, and the shut-off valve 12 to close. Meanwhile, the NBJM stops the change in the & laziness in the chamber 1 and as a result, the stretching of the sample 14 stops. The last measured value of the ultrasonic velocity corresponds to the pressure of the compressed gas in chamber 1 ,. leading to the formation of a crack in the adhesive layer of sample 14. To determine the pressure value, the dependence of the velocity of ultrasonic testing in the medium of compressed gas on pressure is used.

When you turn on the meter 10, the rate of propagation of ultrasonic testing acoustic sensor 9 emits impulses of ultrasonic testing of a certain shape and duration.

which are reflected from the parallel surface of the disk 6 and perceived by the acoustic sensor 9. At an echo from the beginning of the destruction, an acoustic signal appears in the product 14, the parameters of which (duration, amplitude or spectrum) differ from the sounding signal. This signal is sensed by the acoustic sensor 9 and, converted into electrical, is received by the control unit 11, after which they are commanded to stop measuring and changing pressure.

Thus, by measuring the rate of propagation of UST using an acoustic sensor, the accuracy of determining the adhesion strength of complex materials is improved.

Claims (1)

DEVICE FOR DETERMINING THE STRENGTH OF COUPLING OF LAYERED MATERIALS according to ed. No. 838536, characterized in that, in order to increase the accuracy of determination, it is equipped with an acoustic sensor rigidly connected to one of the gratings, connected to it and to each other by a speed meter of the propagation of ultrasonic vibrations and a pressure control unit in the chamber. I'm ieMryjrway And mokes