Search Results

Advanced search parameters have been applied.
open access

Transducer characterization

Description: This report has been prepared specifically for ultrasonic transducer users within the Nondestructive Testing Evaluation (NDE) community of the weapons complex. The purpose of the report is to establish an initial set of uniform procedures for measuring and recording transducer performance data, and to establish a common foundation on which more comprehensive transducer performance evaluations may be added as future transducer performance criteria expands. Transducer parameters and the problems … more
Date: July 2, 1980
Creator: Cross, B. T.; Eoff, J. M.; Schuetz, L. J. & Cunningham, K. R.
Partner: UNT Libraries Government Documents Department
open access

Magnetic testing probe

Description: A cylindrical eddy current tube testing probe is disclosed. Current flow in dual electromagnetic coils separated by an eddy current sensing coil is so directed that magnetic fields of the electromagnet coils have components extending in opposite directions axially of the tested tube and components extending radially of the tube which add in the region of the eddy current sensing coil.
Date: July 7, 1981
Creator: Scott, G.W. & Chitwood, L.D.
Partner: UNT Libraries Government Documents Department
open access

04 nuclear safety: pressure piping crack monitoring detection of metal overstress by acoustic emission. Progress report, July-September 1966

Description: The three main areas of effort have been: (1) definition of the general acoustic response pattern related to the gross aspects of forming and extending a crack in various materials, (2) development of a monitor system prototype concept exclusive of transducers and (3) development of a suitable, high temperature transducer. Tests using double cantilever beam (DCB) specimens of various materials to establish conditions of crack formation and growth have indicated that material ductility is a majo… more
Date: October 28, 1966
Creator: Hutton, P H
Partner: UNT Libraries Government Documents Department
open access

Studies of ultrasonic beam spread in thick sections

Description: The use of hemispherical holes seems to be a valid procedure for monitoring both forward and lateral beam spread. Provided subsequent data analysis and checks show agreement, this type of reflector would be recommended for Code application. The preliminary evaluation of the 45/sup 0/, 2.25 MHz, 2.54-cm (1-in.) circular transducer case shows consistent results and determines an effective beam width that impacts scanning overlap or index. Additional work should be conducted in order to determine … more
Date: January 1, 1981
Creator: McClung, R. W.; Cook, K. V. & Latimer, P. J.
Partner: UNT Libraries Government Documents Department
open access

Ultrasonic angle beam profiling in steel using an EMAT receiver

Description: A system for measuring the beam profile of angle beam search units in steel is described. This technique employs an electromagnetic acoustic transducer (EMAT). The EMAT is sensitive to shear waves polarized parallel to the surface and requires no couplant. A steel block with surfaces cut at angles normal to the ultrasonic beam propagation direction is used. The amplitude distribution of the angle beam is measured at the surface of the test block using the EMAT receiver. The information is recor… more
Date: January 1, 1982
Creator: Becker, F. L. & Busse, L. J.
Partner: UNT Libraries Government Documents Department
open access

Eddy current system for high speed inspection of M-16 cartridge cases

Description: An eddy current system developed to detect cracks, splits, and folds in 5.56 mm cartridge cases at a rate of 1200 cases/minute is described. The system inspects each cartridge case around its entire circumference, and has an operating frequency of 100 kHz which minimizes sensitivity to wall thickness variations. Also discussed is the use of the instrument to monitor cartridge case wall thickness by reducing the operating frequency. At a frequency of 25 kHz, wall thickness can be measured with a… more
Date: March 1, 1978
Creator: Dilbeck, R. A. & Davis, T. J.
Partner: UNT Libraries Government Documents Department
open access

Improved eddy current angle probe

Description: Apparatus is described for detecting flaws in a tubular workpiece in a single scan. The coils of a dual coil bobbin eddy current inspection probe are wound at a 45/sup 0/ angle to the transverse axis of the probe, one coil having an angular position about the axis about 90/sup 0/ relative to the angular position of the other coil, and the angle of intersection of the planes containing the coils being about 60/sup 0/.
Date: February 11, 1982
Creator: Nance, R.A.; Hartley, W.H. & Caffarel, A.J.
Partner: UNT Libraries Government Documents Department
open access

Holographic and acoustic emission evaluation of pressure vessels

Description: Optical holographic interfereometry and acoustic emission monitoring were simultaneously used to evaluate two small, high pressure vessels during pressurization. The techniques provide pressure vessel designers with both quantitative information such as displacement/strain measurements and qualitative information such as flaw detection. The data from the holographic interferograms were analyzed for strain profiles. The acoustic emission signals were monitored for crack growth and vessel quality. more
Date: March 5, 1980
Creator: Boyd, D.M.
Partner: UNT Libraries Government Documents Department
open access

Automatic high-speed process control/quality assurance monitor. [Cartridge cases]

Description: Battelle, Pacific Northwest Laboratories has developed an advanced cartridge case measurement/eject system (CCMES) which automatically inspects and rejects cases up to 1200 per minute. The system consists of a mechanical handler, measurement instruments, and a dedicated computer. System operation is monitored and controlled while the product is being measured. Five case dimensions are measured by an electro-optical system using diode arrays to measure a case image at unity magnification. By sca… more
Date: January 1, 1978
Creator: Coleman, W J & Swinth, K L
Partner: UNT Libraries Government Documents Department
open access

Feasibility study to assess the use of the four quadrant eddy current test method for inspecting 0.042-inch diameter mild detonator fuse

Description: The objective of the project reported was to assess the four quadrant eddy current test method's sensitivity to wall conditions in a 0.042-inch-diameter mild detonator fuse. Specifically, the wall conditions of interest are core offset, average wall thickness, and cracking and inclusions in the wall. Experiments were performed that provided data indicating that these conditions can be determined by the method. It is also concluded that quantitative information on wall conditions can be obtained… more
Date: March 1, 1986
Creator: Prince, J.M.
Partner: UNT Libraries Government Documents Department
open access

Generalized ultrasonic system for microcomputer controlled data collection

Description: A system developed by the NDE Group of the Los Alamos Scientific Laboratory for the automated scanning of objects with an axis of rotation is described. This system is still being expanded to allow greater versatility in the motions. Data which was collected using the system and some typical test objects are also presented and discussed.
Date: January 1, 1980
Creator: Strong, R. D.
Partner: UNT Libraries Government Documents Department
open access

Scattering by flaws in a slab or a half-space

Description: It is the main function of quantitative NDE to detect and to evaluate defects. Some of the most dangerous defects are cracks, especially cracks on or near surfaces. These cracks can be found by scattering ultrasonic waves from them, but up to now there is no theory (at least in the most interesting low-to-intermediate frequency region) which has been implemented to compute scattering from surface or near-surface cracks in 3d. The purpose of the present report is to explain, via a simple scalar … more
Date: January 1, 1982
Creator: Visscher, W.M.
Partner: UNT Libraries Government Documents Department
open access

Effects of microstructure on the speed and attenuation of elastic waves

Description: A unified theory pertaining to the sensitivity of the propagation of an elastic wave to changes in the microstructural details of a material is discussed. In contrast to nearly all previous treatments a first principles approach, using developments from other multiple scattering problems and adapting them to the elastic wave case, is followed. We then present several simple, standard approximations. In the process the validity of the commonly made assumption that ..cap alpha.. = n anti sigma is… more
Date: January 1, 1982
Creator: Gubernatis, J.E. & Domany, E.
Partner: UNT Libraries Government Documents Department
open access

Application of MOOT to scattering of elastic waves from compound inclusions

Description: It is shown how MOOT (method of optimal truncation, a convergent T-matrix scheme) can be used to calculate elastic wave scattering from compound inclusions, i.e., inclusions which themselves contain flaws - inclusions, voids, or cracks. The general equations are derived, and they are solved for a particular axially-symmetric case - a cracked spherical inclusion immersed in fluid. The crack edge is a circle on the equatorial plane; the crack can extend either inward to the center or outward to t… more
Date: January 1, 1980
Creator: Visscher, W.M.
Partner: UNT Libraries Government Documents Department
open access

Ultrasonic Testing With Lamb Waves

Description: A method is described whereby many types of flaws lying close to the surface of a metal can be ultrasonically detected, regardless of the time duration of the interrogating pulses. Lamb waves are established in the metal between a flaw and the surface by an ultrasonic beam which impinges at the proper angle of incidence. A suitably positioned receiver transducer picks up the waves to reveal the flaw. In this method the usually troublesome surface echo is eliminated from the receiver by an acous… more
Date: September 25, 1956
Creator: Worlton, D. C.
Partner: UNT Libraries Government Documents Department
open access

Direct comparison of unloading compliance and potential drop techniques in J-integral testing

Description: Single-specimen J-integral testing is performed commonly with the unloading compliance technique. Use of modern instrumentation techniques and powerful desktop computers have made this technique a standard. However, this testing technique is slow and tedious, with the loading rate fixed at a slow quasi-static rate. For these reasons the dc potential drop technique was investigated for crack length measurement during a J-integral test. For direct comparison, both unloading compliance and potenti… more
Date: January 1, 1984
Creator: McGowan, J. J. & Nanstad, R. K.
Partner: UNT Libraries Government Documents Department
open access

Experiments in the application of ultrasound diffraction tomography for nondestructive testing

Description: We have designed computer programs to simulate ultrasound projection scans and to reconstruct the tomographic planar image. We have also used the reconstruction algorithm on actual test data and have obtained a crude but promising image. 11 refs., 9 figs.
Date: July 1, 1988
Creator: Azevedo, S. G. & Fitch, J. P.
Partner: UNT Libraries Government Documents Department
open access

Improved techniques for the ultrasonic characterization of graphite

Description: Near-conventional pulse-echo flaw detection techniques can be successfully applied to graphite material. If the specimen configuration (i.e., length-to-diameter ratio) is conducive to the choice of ultrasonic test parameters dictated by the material screening tests, then only the test sensitivity needs to be established. Conventional test block approaches to calibration work well; however, uniform homogeneity of the specimens to be tested must be assumed (depending on the graphite, this may be … more
Date: January 1, 1981
Creator: Cook, K. V. & Simpson, W. A.
Partner: UNT Libraries Government Documents Department
open access

Microstructural Effects and Signal-Enhancement Techniques in Ultrasonic Examination of Stainless Steel

Description: Ultrasonic inspection of large-grain stainless steel and stainless steel welds is difficult, and the results obtained are not easily interpreted. In the present study, the effects of stainless steel microstructure on ultrasonic test results are described, and several signal-processing techniques for enhancing ultrasonic flaw signals are discussed.
Date: September 1976
Creator: Kupperman, D. S. & Reimann, K. J.
Partner: UNT Libraries Government Documents Department
open access

Failure analysis and surety design of composite patching systems.

Description: This work presents an experimental evaluation of patch repair of solid laminated composites. The study was focused on destructive and nondestructive tests of full-scale repaired panels under static tension loading conditions. The testing program consisted of ten panels: three pristine, three damaged, three repaired and one repaired with mismatched fiber orientation patch. The evaluated panels were (300 mm x 675 mm) in size and consisted of 6-ply ((-60 /60/0){sub s}) quasi-isotropic laminates. T… more
Date: August 1, 2004
Creator: Hamoush, Sameer (North Carolina A&T State University, Greensboro, NC)
Partner: UNT Libraries Government Documents Department
open access

Fundamental theory of elastic wave scattering by defects in elastic materials: integral equation methods for application to ultrasonic flaw detection

Description: The use of ultrasonic methods in nondestructive testing depends on the interpretation of the scattering of sound waves by flaws. The theory of elastic waves and their scattering in non-uniform media is developed in detail from first principles, and in generality. Both integral equation and differential methods are discussed, with emphasis on the former. General methods for defining scattering cross sections are presented, and conservation theorems are noted. The Born Approximation to the integr… more
Date: May 1, 1976
Creator: Gubernatis, J.E.; Domany, E.; Krumhansl, J.A. & Huberman, M.
Partner: UNT Libraries Government Documents Department
open access

Nondestructive testing of 105mm depleted uranium penetrators.

Description: The report is an information update concerning the nondestructive testing (NDT) activities at Pacific Northwest Laboratories (PNL) for depleted uranium penetrator (XM774, XM833) quality inspection and evaluation. This report covers NDT activities from August to November, 1979.
Date: December 1, 1979
Creator: Morris, C. J. & Foreman, S. J.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen