SU979989A1

SU979989A1 - Method of checking cracks in axially symmetrical part material

Info

Publication number: SU979989A1
Application number: SU813302207A
Authority: SU
Inventors: Александр Дмитриевич Шамровский; Анатолий Бениаминович Ройтман; Виктор Афанасьевич Карасев; Владимир Васильевич Омельченко; Николай Николаевич Пруденко
Original assignee: Предприятие П/Я В-2504; Предприятие П/Я А-3438
Priority date: 1981-06-15
Filing date: 1981-06-15
Publication date: 1982-12-07

Description

(54) СПОСОБ КОНТЮЛЯ ТРЕЩИН В МАТЕРИАЛЕ ДЕТАЛЕЙ С ОСЕВОЙ СИ 1МЕТРИЕЙ(54) METHOD OF CONCENTRATION OF CRACKS IN THE MATERIAL OF DETAILS WITH AXIAL SI 1METRY

1one

Изобретение относитс к неразрушающему контролю материалов и может быть использовано дл обнаружени трещин в материале деталей с осевой симметрией.The invention relates to non-destructive testing of materials and can be used to detect cracks in the material of parts with axial symmetry.

Известен способ контрол трещин, заключающийс в том, что в материале возбуждают ультразвуковые импульсы с широким частотным спектром, принимают прошедшие через материал ультразвуковые импульсы, анализируют их спектр, на основании чего суд т о наличии трещин 1 .The known method of controlling cracks is that ultrasonic pulses with a wide frequency spectrum are excited in a material, ultrasonic pulses transmitted through a material are received, their spectrum is analyzed, on the basis of which the presence of cracks is judged 1.

Недостатком его вл етс ограниченна возможность контрол материала деталей сложной теометрии, обусловленна тем, что контролируема область материала определ етс зоной прохождени ультразвукового импульса, распростран ющегос по законам лучевой акустики.Its disadvantage is the limited ability to control the material of parts of complex theometry, due to the fact that the controlled area of the material is determined by the zone of passage of the ultrasonic pulse propagating according to the laws of radial acoustics.

Наиболее близким по технической сущности к изобретению вл етс способ контрол Трещин 20 в материале деталей с осевой симметрией, заключающийс в том, что возбуждают механические резонансные колебани в детали, снимают частотный спектр колебаний и по нему суд т оThe closest in technical essence to the invention is the method of controlling Cracks 20 in the material of parts with axial symmetry, which consists in exciting mechanical resonant oscillations in the part, removing the frequency spectrum of oscillations and judging it

наличии трещин. Механические колебани возбуждают ударной нагрузкой 2.the presence of cracks. Mechanical oscillations excite shock 2.

Недостатком его вл етс мала информативность ко1ггрол , обусловленна тем, что ударной нагрузкой возбуждают одновременно р д форм резонансных колебагтай, часть которых не несет информации о наличии дефектов в материале и затрудн ет анализ спекггра механических колебаний.Its disadvantage is that the information content of a cohgrol is low, due to the fact that a series of forms of resonant oscillations are simultaneously excited by a shock load, some of which do not convey information about the presence of defects in the material and make it difficult to analyze the spectrum of mechanical vibrations.

Целью изобретени вл етс повышение 1шформативности контрол .The aim of the invention is to increase the formatting control.

Поставленна цель в способе контрол трещин в материале деталей с осевой симметрией , заключающемс в том, что возбркдают механические резонансные колебани в детали, снимают частотный спектр колебаний и по нему суд т о наличии треанш, достигаетс за счет того, что возбуждение механических резонансных колебагшй производ т путем приложени в произвольной точке поверхности детали гармонически измен ющейс во времени силы с частотой, равной частоте осесимметричюых колебаний детали.The goal of controlling the cracks in the material of parts with axial symmetry, which is to excite mechanical resonance oscillations in the component, remove the frequency spectrum of oscillations, and judging the presence of cracking, is achieved due to the fact that mechanical resonant oscillations are excited by applying, at an arbitrary point on the part surface, a force harmonically varying in time with a frequency equal to the frequency of the axisymmetric oscillations of the part.

Claims

The method is carried out as follows. 397 In a controlled part, a disk, for example, excites mechanical resonant vibrations. As an exciter of oscillations, a piezoelectric transducer is used to switch on the output of the sound generator and installed in a random part of the surface of the part. The frequency of the generator corresponds to the frequency of axisymmetric oscillations of the part. Mechanical vibrations are received with the help of a piezoelectric transducer-receiver, installed at any point on the surface of the part; c, the output of the converter-receiver signal is fed to the input of the spectrum analyzer. The oscillations of a part without a crack will be harmonic and will have a frequency equal to that of the sound generator. A part with a crack has different stiffness in tension and compression, i.e. it is a substantially non-linear object, therefore, the oscillations in this case will differ from the harmonic ones. Excitation in a part of an axisymmetric form, the resonance of the 1x vibrations allows detection of a crack regardless of its location in the part, since the material of the part is in a state of all-round stretch-compression. Using a spectrum analyzer, the nonlinear distortions of the excited oscillations and by their magnitude are determined by comparing the first and second harmonic amplitudes. Judgment on the presence and size of the crack. Thus, the proposed method allows to increase the information content of the control and its performance due to the fact that the material in the part excites resonant axisymmetric oscillations. Claims The method of controlling cracks in the material of parts with axial symmetry, which consists in exciting mechanical resonance oscillations in the part, removing the frequency spectrum of oscillations. And it is judged about the presence of cracks, and that, in order to increase the information content of the control, the excitation of mechanical resonant coils by the bugs is carried out by applying a force harmonically varying with time at an arbitrary point of the surface of the part with a frequency equal to the frequency of the axisymmetric oscillations of the part. Sources of information taken into account in the examination 1.Sharp R. Methods of nondestructive testing. M., Mir, 1972, p. 62.

2. Schreiber D.S. Ultrasonic flaw detection. M., Metallurgists, 1965, p. 158 165 (prototype).