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[en] Development of Nondestructive Tester for industrial application to detect flaws in aluminum die-casted squirrel case rotor is reported in this paper. Electronic currents are supplied to the end-ring and Hall effect sensors are used to detect the variation of currents which flow in the bar of the rotor. Some signal processing techniques are introduced to classify the signals due to the defects in the bars
[en] A nondestructive ultrasonic technique is presented for estimating the reinforcement volume fractions of particulate composites. The proposed technique employs a theoretical model which accounts for composite microstructures, together with a measurement of ultrasonic velocity to determine the reinforcement volume fractions. The approach is used for a wide range of SiC particulate reinforced Al matrix (SiCp/AI) composites. The method is considered to be reliable in determining the reinforcement volume fractions. The technique could be adopted in a production unit for the quality assessment of the metal matrix particulate composite extrusions
[en] The last ASTM Standard E94 which classified Industrial Radiography films was published in 1984. Since that time inspection contracts in US and worldwide have continued to specify Type 1 and Type 2 films--although these no longer exist. From 1990 there was discussion within ASTM and work was done by ASTM Committee E07-01. The method proposed used data on graininess and gradient to produce an index to represent quality. In the early version the author found that it was possible to have a very fine grain low-contrast film with the same index as a fine grain film, with high contrast. The draft standard was then developed, so that it is possible to classify both types of film in separate groups. The first is the Classical type of film and the second is a Wide Latitude film. In a Classical film, the contrast increases over the useable density range. The range of application standards specify densities generally from D = 2.0 to D = 4.0. A radiologist would expect contrast to be higher at D = 4.0 compared with contrast at D = 2.0. The new ASTM film classification uses a signal to noise ratio--with minimum values for each class for contrast and a maximum value for graininess. The ASTM Classification System uses the same parameters as the European Standard EN584-1 and ISO CD
[en] Electric potential measurement (EPM) technology offers an attractive alternative to conventional nondestructive evaluation (NDE) for monitoring crack growth in harsh environments. Where conventional NDE methods typically require localized human interaction, the EPM technique developed at the Idaho National Engineering and Environmental Laboratory (INEEL) can be operated remotely and automatically. Once a crack-like defect is discovered via conventional means, EPM can be applied to monitor local crack size changes. This is of particular interest in situations where an identified structural defect is not immediately rejectable from a fitness-for-service viewpoint, but due to operational and environmental conditions may grow to an unsafe size with continuing operation. If the location is in a harsh environment where periodic monitoring by normal means is either too costly or not possible, a very expensive repair may be immediately mandated. However, the proposed EPM methodology may offer a unique monitoring capability that would allow for continuing service. INEEL has developed this methodology, supporting equipment, and calibration information to apply EPM in a field environment for just this purpose. Laboratory and pilot scale tests on full-size engineering structures (pressure vessels and piping) have been successfully performed. The technique applicable is many severe environments because the sensitive equipment (electronics, operators) can be situated in a remote location, with only current and voltage probe electrical leads entering into the harsh environment. Experimental results showing the utility of the methodology are presented, and unique application concepts that have been examined by multiple experiments are discussed
[en] An introduction to the principles and methods of image processing is presented. The application of image processing techniques in realtime radiography system with linear detectors is described, and some examples of image processing application are also provided
[en] Quality evaluation of agricultural products has been interested to many researchers for many years and as the result, several nondestructive techniques and so many papers have been reported for quality evaluation of agricultural products. These nondestructive techniques are based on the detection of mechanical, optical, electrical, electro-magnetical, dielectric and vibrational properties of agricultural products that are well correlated with certain quality factors of the products such as color, shape, firmness, sugar content, external or internal defects, moisture content, etc. The sophistication of nondestructive methods has evolved rapidly with modem technologies. In this paper an emphasis was put on reviewing some of those papers and techniques which could be led to on-line measurement for practical use.
[en] The phased array offers many advantages and improvements over conventional single-element transducers such as the straight-beam and angle-beam. The advantages of array sensors for large structures are two folds; firstly, array transducers provide a method of rapid beam steering and sequential addressing of a large area of interest without requiring mechanical or manual scanning which is particularly important in real-time application. Secondly, array transducer provide a method of dynamic focusing, in which the focal length of the ultrasonic beam varies as the pulse propagates through the material. There are some parameters such as number, size, center to center space of elements to design phased array transducer. In previous study. the characteristics of beam steering and dynamic focusing had been simulated for ultrasonic SH-wave with varying the number of phased array transducer's element. In this study, the characteristic of beam steering for phased array transducer has been simulated for ultrasonic SH-wave on the basis of Huygen's principle with varying center to center space of elements. Ultrasonic beam directivity and focusing due to change of time delay of each element were discussed with varying center to center space of elements.
[en] This work presents a brief review of the main activities developed at the testing, production and assembly facilities that the Study and Testing of Structural Components Group (Grupo EECE) has. This Group is a branch of the Non-Destructive and Structural Testing Division (U.A. ENDE) of the National Atomic Energy Commission (CNEA). The main facilities of the EECE Group are: the Low Pressure Experimental Loop (CEBP) and the Prototypes and Machining Sector (Sector de Prototipos y Mecanizado) . A brief description of these facilities are also presented. (author)