Three dimensional computed tomography applications and techniques

(DDC) must he developed to intelpret the strain data measured. The sman-stmcture architecture requires sophisticated computer hardware and software to merge the damage detection concept (DDC) with a sensing system. Structural assessment requirements and the parameters to meet these requirements are the subject of this paper. The implication of the DDC on the electro/optical and computer disciplines will he discussed briefly. The current point strain sensor choice and the neural network application will he identified. 48458 Faron, D.R.; Vaughan, B.J. T h r e e dimensional computed tomography applications and techniques 1991 Industrial Computed Tomography I1, San Diego, California (United States), 20-24 May 1991. pp. 22-26. ASNT (1991) A new high-speed industrial computer tomngraphy machine, the VolumeView I, is described in this paper. It is aimed at quality assessmant applications. The cost of inspections can he minimized by combining digital radioscopy with CT and taking CT slices only at locations identified as questionable by the digital radioscopy image, or at predetermined critical locations. The device is used to detect porosity in aluminium castings. Because of the succe.~.,;of this application there are plans to automate it. Three dimensional CT databases need to be oriented with respect to pan datum and relative coordinate systems and future work is planned in this area using neural network analysis. 48346 Howes, J.R.; Lowe, R.I.; Green, A.T. Non destructive examination of t r a n s f o r m e r s NDT for Today's Applications, 1990 ASNT Fall Conference and Quality Testing Show, Seattle. Washington (United States), 18-12 Oct. 1990. pp. 55-57. ASNT (1990) Prevention of transformer failure, and methods of diagnosing incipient faults, has been the goal of two programs within Hartford Steam Boiler and its technology companies. The primary method enhances an established oil sampling and testing procedure with a knowledge-ba~d computer system that emulates an expert's decision-making process in analyzing gases dis~lved in the transformer's cooling oil to determine faults. A second method, more limited in scope, listens to the transformers to detect the acoustic emissions given off by stressed dielectrics, known as partial discharges. The first is implemented in an expert system and database named TOGA, the Transformer Oil Gas Analyst. The second employs a hand held instrument, a Partial Discharge Detector. 48261 Smith, S.H.; Boiarski, A.A.; Rider, D.G. A calibration approach for s m a r t structures using embedded sensors Proceedings of the 1990 SEM Spring Conference on Experimental Mechanics. Albuquerque, New Mexico (United States), 4-6 Jun. 1990. pp. 310-319. Society for Experimental Mechanics (1990) The primary of this paper is to present a calibration approach for using embedded sen~rs in composite structures or "smart structures". The sensor selected for the "model sensor" is a fiber optic sensor. Optical sen~rs and techniques as applied to the calibration and sensing of mechanical parameters in a composite structure are presented. Calibration approaches and techniques for using interferometrie optical systems are di~assed. The concept of a smart structure work station for the experiments and data prnce&siogis presented. The data processing may he thought of as consisting of two parts. First is the analysis of the raw data into useable parameters (stress, strain, temperature, etc). Second is the synthesis of this basic information into a useful interpretation or set of conclusions concerning the condition of the structure. The software with real time analysis capability will have the form of an expert system tailored for that application. 48238 Huh, Y.-H.; Kim, K.-Y.; Woo, H.-G.; Yang, I.-K. An expert system for automatic evaluation of eddy current signal of steam generator tubes Proceedings of the 10th International Conference on NDE in the Nuclear and Pressure Vessel Industries, Glasgow (Scotland), 11-14 Jun. 1990. pp. 113-116. Edited by M.J. Whittle, J.E. Doherty and K. lida. ASM International, (1990) A proto-type expert system for automatic evaluation of eddy current signal of steam generator tubes was built to solve problems existing in the conventional eddy current testing (ECT). The prototype is currently being enlarged on HP 9000/370 workstations. The new system uses C language and optical disks, offers ECI" Database Management function, and adopts attribute grammar for pattern recognition. This paper de~ribes the design of the expert system. 48233 Huh, Y.-H.; Kim, K.-Y.; Woo, H.--G.; Yang, I.-K. An expert system for automatic evaluation of eddy c u r r e n t signal of steam generator tubes Proceedings of the 10th International Conference on NDE in Nuclear and Pressure Vessel Industries, Glasgow (Scotland), 11-14 Jun. 1990. pp. 191-198. Edited by M.J. Whittle, J.E. Doherty and K. lida. ASM International, (1990) A pinto-type expert system for automatic evaluation of eddy current (EC) signal of steam generator (S/G) tubes was built to solve problems existing in the conventional eddy current testing (ECT). The prototype is currently being enlarged on a HP 9000/370 workstation. The new system uses C language and optical disks, offers ECT Database Management function, and adopts attribute grammar for pattern recognition. This paper describes the design of the expert system.

Kato, Y.; Sugita, Y.; Onda, K.: Okudaira, E.; Matsui, S.; Itoga, K.; Sugimoto, K. 48206

Development of computer-aided radiographic inspection system (!): description of system

NDT&E International Volume 25 Number 1 1992

Proceedings of the 10th International Conference on NDE in the Nuclear and Pressure Vessel Industries, Glasgow (Scotland), I 1-14 Jun. 1990. pp. 687-692. Edited by MJ. Whittle, J.E. Doherty and K. lid& ASM International, (1990) The authors have developed a computer-aided radingmphic inspection system using the digital image processing and the defect categorization expert system. Features of the system are as follows: (I) The system follows almost the saroe procedure as an inspector does. (2) The threshold level of potential defect extraction can be arbitrary changed. (3) Inspectors' koowledges are introduced at the image processing stage. (4) The konwledges which cannot be obtained directly from radiographs are used in the identification of kind of defect. (5) The system is designed in such a way that radiographs which the system cannot interpret with high level of confidence are left to inspectors' interpretation although it can be used in automatic mode. The application of the system showed that the interpretation by the system compared very well with the inspectors' interpretation.

Sugita, Y.; Onda, K.; luchi, S.; /toga, K.; Harada, 7".;Sugimoto, K.; Michiba, K. 48205

Development of computer-aided radiographic inspection system (il): method of identification a n d categorization of welded detects Proceedings of the 10th International Conference on NDE in the Nuclear and Pressure Vessel Industries, Glasgow (Scotland), 11-14 Jun. 1990. pp. 693-699. Edited by M.J. Whittle, J.E. Doherty and K. lida. ASM International, (1990) Digital image processing and artificial intelligence technologies are applied for the radiographic inspection of welded joints. Major developments of the image processing are described in detail. They include the methods of evaluating peoetrameter sensitivity, enhancement and extraction of cracks as well as volumetric and other planar defects, and eliminating non-relevant indications extracted together with images of real defects. Also deserihed is the method of categorizing weld defects using expert system, especially how to acquire hales to he used for the expert system. By applying these technologies jointly, the computer-aided radiographic inspaetion system equivalent to a human inspector can be built. 48101 Pinto, G.A.; Ventres, C.S.; Ginty, C.A.; Chamis, C.C. In-service health monitoring of compositestructures Proceedings of the 1990 SEM Spring Conference on Experimental Mechanics, Albuquerque, New Mexico (United States), 4-6 Jun. 1990. pp. 304-309. Society for Experimental Mechanics (1990) • In the aerospace industry a definite need exists for a composites health monitoring expert system to meet today's current needs and tomorrow's future demands. The primary goal for this conceptual health monitoring system is functional reliably for in-service operation in the environments of various composite structures. The underlying philosophy of this system is to utilize proven vibration techniques to assess the structural integrity of a fibrous composite. Statistical methods are used to determine if the variances in the measured data are acceptable for making a reliable decision on the health status of the composite. The flexible system allows for algorithms de~ribing any composite fatigue or damage behavior characteristics to be provided as an input to the system. Alert thresholds and variances can also be provided as an input to this system, and may be updated to allow for future changes/refinements in the composite's structural integrity behavior. 48099 Benoist, B.; Cherpentier, C.; David, B.; Pigeon, M. Expert system designed to increase the reliability on steam generator tubing Proceedings of the 10th International Conference on NDE in Nuclear and Pressure Vessel Industries, Glasgow (Scotland), 11-14 Jon. 1990. pp. 187-189. Edited by M.J. Whittle, J.E. Doherty and K. lida. ASM International, (1990) The aim of this paper is to present an expert system for the automatic analysis of multifrequency E.C. signals which ameliorates the reliability of the control of steam generator tubing. The expert system SOCRATE (Systeme Operant sur Criteres et Regles pour I'Analyse des Tubes d'Ecbangeurs) has a detailed knowledge of the characteristics of E.C. signals and if necessary it can use the algorithms of signals processing eg. adaptive filtering (adaptive interpolation). The technique which we use for the analysis of E.C. signals, combines the information contained in all the frequencies. We can therefore formulate a result which represents the degree of coherence of the different hequencies i.e. the reliability criterion, to he able to furnish a reliable evaluation of the depth of a given defect, and also to he able to determine the existence of multiple defects, that is two defects on the same section of tubing. The range of defects that SOCRATE can thus analyse will be illustrated by a series of examples. 48098 Shankar, R.; Williams, R. An expert system for BWR weld examination Proceedings of the 10th International Conference on NDE in Nuclear and Pressure Vessel Industries, Glasgow (Scotland), 11-14 Jun. 1990. pp. 297-302. Edited by M.J. Whittle, J.E. Doherty and K. lid& ASM International, (1990) A personal computer (PC)-based expert system "shell" was used to assemble a knowledge ba~ to assist experienced operators in discrimination of intergnmular stress corrosion cracking (IGSCC) from benign reflectors in the inspection of pipe-tocomponent welds. The rules in the knowledge base include plant inspection history. ultrasonic examination data, and radiography testing data. The expert system is configured in a question-answer format and comists of more than 300 facts and decision rules. The system has been integrated with an imaging system capable of displaying and computing image features pertinent to the consultation and a ray tracing program for simulating ultrasonic examination scenarios. The integrated capability was

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