SU1439489A1 - Method of inspecting glued joints of composite articles - Google Patents

Abstract

The invention relates to non-radar control by ultrasonic methods and can be used to control the strength of adhesive joints. The purpose of the invention is to increase the reliability of the control of the strength of an adhesive joint. The product is glued with glue with ferroelectric additives, polarized. The additive domains are electric field. Pulsed ultrasonic vibrations with a frequency spectrum overlapping the resonant frequency of the adhesive bond for all controlled points are excited in the product. The electromagnetic radiation spectrum of the adhesive layer and, additionally, the spectrum of ultrasonic vibrations are recorded, and the spectrum of the normalized transfer function H is obtained ;; a-j / B, .-) / t (A; ./ B.y), where A, .j, B,: are the i-e components of the spectra, co. responsibly, electromagnetic radiation and ultrasonic vibrations for the jth point of control of the product; / n / index normalization. The strength of the adhesive compound is judged by the spectral envelope of the normalized transfer function. 4 nl. "With with

Description

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I The invention relates to non-erecting, it is controlled by ultrasound, and can be used to control the strength of adhesive Mieimvi in various industries of JieHHocTH, where joints of materials and products are used by means of gluing.

The purpose of the invention is to increase the observance of control of the strength of a glued compound of materials and products.

Fig. 1 is a schematic of a set-1CI with which the method is implemented; FIG. 2 shows the spectrum of ultrasonic vibrations emitted by the transducer:); Fig. 3 shows the electromagnetic radiation spectrum of the product in the j-th 1 control point; Fig. 4 shows a bend around a 1 cpect) a of the normalized transfer function.

I The device contains an electric pulse generator 1, the output of which is connected to the transducer 2 via a composite punch 3, the transducer 2 is acoustically connected to the monitored product 4. The composite punch 3 also has an ultrasound transceiver 5, which is connected JK to one of the inputs of switch 6. A. Antenna 7, located at the adhesive Connection of the controlled product 4 is connected to the second input of the switch 6. The output of the switch 6 is connected to the input of the analyzer 8 of the spectrum. Transducer 2, composite punch 3, controlled article 4, J5 ultrasound receivers, antenna 7 are placed on an IB shielding enclosure 9. I The essence of the invention is that the spectral envelope of the normalization transfer function does not depend on parameters not related to adhesive strength. A method is carried out as follows.

The generator 1 (FIG. 1) is excited by: pulsed mechanical oscillations (FIG. 2) in a transducer 2, which emits mechanical oscillations in 4 and through the composite punch 3 to the ultrasound receiver 5. Under the action of mechanical vibrations, the glue joint of the controlled product 4 containing an additive of the pre-polarized {electric field polarized; ferroelectric, radiates electro-: magnetic waves, the spectrum (3) of which

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these are transformed by the resonant physicomechanical properties of the adhesive joint, as well as its uninformative parameters, such as the number of ferroelectric additives, the area of the controlled point, the intensity of ultrasound on the adhesive layer, and the like. Using an antenna 7 connected by a switch 6 to the input of the spectrum analyzer 8, electromagnetic waves are received, the spectrum of which (FIG. 3) is recorded in the analyzer 8 ,. After reading the spectrum of the electromagnetic radiation at the j-th point of the monitored product, the ultrasound receiver 5 is connected to the input of the spectrum analyzer 8 with the switch 6 and the spectrum of the ultrasonic vibrations is recorded (Fig. 2) for the j-th point of the monitored product 4. From the obtained electromagnetic and ultrasonic spectra ie, the components are, respectively, A-; and B, the envelopes of both spectra for the jth point of the product control, for the n components determine the spectrum of the normalized transfer function (Fig. 4)

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g (A, -j / B, .-)

The spectral envelope of the normalized transfer function determines the strength of the adhesive bond.

The envelope of the spectrum of the normalization transfer function does not depend on the concentration of ferroelectric additives in the controlled adhesive layer and on the absorption of mechanical vibrations by the controlled sample, which increases the reliability of the control.

Claims (1)

Invention Formula The method of controlling adhesive joints of composite products, which consists in exciting, at certain points, the controlled product, connected by glue with ferroelectric additives polarized in an electric field, introduced into it, ultrasonic vibrations so that their spectrum covers the resonant frequencies of the adhesive bond of all controlled points of the product, register the spectrum of electromagnetic radiation according to the parameters of which the strength of the adhesive joint is judged, about 1 and 2 with the fact that, with a point, ieni reliability of control, further recorded spectrum of the ultrasonic vibration is determined spectrum , ( the normalized i de fi ned function by the formula M.Aii / SiJ ZlAij / B.-j i "( (n) the 1st configuration of the spectra of the correspondingly electromagnetic radiation and ultrasonic vibrations for the jth control point of the product; normalization index 10 ii the strength of adhesive bonding is judged by the spectral envelope H, -: normalized transfer function, A (mcV) voo 200 (rel. food) 1.0 O 10 20 30 0 SO {(kHz} Put, d ft 25 About iO 20 JO 50 (Hz) 9igL