Engineering Fracture Mechanics, Vol, 35, Nos. 1/2/3, pp. 313-320 (1990) T/me Domain Reflectometry (TDR) is an electromagnetic pulse testing technique

using Radar theory. Recently, this technique has been applied to monitor rock movement induced by underground mining. Coaxial cables are grouted into the rock mass which is expected to move. Rock movement deforms the cable and produces changes in the TDR reflection signature. This forms a very good tool, and could be used to detect and monitor fracture or damage within a large concrete structure. Experimental data will be presented to demonstrate the applicability of this technique. Results show positive. Fracture and relative block movement can be measured quantitatively. This techniqne can be applied in building warning and monitoring systems for the safety of large concrete structures,

43110 dos Reis, H.L.M. Acousto-ultrasonies: applications to wire rope, wood fiber hardboard, and adhesion Acousto-Ultrasonics, Theory and Application. Edited by J.C. Duke, Jr., pp. 283-299, Plenum Press, 353pp (1989). ISBN 0306430134

Applications of the Acousto-Ultrasunie Stress Wave Factor Technique (SWF) to the nondestructive evaluation/characterization of wire rope, wood fiber hardboard, and adhesion between mlYner-like materials and steel substrates are presented. It was observed that for each application the SWF technique has the potential of being used as a nondestructive testing tool. The SWF technique proved successful to monitor progressive damage in wire rope and wood fiber hardboard, and to monitor the strength of the bond between rubber layers and steel plates.

43086 Wayne Hennigar, G. Hel ium leak testing of pressurized telephone cables Materials Evaluation, Vol. 48, No. 2, pp. 124-127 (Feb. 1990)

Many telephone cables are pressurized and are monitored by elaborate com- puterized pressure- and flow-tran~ucer systems. Early warning systems can detect leakage automatically but cannot identify its exact location. The computer information is provided to the maintenance technician, and it becomes his responsibility to locate and repair the leak. With good data and careful calculations, maintenance technicians can sometimes establish the actual leak location to within several meters. The final step-pinpointing the leak-generally involves the use of a tracer gas. Several types of tracer gas, including helium, refrigerant, and sulfur hexafluoride, have been used by telcos over the years. However, helium is the most popular because it is inert and its low specific gravity makes it tend to rise quickly to the surface. Telcos have used a single-male thermal conductivity combustible gas indicator to detect helium.

42703 Toros, R.; Visintin, R. Advanced equipment for the inspection of lift ropes Proceedings of the International Conference on Monitoring, Surveillance and Predictive Maintenance of Plants and Structures, Tanrmina-Giardini Naxos, Sicily (Italy), 15-18 Oct. 1989, pp. 508-513. Italian Society for Nondestructive Testing

There follows an examination of the problems related to the periodic checking of the working of the multiple cables of lifting installations (in particular lifts and goods-lifts), and the presentation of a new instrument for the magnetoinductive examination of these ropes.

42687 Golke, A.; Tietze, M. Computer-assisted eddy-current testing on wires, bars and pipes Materialprufung, Vol. 31, No. 11-12, pp. 363-366 (Nov.-Dec. 1989)

Two new eddy-current test units, namely a traverse-coil testing system and a rotating-bead testing system are introduced, which can he combined with the aid of a computer to a uniform operating, dispMy and control unit and which can also he combined with each other. At the example of the proof of test errors with a different extension in depth and position in tungsten wire, thin-walled copper pipes and combustion elemcm enveloping the tube of zircalloy, the operating efficiency of the test systems is illnstmted.

42584 Duke, J.C.: Henneke, E.G.; Kierman, M.T.; Grosskopf, P.P. Study of the stress wave factor technique for evaluation of composite materials

Virginia Polytechnic Institute and State University Blacksburg (United States), N89-21256f7/GAR. 61pp. (Jan. 1989)

The acousto-ultrasonic approach for nondestructive evaluation provides a measure- ment procedure for quantifying the integrated effect of globally distributed damage characteristic of fiber reinforced composite materials. The evaluation procedure provides a stress wave factor that correlates closely with several material performance parameters. The procedure was investigated for a variety of materials including advanced composites, hybrid structure bonds, adhesive bonds, wood products, and wire rope. The research program focused primarily on development of fundamental understanding and applications advancements of acousto-ultrasonics for materials characterization. This involves characterization of materials for which detection, location, and identification of imperfections cannot at present be analyzed satisfactorily with mechanical performance prediction models, in addition to presenting definitive studies on application potentials, the understanding of the acousto-ultrasonic method as applied to advanced composite is reviewed.

42130 Ma/yshev, L.A.; Chentsov, V.P. Acoustic-emission method o f determin ing the bending resistance of cables Soviet Journal o f Non-Destructive Testing, Vol. 24, No. 9, pp. 627-630 (May 1989)

Tim methods and means of evaluating the bending resistance of flexible cables are analyzed. An acoustic-,¢mission method of determining the actual bending resistance of cables is examined. Recommendations for the application of the method are given.

41896 Vary, A. Aeousto-ultruonics: an update Journal of Acoustic Emission, Vol. 8, Nos. 1-2, pp. 5175-5178 (Jan . - Jan. 1989). Special Supplement- Extended Summaries of papers to be presented at the World Meeting on Acoustic Emission, Charlotte, North Carolina, USA, 20-23 Mar. 1989

Since it was first introduced, the aconsto-ultmsonic approach has been applied to a variety of materials, including fiber reinforced composites, adhesively bonded materials, paper and wood products, cable and rope, and also haman bone. Application potentials and limitations of the approach are reviewed. Basic methodology and gu/delines are discussed. "/'he underlying hypothesis for the approach is given and theory development and signal analysis needs are indicated.

41867 Graham, R.C.; Smith, J.D. Eddy current apparatus and method for controlling a rod mill on the basis of faults detected per unit time U.S. Patent No. 4,808,926 (28 Feb. 1989)

This new device uses eddy current testing to control a rod mill used for drawing wire from a rod. The eddy current tester produces fault signals on encountering defects in the wire. These are counted per unit time. Count signals with magnitudes related to fault rote in the wire are produced. Their rate of increase is compared to a reference value. If exceeded a rod mill shutdown signal is generated.

41813 Stupin, D.M.; Stokes, G.H.; Steven-Setchell, J. Near.real.time radiography detects very small wires and thickness variations International Advances in Nondestructive Testing. Edited by Warren J. McGonnagle. Vol. 14, pp. 323-333, Gordon and Breach Science Publishers (1989)

The author uses radiography with two simple image-processing techniques and 17 keV x-rays (45 kV pk) from a molybdenum anode to detect very small changes in a real density and very small-diameter wires. These image-processing techniques will improve the performance of any digital-imaging x-ray system and can be performed in about 30 s. Furthermore, the x-ray energy is nearly optimum for examining ,some plastic and ceramic parts. This technique can he modified for examining materials at other energies.

41721 Coultate, A.K. Non-destructive magnetic testing device British Patent No. GB 2,206,969 (18 Jan. 1989)

A non-destructive testing device for a magnetically conductive element, such as a rope, includes a housing which is made up of two halves which are hinged together and capable of being secured by a catch. The longitudinal element passes through guide means which position it centrally within the device and magnetic poles of two pole pieces arranged diametrically opposite one another send a flux in one direction through the element. Changes in the magnetic flux internally or externally are detected by .sensors and any breaks in the wires of corrosion which cause a change of flux is monitored with a signal able to be produced to identify the position of the fault in the element.

41537 Harrop, I.; Summerscales, J. Acoustic emission testing of the structural integrity of multicore cable British Journal of Non-Destructive Testing, Vol. 31, No 7, pp. 383-387 (Jul. 1989)

Cables are widely used in the marine envimnn~m as mechanical, electrical and occasionally optical links in offshore drilling, ocean thermal energy projects, towing, salvage and remote control of equipment. In heavy seas the mechanical loads imposed on such cables can be significant with respect to the strength of the components of the cable. Failure of the cable in such applications can he catastrophic in tenns of loss of equipment and/or life. This paper will review the application of acoustic emission monitoring to rope, wire and cable, and will then report the results of experimental tests on multicore cables loaded in tension and monitored by acoustic emission techniques.

41473 Weischedel, H.R.; Ramsey, R.P. Electromagnetic testing, a reliable method for the inspection of wire ropes in service NDT International, Vol. 22, No. 3, pp. 155-161 (Jun. 1989)

The art of wire rope inspection has progressed rapidly over the past few years. Presently available electromagnetic ittsmLrnents are now much easier to operate and provide an important (in some cases indispensable) element of wire rope inspection. Test data obtained from these instruments can provide accurate quantitative estimates of safety-related wire rope parameters such as loss of metallic cro~s- sectional area (LMA) and provide a more reliable basis for estimating the condition and remaining service life of a rope. This paper illustrates the use of modem nondestructive test methods to asse,~s the safety of wire ropes in service.

41464 Koido, d.; Hoshikawa, H.; Ishibashi, Y.; Saeki, N.; Araki, N. and Kuwano, K. Flux fill-factor measurement of seamless wire using eddy current technique Proceedings of the 12th World Conference on Non-Destructive Testing, Amsterdam (Netherlands) 23-28 Apr. 1989, Vo. 1, pp. 336-341. Edited by J. Boogaard and G.M. van Dijk, Elsevier, (1989)

A flux fill-factor (the ratio of weight of flux to the weight of wire per unit length) measurement method for seamless flux-cored wire, using eddy current testing, has been investigated. It has employed the DC magnetic saturation method to enhance sensitivity for measurement of fill-factor.

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