Evaluation techniques, nondestructive

GNETICMATERIALS - THIN FILMS AND PARTICLES] (Vol 15) -imaging techniques [NONDESTRUCTIVE EVALUATION] (Vol 17) -useinNDE [NONDESTRUCTIVE EVALUATION] (Vol 17)... 

S. Gunasekaran, Nondestructive Food Evaluation Techniques to Analyze, Marcel Dekker, New York, 2004. 

Some of the factors involved in choosing a particular nondestructive evaluation technique are the primary reason or objective, the type of flaw to be detected, the size and orientation of the flaw, the location of the flaw in the sample, the size and shape of the sample and the nature of the sample. It is also necessary to know the type of flaws that are acceptable or unacceptable in the sense that flaws may be deleterious or nondeleter-ious. The size, type, orientation and location of the flaws determine whether they are acceptable or unacceptable as per the code, or standard given by American Society of Mechanical Engineers Pressure Vessel Code, American Welding Society Structural Welding Code or any other applicable code or standard. 

Evaluating composites nondestructively not only includes the use of an adapted NDT technique but also encompasses the disciplines of physics, material science, statistics, and computing. The capabilities of NDE in assessing the structural integrity of composites continue to grow, and proper employment of each technique remains a real challenge. 

C. E. Smith, G. N. Morscher, and Z. H. Xia, Monitoring Damage Accumulation in Ceramic Matrix Composites Using Electrical Resistivity, Scripta Materialia, 59 [4] 463-466 (2008). Smith, C. E., Morscher, G. N. and Xia, Z., Electrical Resistance as a Nondestructive Evaluation Technique for SiC/SiC Ceramic Matrix Composites Under Creep-Rupture Loading, International Journal of Applied Ceramic Technology, 8 298-307 (2011). 

Unfortunately, most nondestructive evaluation techniques are not effective at finding encapsulation defects. Voids and density variations are not readily detectable by visual inspection or by x-ray analysis. In the case of x-ray, the inherently low density of encapsnlant foams limits the contrast between filled and unfilled (void) regions. Scanning aconstic microscopy (SAM) has had some limited success when the encapsulant layer is relatively thin, which is not often the case. Witness samples taken during the casting process are used to confirm foam density. 

Chatterjee K, Tuli S, Pickering SO, Almond DP (2011) A comparison of the pulsed, lock-in and frequency modulated thermography nondestructive evaluation techniques. NDT E Int 44(7) 655-667 Clark MR, McCann DM, Forde MC (2003) Application of infrared thermography to the non-destructive testing of concrete and masonry bridges. NDT E International 36(4) 265-275... 

Notea A., Applications of Film Tomography Technique for QNDE , Review of Progress in Quantitative Nondestructive Evaluation, vol. 6A, 1987, pp. 433-440. 

The objective ia any analytical procedure is to determine the composition of the sample (speciation) and the amounts of different species present (quantification). Spectroscopic techniques can both identify and quantify ia a single measurement. A wide range of compounds can be detected with high specificity, even ia multicomponent mixtures. Many spectroscopic methods are noninvasive, involving no sample collection, pretreatment, or contamination (see Nondestructive evaluation). Because only optical access to the sample is needed, instmments can be remotely situated for environmental and process monitoring (see Analytical METHODS Process control). Spectroscopy provides rapid real-time results, and is easily adaptable to continuous long-term monitoring. Spectra also carry information on sample conditions such as temperature and pressure. 

Cause, R.L., A nonconiacting scanning photoelectron emission technique for bonding surfaces cleanliness inspection. NASA Technical Memorandum NASA TM-100361, 1989. Schirato, R.C., Polichar, R.M. and Shreve, D.C., In Proc JANNAF Nondestructive Evaluation Subcommittee Meeting. Chemical Propulsion Information Agency, Columbia, MD, 1992. 

There are several schemes for nondestructive evaluation. Changes in electrical resistance can be used to follow corrosion. Radiographic techniques involving X-rays and gamma rays have been applied. Transmitted radiation as well as back scattered radiation have been used. 

Acoustic emission (AE) technique, in nondestructive evaluation, 17 425 Acoustic fields, filtration and, 11 324 Acoustic methods, of emulsion characterization, 10 128 Acoustic microscope, 16 505... 

Eddy-current separation, 75 435 of nonferrous metallics, 75 455-457 Eddy-current separator, 27 447-448 Eddy-current technique, in nondestructive evaluation, 77 420 Eddy diffusion, 9 658 Eddy viscosity, 77 779 Eddy-viscosity-based models, 77 780 Edecrin, 5 169... 

Thermal techniques, in nondestructive evaluation, 17 420-421. See also Heat entries Heating entries Thermal-transfer printing, 9 242, 338 Thermal transfer processes, 19 320 Thermal transition, in shape-memory polymers, 22 357-358, 359t, 360, 361-362... 

Ultrasonic relaxation loss, of vitreous silica, 22 429-430 Ultrasonics, for MOCVD, 22 155 Ultrasonic spectroscopy, in particle size measurement, 13 152-153 Ultrasonic techniques, in nondestructive evaluation, 17 421—425 Ultrasonic testing (UT) piping system, 19 486 of plastics, 19 588 Ultrasonic waves, 17 421 Ultrasonic welding, of ethylene— tetrafluoroethylene copolymers,... 

Ihe paper of Ref 2, abstracted in Ref 3> reports a technique that will yield insight into the quality of EBW devices in a nondestructive manner. By employing a self-balancing bridge it is possible Co ascertain die electrothermal and nonlinear behavior of the device. A sinusoidal current is passed thru the device which provides a signal in the form of a unique Lissajous Display (See Note, below). This display can be qualitatively evaluated and abnormal units can be readily detected... 

Yantarasri, T., Somsrivichai, J., and Kalayanamitra, K. 1999. Nondestructive techniques for quality evaluation of pineapple fruits. The Third International Pineapple Symposium, Pattaya, Thailand. 

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