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V7: Summary report NEMENUS for SÚJB
Štefan, Jan ; Joch, Jaroslav ; Převorovský, Zdeněk ; Gabriel, Dušan ; Krofta, Josef ; Chlada, Milan ; Kober, Jan ; Masák, Jan ; Kunz, J. ; Ashhab, B.
This is the final report of project TAČR TK01030108: Innovative methods for nuclear plant safety evaluation based on SHM technologies and related procedures - NEMENUS (NEw MEthods for NUclear Safety). In this report, the most important project results and outputs are presented, as well as a summary of its contributions with respect to long-term technological horizons.
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V6: Report on functional sample NEMENUS
Štefan, Jan ; Joch, Jaroslav ; Převorovský, Zdeněk ; Gabriel, Dušan ; Krofta, Josef ; Chlada, Milan ; Kober, Jan ; Masák, Jan ; Materna, A. ; Kovářík, O. ; Čech, J.
This research report is an integral part of mandatory output V6: FUNCTIONAL SPECIMEN of project TAČR TK01030108: Innovative methods for nuclear plant safety evaluation based on SHM technologies and related procedures - NEMENUS (NEw MEthods for NUclear Safety). The report presents full technical description of the elaborated representative functional specimen (the representative SHM model) and the description of a four-year experimental program.
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Research Report: Representative SHM Model
Převorovský, Zdeněk ; Joch, Jaroslav ; Kober, Jan ; Krofta, Josef ; Chlada, Milan ; Štefan, Jan ; Kunz, J. ; Ashhab, B.
The Research Report is output of the project NEMENUS dealing with methodology development of Structural Health Monitoring (SHM) for nuclear power plant components. SHM incorporates advanced methods for evaluation of structural operating safety. It consists in continuous monitoring of critical structure parts by advanced Nondestructive Testing (NDT) methods enabling assessment of their residual lifetime. The literature search part of this report comprises different aspects of the main problems including history of SHM systems applications at civil and mechanical structures, and also the newest SHM trends in nuclear and non-nuclear industry. The material damage mechanisms in nuclear power plant environment are also discussed in the report. At the report end there is indicated practical realization of the project results and SHM verification on a model structure.
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Monitoring techniques for special alloys from some medical prostheses.
Savin, A. ; Vizureanu, P. ; Převorovský, Zdeněk ; Steigmann, R. ; Chlada, Milan ; Krofta, Josef ; Baltatu, M.S. ; Craus, M. L. ; Nový, F.
The paper presents complementary methods for noninvasive evaluation of an exotic class of alloys possible to be used in medical prosthetics. The interest in this study is the analysis of Ti alloys with different concentration of Mo and Si, in order to make the elastic modulus and Poisson ratio reach values appropriate with human bones. The both methods, acoustic emission and resonant ultrasound spectroscopy are proposed as complementary methods for nondestructive evaluation of entire sample volume.
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Nonlinear ultrasonic porosimetry of 3D printed metallic parts
Převorovský, Zdeněk ; Krofta, Josef ; Kober, Jan ; Kirschner, A.
Additive manufacturing process optimization requires a feedback from nondestructive testing (NDT) and evaluation. In this contribution are discussed NDT results obtained by nonlinear elastic wave spectroscopy methods to classify presence of defects in Ti-6Al-4V prismatic samples fabricated by electron beam printer. Quantitative calibration of porosity was realized by metallography. The best porosity classification results were obtained by nonlinear wave modulation spectroscopy with chirp excitation and by ESAM (Excitation Symmetry Analysis).
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Localization of continuous acoustic emission sources using time reversal procedure
Převorovský, Zdeněk ; Krofta, Josef ; Kober, Jan ; Chlada, Milan
A new solution with the help of Time Reversal (TR) signal processing approach is suggested in this paper. It allows planar location of burst AE sources under high background noise using only one transducer, and continuous AE sources with two transducers, both under high background noise from other sources. TR procedure was in this approach applied to long random noise signals for the first time. Suggested method was verified by means of experimentally simulated AE sources on a steel plate and tube. Source location results certified high robustness of suggested approach. Certain disadvantage of the new method is requirement of detailed scanning of region around a presumed source. Scanning may be eliminated if we use numerical simulations with TR signals put into a computer model of the structure. Localization accuracy of suggested procedure (approx. 1 mm) is better than the wavelength and transducers aperture.
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NDT in additive manufacturing of metals
Převorovský, Zdeněk ; Krofta, Josef ; Kober, Jan
In this study we tested possibilities of nonlinear elastic wave spectroscopy (NEWS) methods to classify two types of artificially created defects in Ti-6Al-4V prismatic samples fabricated by Electron Beam Melting (EBM) system. Two series of samples with variable internal defects were tested: samples with central circular defects (missing material gaps), and samples with gradually growing stochastic porosity. Each group of samples contained also fully compact sample for a comparison. Five ultrasonic NEWS procedures were used to classify defects variability. Relatively simple experimental facility with two piezoelectric transducers allows interrogate samples and record their response. The best results, documented in this paper, were obtained by two modifications of NWMS procedure. Results of NEWS tests indicate that selected NEWS procedures can be used also for online AM monitoring.
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Verification of diagnostic device using NEWS methods
Chlada, Milan ; Krofta, Josef ; Kober, Jan
Within the framework of the project „Verification of diagnostic device using NEWS methods“ supported by SIC, several calibration tests of newly developed apparatus for non-destructive testing of materials by NEWS (Non-linear Elastic Wave Spectroscopy) methods were realized. The report summarizes the results of characteristics measuring for case of particular components of the device and the demonstration tests of defect detection in selected structure parts.
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The System for Automatic Location of Impacts
Chlada, Milan ; Kober, Jan ; Převorovský, Zdeněk ; Krofta, Josef
The report deals with the automatic target system for on-line evaluation of shooting precision based on acoustic emission (AE) method, known from the field of non-destructive testing as an approach for location of material defects. Since the bullet stroke on a steel plate can be considered as an AE source, the method can be included in a target system consisting of impact plate, AE sensors and AE measuring system with implemented advanced location algorithms. Whole system can be sized and matched to specific customer needs. At the end of the report, the real demonstration of the system is shown.
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