Method for non-destructive inspection for degree of damage of metal containers
FIELD: nuclear energy.
SUBSTANCE: invention can be used for a nondestructive inspection for the degree of damage of metal containers with spent nuclear fuel. Core of the invention is that onto the surface of the container installed are ultrasound radiators and signal receivers in equal proportions, which generate rectangular pulses with appropriate width, length and frequency. Measured is initial speed of US signals propagation in a non-uniform medium to calculate the value of sensors displacement along the container wall and across it. Matrix of signals coming from all the receivers is formed. With the help of the matrix a scan sector is created with the ultrasonic wave travel time from each sensor to each point of the volume with due allowance for conversion of ultrasonic waves at their reflection and refraction at the media interfaces. Obtained signals by a computer program are formed into sector images. Then the sector images are formed into a composite V-image, basing on which a volume model of the defect from different measurement points is created. As per the change of the volume image over time the container wall degradation is determined.
EFFECT: technical result is creation of a portable method of measuring the degree of damage of metal containers with the inspection results quality exceeding refinement achieved by radiographic inspection.
1 cl, 2 tbl, 9 dwg
SUBSTANCE: method includes scanning flat articles with an ultrasonic transducer in two mutually perpendicular directions: back-and-forth across and discrete rectilinear along the inspected article. A thick-walled inspected article is scanned with multiple ultrasonic transducers mounted in a single acoustic unit in one row equidistant from each other and fitted with separate clamps to the surface of the inspected article which provide them with three degrees of freedom when scanning, wherein scanning of the acoustic unit along the inspected article is carried out with alternating odd short and even long steps, after which the actual longitudinal coordinates of the detected defects are determined as the sum of current coordinates of the first transducer and the distance between the centres of the first transducer and the transducer which detected the defect.
EFFECT: more reliable inspection, avoiding a dead inspection zone, rejection of flat articles and missing defects.
SUBSTANCE: beam of ultrasound oscillations is irradiated to piezoelectric transducer prism. Longitudinal oscillations reflected from object contact surface by extra piezo-plate. This method allows measurement of time-shift of reflected oscillations is measured to define thereof the layer depth.
EFFECT: possibility to measure contact layer depth to add to validity of ultrasound control.
SUBSTANCE: method includes generating, in the wall of the connecting pipe, perturbation action using an ultrasonic radiator mounted on the outer surface of the connecting pipe, and measuring the input signal parameter value by measuring the amplitude and determining, on the A-scan line, the location of the reflected ultrasonic pulse from the liquid crystal screen of an ultrasonic flaw detector. The method further includes determining the length of the path of the reflected echo signal from the end of the connecting pipe to the point of installation of the radiator by moving the ultrasonic radiator along the connecting pipe on the outer wall to obtain a maximum echo signal, followed by calculating the length of the extending part of the connecting pipe using a certain formula.
EFFECT: high accuracy and simple method of determining the length of the connecting pipe of T-joint steel pipes.
SUBSTANCE: analysis of pipeline by proposed method uses piezoelectric converters to record signals reflected from inner or outer wall of the pipeline that exceed program-defined threshold. Reflected signals are selected by maximum amplitude referenced to time of arrival from radiated pulse. Then, at least four signals are selected by maximum amplitudes and recorded as magnitudes of time of radiated pulse and amplitude. Defined are boundaries of the beginning of wall depth variation from so-called "defect boundary uncertainty zone". Depending on signal structure in said zone correction magnitude is calculated to correct the signals of indent and pipe wall depth.
EFFECT: determination of said boundaries with arbitrary location of planes to perpendicular of acoustic axis of piezoelectric converter.
5 cl, 7 dwg
SUBSTANCE: sensitivity of NDT equipment is adjusted in the manual mode, it is checked in the automatic mode, then placed on an object table of the unit of inspected product, it is centred, the ultrasonic converter is mounted on the product surface in the zone of inspection beginning, switching of automatic verification mode, scanning by the product surface converter along the spiral, input - reception of acoustic oscillations by a contact and slot method using converters with a local bathtube in a product and in references at adjustment by them and check of the equipment sensitivity, and also fixation of existence or absence of defects. For inspection of dome-shaped products with spherical surfaces, the converter is moved along a bow-shaped trajectory, the converter scans the product surface along a convex spiral of Archimedes, and at detection of defects their angular coordinates are read out in two mutual and perpendicular directions.
EFFECT: possibility of automated ultrasonic quality control of dome-shaped products with spherical surfaces.
SUBSTANCE: dynamic calibration of USD is performed, USD comprises the row unit of electro-acoustic converters, first of which is ultrasonic radiation generator, and the subsequent converter or converters are ultrasonic radiation receivers, and the threshold level of the detector actuation is pre-set on the basis of the current value of amplitude of the reference signal radiated inversely with reference to the main probing signal and representing by itself a residual ultrasonic generator radiation at the current step or compulsory ultrasonic generator radiation at the additional step.
EFFECT: improvement of accuracy of setting of threshold level of ultrasonic detector actuation during examination.
3 cl, 17 dwg
FIELD: measurement equipment.
SUBSTANCE: invention describes a method of excitation of acoustic oscillations using electromagnetic and acoustic (EMA) method with the use of the phenomenon of EMA-resonance and can be used in nondestructive examination, in particular, of low-conducting materials. In the top layer of the tested product the vortex currents are generated and occurrence and distribution of acoustic oscillations is initiated, and the exciting field frequency is selected from the conditions of equality of lengths of waves of electromagnetic and acoustic fields, and the phase is adjusted until coincidence of spatial distribution of the driving force with strains of a crystal lattice.
EFFECT: improvement of efficiency of excitation of acoustic oscillations by electromagnetic and acoustic method.
2 cl, 3 dwg
SUBSTANCE: two electro acoustic transducers are mounted at rail rolling surface. Said transducers are directed to opposite rail heat inner surfaces to probe rail head. For this, said transducers are displaced along the rail to emit probing signals and to receive reflected ultrasound signals. The latter are analyzed in selected time window to conclude on availability and degree of flaw development. Position and direction of transducer radiation are selected to make ultrasound probing signals reflected from rail head surfaces directed to working and nonworking covings. Time window of signal reception from micro fractures at rail head working coving is selected about the expected time of reception to signals reflected from rail head coving whereat transducer reception sensitivity is increased to the level of the beginning of reception of rail metal structural noises. Analysis of reflected ultrasound signals and conclusion about availability and development of micro fractures are performed on the basis of comparison of reflected signals received by said transducers from working and nonworking covings.
EFFECT: possibility of detection and estimation of micro fractures development.
SUBSTANCE: scope of application: for laser-ultrasound quality control of the soldered joints. The essence of the invention is that using the pulse laser the optical pulses are generated, they are converted in the acoustic signal - series of ultrasound pulses creating the sounding ultrasound beam, the studied object is subjected to this beam action, the piezoreceiver receives the signals reflected from the studied object, they are analyzed, and based on the analysis results the object internal defects are estimated, at that the specified acoustic signal is formed as aperiodic sequence of ultrasound pulses with width from 5 to 20 ns with creation of the sounding ultrasound beam with diameter from 0.6 to 1.0 mm.
EFFECT: possibility of quality control of the soldered joints of thin cell double-wall steelworks.
SUBSTANCE: for non-destructive methods of control of internal structures of objects. The substance of the invention consists in the fact that a laser ultrasonic flaw detector comprises a pulse laser, connected via optic fibre with an optic-fibre converter made in the form of a single unit arranged on the investigated object, and comprising a plate of the optic-fibre generator, and also a piezoreceiver connected via an amplifier with an analogue-digital converter connected to a computer, at the same time the optic-acoustic generator and the piezoreceiver are spatially distanced and placed on inclined acoustic lines that contact with investigated material, and the laser, analogue-digital converter and power supply unit are in a separate body.
EFFECT: expansion of functional capabilities of a device due to usage of different types of acoustic waves.
FIELD: non-destructive control means.
SUBSTANCE: device has body made of organic glass, in which two apertures are made, into which active element in spring-loaded body and grounding electrode, also spring loaded, are respectively mounted. Current-conductive wires of coaxial cable are connected to active element and grounding cable. At upper portion sensor is closed by lid, direction of polarization of piezoceramics of active element of ultrasound converter is directed at angle of 70°-80° to lower surface of active element. In planes, parallel to lower surface of active elements, direction of polarization of piezoceramics of active element is at angle 35°-55° to longitudinal axis of active elements. Cable is connected to generator of ultrasound impulses.
EFFECT: higher precision.
FIELD: non-destructive control.
SUBSTANCE: method includes forming forced mechanical oscillations in first point, changing effect frequency until appearance of resonance oscillations in device. In second point parameters of these oscillations are measured, as which oscillation amplitudes are recorded with effect frequency and with double effect frequency, while resonance is determined on basis of maximum oscillations amplitude with double effect frequency. Then relation of square oscillations amplitude with effect frequency to oscillations amplitude with double effect frequency is determined. Then oscillations are excited in second point, and recording of parameters is performed in second point, by analogical method for this case second value of relation is determined and on basis of average value of two relations flaw level of product is estimated.
EFFECT: higher trustworthiness.
FIELD: nondestructive testing.
SUBSTANCE: device can be used for measuring thickness of items made of aluminum and steel. Acoustical-electromagnet transducer intended for the acoustical device for ultrasonic testing of different materials has biasing system and probing pulse oscillator. Oscillator has active element, capacitor and inductance coil. Winding of inductance coil is made of at least two independent departments having like direction of reel. Device is additionally provided with active elements and capacitors, which form independent oscillators with any department of winding. Active elements, for example, transistors are made for connecting synchronously or with phase shift.
EFFECT: improved precision of measurement; reduced consumed power; widened operational capabilities.
2 cl, 1 dwg
FIELD: nondestructive testing; ultrasonic testing.
SUBSTANCE: method can be used for determining shapes of defects and spatial position of such defects as cavities, slag inclusions as well as for measurement of thickness of tested objects with complex profile. Ultrasonic oscillations are excited in tested object by piezoelectric converter having wide directional pattern which results to reduction in distortions of acoustic image induced by spread of acoustic wave propagation. When receiving reflected oscillations the receiving piezoelectric converter is disposed at different points on surface of tested object. Then object is divided to local parts, which are judged as local concentrated reflecting element. Reflected signal after being received by any position of receiving piezoelectric converter from any local area have to be shifted in time for value being equal to time of propagation of reflected wave from local area till corresponding position of receiving piezoelectric converter. Then time-shifted signals are summed correspondingly for any local area. The procedures described before repeat for two or more frequency versions for each of which frequencies of acoustic waves being used at ultrasonic test are different. For any frequency version M preliminary images are formed in form of values of amplitudes of sum signals, which correspond to different local areas of tested volume and are defined for different assumed values of speed of wave propagation in material M. Then all pairs of M preliminary images are compared pairwise which images are specified for any frequency version at similar values of speed of propagation. Pair of images is chosen from all the pairs having less differences than others and final acoustic image of tested object is formed in form of half-sum of latter images.
EFFECT: improved precision.
2 cl, 3 dwg
FIELD: nondestructive testing; ultrasonic testing.
SUBSTANCE: to detect signal reflected from a defect and to estimate location of defect, information properties of signal are analyzed at output of receiver of flaw detector by means of large-scale wavelet testing methodology which allows to find small in amplitude local changes of signal including "dead zone" of flaw detector. Wavelet-spectrograms of reference signal are formed at output of receiving path of flaw detector which corresponds to case when defect is absent in tested sample. When defect of unknown quality appears in tested material, wavelet-spectrogram of controlled signal at output of receiving path of flaw detector Wf (a, t) and its ai cross-section at different scales of ai would differ from wavelet-spectrogram of reference signal which is adequate to detection of signal reflected from defect. To find the location of defect the wavelet-spectrograms of shortened realizations of reference and controlled signals are formed sequentially for time of τy. Shortening of signals is performed from the end of sequence for the same value till wavelet-spectrograms of shortened realizations of reference and controlled signals as well as their cross-sections become practically equal at different scales of ai. Length of those shortened realizations of reference and controlled signals has to be evaluation of defect location.
EFFECT: improved precision.
2 cl, 11 dwg
FIELD: investigating or analyzing materials.
SUBSTANCE: method comprises generating pulses of free flexible vibrations in the part of the pipeline to be tested and changing loading subsequently in all local zones of the part. Two measurements of the flexible vibration frequency are performed for each local zone for various acoustic loadings in the immediate vicinity of the local zone. The presence of defects and their location can be judged from the presence and location of zones characterized by the step variations of the results of the first and second measurements.
EFFECT: expanded functional capability and sensitivity of the method.
FIELD: ultrasound control of materials.
SUBSTANCE: device has body, substrate, lid, concentrators, constant magnets and inductive coils. It is also provided with at least two couples of ferromagnetic concentrators, placed in parallel to each other, in each pair concentrators are mounted symmetrically to each other relatively to at least one flat constant magnet, made, for example, of connection Ne-Fe-B and enveloped by electromagnetic coil, connected to source of pulse constant current. Concentrators are made in form of cylindrical ferromagnetic rods and fixed in on substrate of non-magnetic material with possible vertical displacements in bushings of ferromagnetic material, pressed to opposite sides of constant magnet.
EFFECT: higher reliability and efficiency.
FIELD: non-destructive control.
SUBSTANCE: device has inductive coils, body, concentrators, substrate, magnetic duct in form of hollow cylinder, cover and air ducts system. Concentrators body is made of magnetic material, is fixed at hollow cylinder by two joints and a frame. One joint connects body of concentrators to frame, another joint connects frame to hollow cylinder. Body in central portion is made in form of cylinder with apertures for concentrators and provided with plate of non-magnetic material, to which substrate is connected. On the side of object of control, body of concentrators has slants, and on opposite side ends with cone with aperture for feeding compressed air through channels, made in body and in substrate.
EFFECT: simplified construction, higher reliability, higher efficiency.
FIELD: non-destruction testing processes, possibly ultrasonic testing of cylindrical articles such as railway road wheels, bands, drums, pulleys and other products.
SUBSTANCE: method comprises steps of irradiating surface ultrasonic waves across cylindrical surface of article and receiving echo-signals caused by flaws; extracting signal passing around article n times; regulating amplification degree of received signals while sustaining constant amplitude of extracted signal; setting threshold levels for time intervals between probing signal and signal that passes around article one time, at time intervals between one time passing and two times passing signals, between two times and three times passing signals; evaluating flaw occurrence according to echo-signal exceeding threshold levels. Said threshold levels are set while taking into account features of distributing ultrasonic oscillations at their circulation in material of article. Number of n extracted signal is selected according to construction of cylindrical article and conditions of propagation of ultrasonic oscillation in it.
EFFECT: enhanced reliability and efficiency of testing articles.
FIELD: non-destruction flaw detection, namely evaluation of damages of single-axis constructions with use of free elastic oscillations.
SUBSTANCE: apparatus includes unit for fixing local zones of constructions in the form of bracket that may move along construction and that may be rigidly secured to ends of local zone; elastic oscillation detector. Elastic ferromagnetic plate is placed between bracket and construction. Lengthwise axis of said plate is normal relative to axis of construction. One end of plate is fastened by cantilever fashion on bracket; its other end being in free elastic contact with construction may be moved relative to it. Elastic oscillation detector is in the form of cylindrical reel secured to bracket and embracing concentrically said ferromagnetic plate.
EFFECT: enhanced responsibility and efficiency of testing, lowered risk of construction damage during testing process.