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No 7 (2025)
Acoustic methods
ACOUSTIC EMISSION AND STRAIN GAUGE CONTROL OF DEFECTS DURING STATIC TESTS OF COMPOSITE SPRING OF AIRCRAFT CHASSIS
Abstract
The article presents the results of tests of the aircraft landing gear support spring made of Toray T800 prepreg and 30 KhGSA steel. The cases of its testing by acoustic emission, ultrasonic methods and strain gauge during the simulation of horizontal aircraft landing and during the simulation of landing with a side impact are considered. During the spring tests, strain gauge was used, tensile, compressive and torsional deformations were studied. The changes in the main informative parameters of acoustic emission signals (MARSE energy parameter, median frequency, structural and two-interval coefficients) were analyzed. The defect type was determined using a modified structural coefficient. This made it possible to increase the speed of information processing, since its decrease corresponded to the matrix destruction, and its increase corresponded to the fiber destruction. The location of acoustic emission signal sources corresponding to the structure area with the greatest relative deformations was obtained. It was noted that when simulating a horizontal landing of an aircraft, after removing the load, residual deformations were observed in the spring material
3-16
Radiation methods
Features of polytetrafluoroethylene application in high-dose dosimetry of accelerated protons by the method of electron paramagnetic resonance
Abstract
EPR — a high-dose dosimetry method for use in monitoring radiation technologies has been tested for a proton beam with an energy of 18 MeV using a domestic brand of polytetrafluoroethylene as a radiation detector and an original EPR spectrometer. It has been shown that the dose range of the EPR signal is limited to 1.5 MGy, after which saturation occurs. Doses exceeding this value can be measured using additional signals in the EPR spectrum. It was found that irradiation of the detectors leads to their gamma radioactivity. The energy of the gamma radiation and the half-life of the source corresponded to the isotope 18F obtained in the nuclear reaction 18O(p, n)18F, which indicated the presence of oxygen in the detector material, which determines their paramagnetic properties
17-25
ELECTRONIC PARAMAGNETIC RESONANCE AND THERMOLUMINESCENCE OF POLYTETRAFLUOROETHYLENE FOR CONTROL OF RADIATION TECHNOLOGIES
Abstract
The possibility of implementing the high-dose dosimetry method based on a combination of electron paramagnetic resonance (EPR) and thermally stimulated luminescence (TL) phenomena was investigated. Domestically produced polytetrafluoroethylene (PTFE) was used as an ionizing radiation detector. Detector samples were irradiated with accelerated electrons with an energy of 10 MeV with doses from 10 to 50 kGy. After irradiation, the intensities of the EPR and TL signals of each detector were measured. The dependence of the EPR signal intensity on the radiation dose was linear. The TL parameters were equal to: maximum temperature Tm = 164 °C, form factor µg = 0,45, frequency factor S = 4,44·1011 s‒1, activation energy E = 1,14 eV. The spectral composition of TL had a wide band with a luminescence maximum of about 425 nm. The dose dependence of the TL output was also linear in the studied dose range. Annealing of EPR and TL signals occurred in the same temperature range, 160—240 °C. The correlation of dose dependences of normalized intensities of EPR and TL signals, the similarity of their temperature ranges of annealing intensities, indicated that the EPR and TL properties of PTFE detectors are associated with changes in the charge states of the same centers
26-33
Electromagnetic methods
APPLICATION OF EDDY CURRENT METHOD OF CONTROL FOR INDICATION OF FATIGUE CHANGES IN AUSTENITIC STEELS WITH MARTENSITE FORMATION
Abstract
The results of cyclic tests of 08X18N10T structural steel are presented. The tests were carried out using the accelerated Location method. The experimental data obtained showed that cyclic deformation of austenitic steel leads to the formation of deformation martensite, as indicated by the results of X-ray phase examination of the sample. The study of the microstructure of steel also indicates structural and phase transformations occurring in steel. The eddy current signal was measured on the test sample before and after the tests. Changes in the phase and amplitude of the eddy current signal occurring after the tests indicate the possibility of using this method to determine the formation of deformation martensite in austenitic steel
34-42
DETERMINATION OF CAVITY SHAPE AND SIZE IN HOMOGENEOUSLY MAGNETIZED MAGNETS WITHIN THE FRAMEWORK OF A TWO-DIMENSIONAL MODEL
Abstract
For extended uniformly magnetized bodies, a practical implementation of a numerical algorithm for solving an integral-differential equation on a function that defines the localization, shape, and size of a cavity in such a magnet based on the measured resulting field outside of it has been investigated. A program in the FORTRAN language that implements the above algorithm has been compiled. As a test and illustrative example of the studied algorithm for a uniformly magnetized cylindrical magnet, the shape, dimensions, and position of a non-coaxial cylindrical cavity in the magnet have been reconstructed
43-58
По материалам XXXV Уральской конференции «Физические методы неразрушающего контроля (Янусовские чтения)»
ESTIMATION OF THE DEFORMATION STABILITY OF THE PHASE COMPOSITION OF AUSTENITIC-FERRITIC CLADDINGS MADE OF POWDER WIRES
Abstract
Magnetic methods are promising for express analysis of the phase composition of austenitic-ferritic steels. During the study of multilayer weld claddings obtained from the developed austenitic-ferritic flux-cored wires, it was necessary to determine the ferrite content in the metal and evaluate the stability of the phase composition under plastic tension. The developed wires allow obtaining a weld metal with deformation stability. The methods used allow determining the proportion of ferrite in the welded state with an accuracy that allows using magnetic methods in production to evaluate the structural composition of finished structures using non-destructive methods
59-64
PRIMARY SENSING ELEMENT OF A DIFFERENTIAL MAGNETIC STRUCTUROSCOPE FOR MEASURING RESIDUAL AUSTENITE IN FERROMAGNETIC STEELS
Abstract
The design of the primary transducer with an H-shaped yoke for a differential magnetic structuroscope (DMS-5) has been optimized for non-destructive testing of residual austenite (RA) content in ferromagnetic steels. Numerical simulation using the finite element method was performed to analyze the magnetic flux distribution in the H-shaped magnetic core, and the optimal gap dimensions for mounting a Hall-effect sensor as the sensing element were determined. Experimental results confirmed a twofold increase in sensitivity of the new transducer design compared to the previous version, enhancing the reliability of non-destructive phase composition analysis in ferromagnetic steels. A linear relationship was established between the output signal of the DMS-5 transducer and RA content in the range of 9—18 % in the tested samples
65-69
SURFACE GEOMETRY RECONSTRUCTION OF CORROSION DEFECTS OF FERROMAGNETIC MATERIALS PRODUCTS BY THE OPTIMIZATION BY LINEAR APPROXIMATION
Abstract
The paper describes a technique developed by the authors for reconstructing the shape and size of surface corrosion defects in products made of ferromagnetic materials based on measured components of the magnetic leakage field strength near the surface of the test object. The optimization problem of approximating the signal of a two-dimensional finite element model to the measured signal was solved by optimization using linear approximation with constraints. A method for approximating the defect shape using basis splines and a physical justification for choosing the reference points of spline interpolation are presented. The described technique was tested in a numerical experiment using a symmetrical defect and an arbitrary-shaped defect as an example
70-73
ULTRASONIC TESTING OF KAPROLON BY ECHO METHOD
Abstract
Ultrasonic control of polymers by the echo method is difficult due to the high attenuation of acoustic waves in the material. To eliminate defects in finished products, enterprises are interested in finding a method for controlling internal defects in kaprolon blanks. The paper proposes flaw detection of kaprolon blanks by the echo method. For this purpose, the velocity of propagation of the longitudinal wave and its attenuation in the caprolon were determined, and the dimensions of the near zone for the transducers A111-2.5-K12, A121-2.5-40 (the angle of entry of the longitudinal wave into the caprolon is 31°) were calculated. An ultrasonic flaw detector with a probe pulse amplitude of 480 V is proposed, which is important for monitoring materials with a high attenuation coefficient. AVG-diagrams have been constructed for defects simulating pores. The calculated data showed convergence with the results of flaw detection of nylon samples with an artificial defect
74-78