Results 1 - 10 of 168
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[en] The paper presents the concept of a highly efficient system for excitation and reception of Lamb waves in ferromagnets. Methods for creating large polarizing fields allowing to increase the efficiency of generation and reception of Lamb waves in ferromagnets and the principles of unidirectional electromagnetic-acoustic transducers are proposed. The results obtained in this work can be used in the development of devices for non-destructive testing of the long ferromagnetic objects. (paper)
[en] Department of Electrical Engineering and Nondestructive Testing, NRU “MPEI”, has been working on development Electronic Learning Resources (ELRs) in course Electrical Engineering and Electronics for several years. This work have been focused on education intensification and effectiveness while training bachelors in nonelectrical specializations including students from Thermal and Atomic Power Engineering Institute. The developed ELRs are united in a tutorial module consisting of three parts (Electrical Circuits, Electrical Machines, Basics of Electronics): electronic textbook and workbook (ETW); virtual laboratory sessions (VLS); training sessions (ETS); personal tasks (PT); testing system that contains electronic tests in all course subjects and built-in verification of a student’s work results in ETW, VLS, ETS, PT. The report presents samples of different ELRs in html format and MathCAD, MatLAB Simulink applications, copyrighted programs in Java2, Delphi, VB6, C++. The report also contains the experience description, advantages and disadvantages of the new technologies. It is mentioned that ELRs provide new opportunities in course studying. (paper)
[en] As a non-contacted non-destructive testing equipment, the bridge deflection measurement instrument based on the principle of photo-electric imaging has the characteristics of high measurement precision, strong dynamic and static deflection observation ability and long observation range, and has a vast application prospect in the field of bridge structural health monitoring. The photoelectronic imaging bridge deflection instrument obtains the deflection measurement result based on the target image, and the image quality is an important influential factor of the measuring accuracy. Illuminance intensity is an important factor affecting the image quality, and will have an important influence on deflection measurement in different weather conditions and different time periods. This paper studies the effect of the different illuminance intensity conditions on the accuracy of the photoelectronic imaging bridge deflection instrument, then a correction method of deflection measurement accuracy based on illuminance intensity measurement is proposed, and the brightness balance correction to the experimental pictures is refined. (paper)
[en] This paper shows an ability to find internal defects in construction of polymer composite material using THz imaging. Using THz vision system resulted in an example of finding internal non-impregnated area in fiberglass
[en] The paper presents the research findings obtained as a result of the ultrasonic nondestructive testing of flaw detection in one-sided access confined concrete. The ultrasonic nondestructive testing is applied to detect the size and location of internal defects in confined concrete that allows the accurate taking cores and their mechanical testing. Tomographic images of the scanned internal structure are given herein as well as the results of compressive strength testing of cores taken from defective portions of the concrete one-sided access construction. (paper)
[en] This study proposes a damage indicator based on mode shape curvature to localize free-spanning damage of submarine pipeline systems. The feasibility of curvatures of low-frequency mode shapes for localizing free-spanning damage of pipeline systems is discussed, and damage indicators based on mode shape curvatures are proposed. The efficacy of the proposed damage indicators is demonstrated by numerical simulations of dynamic responses of a submarine pipeline under ambient conditions with considering the real subsea environment. The proposed approach is simple, which does not require baseline data, and thus is promising in practical applications.
[en] Lockin-thermography has become a valuable tool for non-destructive testing (NDE) of materials since it provides in a short time phase images of hidden defects. However, besides finding defects it is important to derive more information to characterise them. We present an innovative way to combine phase images obtained at different lockin-frequencies by using scatter plots. Besides defect depths this method of data fusion allows for feature extraction like thermal wave reflection coefficient, local planarity, and edge effects due to the lateral heat flow caused by them. The extracted features can be traced back to the original image.
[en] Considered in this paper, a new method of nondestructive control based on the spectra of radio wave radiation of the microwave range wideband scanning receiver. It is experimentally shown that this method has a high accuracy in the determination of the frequency spectrum. This allows the method considered to reach a sensitivity of 5-6 Hz/nm. (paper)
[en] The issues of increasing the effectiveness of the magnetic particle method of nondestructive testing by using a new flaw detection material is considered in the paper. The requirements for flaw detection materials are determined, which ensure the effectiveness of the inspection method. A new flaw detection material – magnetic fluids from iron-containing waste products – has been developed. (paper)
[en] Precision measuring machine manufacturers have been flooded with requests for more precise measurements. Not only high-accuracy and high-throughput, but also nondestructive and non-contact sensing are demanded for the latest precise measurement machines. It is well known that a variety of fine structures beyond micro-meter scale are formed on the surface of industrial products. Thus it is natural trend that the demand of 3D surface measurement with nano-scale will be drastically increased. Reflecting such a situation, Mitutoyo puts much effort into the development of a variety of measurement systems which satisfy such complex demands as a comprehensive manufacturer. In this report, some of the challenges related to industrial manufacturing will be introduced