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Vol 53, No 12 (2017)
- Year: 2017
- Articles: 6
- URL: https://journal-vniispk.ru/1061-8309/issue/view/11318
Acoustic Methods
Applying an Ultrasonic Lamb Wave Based Rechnique to Testing the Condition of V96ts3T12 Aluminum Alloy
Abstract
Possibilities offered by an ultrasonic inspection technique that is based on using Lamb waves for monitoring the state of metal materials under static and cyclic loading have been studied. Dogbone V96ts3T12-aluminum-alloy specimens of the following two types have been used for research: initial material and a sample with a weld at the working zone center. The digital-image correlation method has been used as an additional source of information. Based on the tests, dependences of various informative parameters of acoustic vibrations on the applied load (for static tests) and running time (for cyclic tests) have been obtained. These dependences have been further supplemented with the results of calculation of deformation fields. The data gathered indicate sensitivity of the proposed ultrasonic inspection technique to various (elastic and plastic) deformation processes and allow one to monitor the growth of cracks under cyclic tests. Further development of the method assumes its examination from the viewpoint of embedded testing systems (the Structural Health Monitoring concept).
817-829
On the Possibility of Using Ultrasonic Surface and Head Waves in Nondestructive Quality Checks of Additive Manufactured Products
Abstract
The possibilities and limitations of applying head and surface waves to ultrasonic inspection of articles manufactured by selective laser alloying are considered. The optimum angles have been determined for the generation of head and surface waves in a product made of the domestic EP648 powder. The peculiarities of revealing crack-like flaws by the ultrasonic echo method are demonstrated.
830-838
Examination of Reflection from a Disk using Linear Phased Array Probe in Immersion Mode
Abstract
Numerical model has been developed in this study based on Huygens and Fermat principles applied to calculate the interference of signals emitted by all elements in an active group of a phased array probe for one focus law. Calculations are presented as ultrasonic field emitted by point source substituting for the active group of the phased array probe, and located in its center. Kirchhoff approximation model is also used to present the field emitted by each rectangular element in the active group, thus accounting for the element length influence on the field emitted by a phased array probe. Findings are shown of ultrasonic field transmitted and received by the same active group of linear phased array probe, after its reflection from infinite plane and disk reflector. Results are illustrated in amplitude–distance type nomographic charts for various reflector diameters (DGS) for one focal law. The theoretical model developed has been validated by experimental results of immersion ultrasonic testings.
839-849
Powerful Sources for High Frequency Electromagnetic Transducers for Measurement, Monitoring and Diagnostics
Abstract
Conceptual provisions for the construction of miniaturized variable parameter of high-power high-frequency broadband radio pulse amplifiers have been developed: filling frequency, duration, significant peak current and peak voltage. A circuit-based solution is proposed for constructing high-frequency radio signal of high-power amplifiers, whose frequency varies in the interval 0.1 … 20 MHz, the time duration is 1 … 10 periods of pulse filling frequency, with an output current that reaches 200 A and voltage up to 4 kV. The use of the developed powerful amplifier will allow creating and improving the instruments for ultrasonic quality control of products by electromagnetic-acoustic transducers in industry and electromagnetic transducers in medical devices using the effect of nuclear magnetic resonance, electron paramagnetic resonance, and also in measuring devices.
850-855
Magnetic Methods
Hardware for Inspection of Ferromagnetic Low Coercive-Force Articles
Abstract
Hardware that uses plug-in detectors and allows one to measure coercive force in the range of few to several hundred A/m in industrial products of different shapes is presented. The operating principle is based on a functional relationship between the tangential component of the magnetic field close to the surface of a residually magnetized article and the coercive force of the article material as well as a connection between the gradient of the field of a magnetic pole formed at the article surface after local magnetization and the coercive force.
856-861
Magnetic Flux Leakage Signal Inversion Based on Improved Efficient Population Utilization Strategy for Particle Swarm Optimization
Abstract
In this paper, an improved efficient population utilization strategy for particle swarm optimization (IEPUS-PSO) for high dimension problem is proposed to estimate defect profile from magnetic flux leakage (MFL) signals. In the IEPUS-PSO, a mutation probability is proposed to distinguish local version and global version in particle change model and a self-adapted mutation operator, which is used to update the particles’ positions randomly, is introduced into EPUS-PSO. The IEPUS-PSO- based inversing technique is used to estimate the defect profiles. The estimated defect profiles of simulation signals demonstrate that the inversing technique based on the IEPUS-PSO outperforms the one based on EPUS-PSO. The results estimated from real MFL signals by the IEPUS-PSO-based inversing technique indicate that the algorithm is capable of decreasing the computation time. The results show that the IEPUS-PSO-based inversing technique could improve the reconstruction precision by two orders of magnitude for the MFL simulation signals, and for the real MFL signals, the computation time is reduced by about 30% nearly under the same reconstruction precision.
862-873