Ultrasonic evaluation

Elastic properties, ultrasonic evaluation Electronic properties radial electron density... 

Ozutsumi, K., Nade, T., Watanabe, H., Tsujimoto, K., Aoki, Y., and Aso, H. 1996. Non-destructive, ultrasonic evaluation of meat quality in live Japanese black steers from coloured images produced by a new ultrasonic scanner. Meat Sci. 43, 61-69. 

The results of LASAT can be correlated and thus validated by ultrasonic evaluation in a transmission configuration that reveals delaminated areas when the ultrasonic wave is not transmitted (see Chapter 7.5.1.4, Figure 7.31). 

Bluth El, Merrit CRB, Sullivan LA (1979) Ultrasonic evaluation of the stomach, small bowel and colon radiology. 124 791-792... 

Rosa-Fox NDL, Morales-Florez V, Toledo-Femandez JA, Pinero M, Esquivias L, Keiderling U (2008) SANS study of hybrid silica aerogels under in-situ uniaxial cranpression. J Sol-Gel Sci Techn 45 245-250 Grob J, Schlief T, Fricke J (1993) Ultrasonic evaluation of elastic properties of silica aerogels. Mater Sci Eng A168 235-238... 

The speed of sound in an elastic medium is a function of elastic modulus and density as follows v = ElpY, where p is velocity, E is modulus, and p is density. Because ceramics are stiffer and less dense than metals, the speed of sound in ceramics is greater than in metals. For example, the speed of sound in iron is 5.13 mm/ ps, compared to 9.78 mm/ps in alumina. This means that, at the same frequency, the wavelength is greater in a ceramic and the resolution essentially halved. This difficulty and the fact that critical flaws in ceramics are much smaller than those in metals mean that frequencies between 10 and 100 MHz are required for ultrasonic evaluation of ceramics. 

A. Pilarski, Ultrasonic evaluation of the adhesion degree in layered joints. Mater. Eval. 43, 765 (1985). 

Chiara A, Chirico G, Barbarini M et al (1989) Ultrasonic evaluation of kidney length in term and preterm infants. Eur J Pediatr 149 94-95... 

Tang, Z., Cheng, A. and Achenbach, J.D., Ultrasonic evaluation of adhesive bond degradation by detection of the onset of nonlinear behavior. J. Adhes. Sci. Technol., 13, 837-854 (1999). 

Lavrentyev, A.l. and Rokhlin, S.I., Ultrasonic evaluation of environmental degradation of adhesive joints. Rev. Prog. Quant. Nondestruct. Eval., 13B, 1539-1546(1994). 

Grop, J., Schlief, T., and Fricke, J. (1993) Ultrasonic evaluation of elastic properties of silica aerogels. Mater. Set Eng. A,... 

The suggested method is appropriately implemented at the practice. The cost and working hours of unit measurement of it is less than of any alternative method of destructive test and with respect to the authenticity inspection of Stress-Deformation the given method is inferior only to destructive testing. The method was successfully implemented while evaluation of service life of main pipe-lines sections and pressure vessels as well. Data of method and instrument are used as official data equally with ultrasonic, radiation, magnetic particles methods, adding them by the previously non available information about " fatigue " metalwork structure. 

The technique presented above has been extensively evaluated experimentally using ultrasonic data acquired from a test block made of cast stainless steel with cotirse material structure. Here we briefly present selected results obtained using two pressure wave transducers, with refraction angles of 45° and 0°. The -lOdB frequency ranges of the transducers were 1.4-2.8 MHz and 0.7-1.4 MHz, respectively. The ultrasonic response signals were sampled at a rate of 40 MHz, with a resolution of 8 bits, prior to computer processing. 

A novel approach for suppression of material noise in ultrasonic signals, based on noncoherent detector statistics and signal entropy, has been presented. Experimental evaluation of the technique, using ultrasonic images from samples with coarse material structure, has proven its high performance. 

In the near future the technique will be further evaluated using ultrasonic signals from natural defects, e.g., fatigue cracks. The performance measure and the parameter optimization procedure wilt also be refined in order to obtain a computationally efficient implementation, easy to use for a trained operator. 

Chan,R.W.Y., Hay,D.R., Matthews,J.R., MacDonald,H.A., (1988), Automated Ultrasonic System for Submarine Pressure Hull Inspection , Signal Processing and Pattern Recognition in Nondestructive Evaluation of Materials, C.H.Chen (ed). Springer-Verlag, pp. 175-187... 

Aerospace struetwes made of composite. As part of the evaluation of the developed ultrasonic spectroscopy system the NSC software was tested on ultrasonic resonance spectra from composite panel samples. Spectra were collected with four different types of damages, and from flawless samples. The damages included a small cut in one of the carbon fiber... 

We have presented a neural network based spectrum classifier (NSC) aimed at ultrasonic resonance spectroscopy. The ultrasonic spectroscopy and the NSC has been evaluated in many industrial applications, such as concrete inspection, testing of aerospace composite structures, ball bearings, and aircraft multi-layer structures. The latter application has been presented in some detail. 

The evaluation of the proposed algorithms for the classification of ultrasonic resonance spectra clearly indicated that an adequate classifier can in many practical cases be obtained by... 

In service inspections of French nuclear Pressure Water Reactor (PWR) vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a "direct" field that passes through the inner surface (water/steel) of the component containing the defect and a "secondary" field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. 

There have been numerous efforts to inspect specimens by ultrasonic reflectivity (or pulse-echo) measurements. In these inspections ultrasonic reflectivity is often used to observe changes in the acoustical impedance, and from this observation to localize defects in the specimen. However, the term defect is related to any discontinuity within the specimen and, consequently, more information is needed than only ultrasonic reflectivity to define the discontinuity as a defect. This information may be provided by three-dimensional ultrasonic reflection tomography and a priori knowledge about the specimen (e.g., the specimen fabrication process, its design, the intended purpose and the material). A more comprehensive review of defect characterization and related nondestructive evaluation (NDE) methods is provided elsewhere [1]. 

Article is denoted to the investigation and the creation of the new ultrasonic and information technologies (IT) and the technical methods of non-destructive evaluation (NDE) of material state in the product, which are based on principles of ultrasonic computing tomography (USCT). These results concern two important questions ... 

R. Coulette, E. Lafond, F. Lepoutre, D. Balageas, M.-H. Nadal and C. Gondard, Laser ultrasonics NDE of two-layered samples . Review of Progress in Quantitative Nondestructive Evaluation, Vol 17, edsD. O. Thompson and D. E. Chimenti (Plenum, New York, 1998), to be published. 

Lasaygues, P.,. Lefebvre, J.P., and Mensah S., Deconvolution and Wavelet Analysis on Ultrasonic Reflection Tomography, III International Workshop, Advances in Signal Processing for Non Destructive Evaluation of Materials, Quebec, Canada, (1997). 

The control of the airborne sound location system, the coupling monitor and the real-time evaluation of all signals, including the echo indications from the ultrasonic instrument, is carried out on two additional boards in the PC. The graphic user interface (under Windows 95), including online help, enables an easy operation of the system. The evaluation program links all echo indications in real time with the probe position and displays them in a graphic repre-... 

Calibration of the ultrasonic instrument, including plotting of a recording curve (DAC), or a reference reflector for a DOS evaluation, or loading of the existing test dataset... 

Up to now the Reference Block Method and the DGS-Method are world wide the most important techniques for evaluating defect signals in manual Ultrasonic Testing. Even today, individual national standards refer to either one of these two echo evaluation techniques. However, both reflected echo signals from natural defects are compared with an echo from a known reference reflector at the same distance. The result of the evaluation is either... 

With the reference block method the distance law of a model reflector is established experimentally prior to each ultrasonic test. The reference reflectors, mostly bore holes, are drilled into the reference block at different distances, e.g. ASME block. Prior to the test, the reference reflectors are scanned, and their maximised echo amplitudes are marked on the screen of the flaw detector. Finally all amplitude points are connected by a curve. This Distance Amplitude Curve (DAC) serves as the registration level and exactly shows the amplitude-over-distance behaviour" of the reference reflector for the probe in use. Also the individual characteristics of the material are automatically considered. However, this curve may only be applied for defect evaluation, in case the reference block and the test object are made of the same material and have undergone the same heat treatment. As with the DGS-Method, the value of any defect evaluation does not consider the shape and orientation of the defect. The reference block method is safe and easy to apply, and the operator need not to have a deep understanding about the theory of distance laws. 

We showed that experimentally recorded DACs and synthetically generated DGS curves are equivalent if the described requirements are fulfilled. Consequently an echo amplitude evaluation program has been developed which combines both techniques in one instrument. The software of the new state-of-the-art Ultrasonic Notebook USLT 2000 allows, apart from many other new possibilities, the combined or exclusive use of the reference block and the DGS method for amplitude evaluation. Even in those situations where DACs cannot be re-... 

We are confident that any user of this combined evaluation technique, as well as the development of future test standards for manual ultrasonic testing will benefit from this result, because it allows a greater flexibility in the applicable method without loosing reliability. Often an expensive production of a reference block can be avoided and therefore testing costs are reduced. Since all calculations are performed by a PC, the operator can fully concentrate on his most important duty scanning the workpiece and observing the A-scan. Additional time will be saved for the test documentation, since all testing results are stored in the instrument s memory (the PC s hard drive) with full link to the Software World (Microsoft Word, Excel, etc.). 

Defect Evaluation in Diffusion Bonding Interface of Dissimilar Metals Using Ultrasonic Testing Method. 

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