Papers by Keyword: Ultrasonic Testing (UT)

Abstract: In order to promote the phased array technology for the application of weld inspection, the advantage of phased array technology was introduced and the application of rails welding inspection with phased array technology was also introduced. Through detecting nature and machining flaws of aluminum-themic welding of rails, contrast to results of conventional ultrasound test, validate the effectiveness of ultrasonic phased array method, concluding characteristics of ultrasonic phased array method for the aluminum-themic welding of rails. From the result of application, the efficiency of weld inspection could be greatly improved and the inspection cost could be greatly reduced by phased array technology.

Abstract: Due to the advantages of corrosion resistance, no scaling, light weight, polyethylene pipes are widely used in low pressure gas networks and their safety has also been duly noted. As for heat fusion welding of PE pipeline connectors, there is no effective means of detection internally. In this paper, welding specimens were tested under the condition of normal conditions, low melting temperature, low pressure, low heating time melts, underwater welding by the United States imported equipment based on the echo pulse method of ultrasonic testing technology. Comparing with the results of related conditions of tensile tests, this paper found that ultrasound can effectively identify internal defects of hot-melt connectors. And there is a corresponding relationship between the ultrasonic system evaluation grades and the elongation at break, the higher the level, the lower the elongation at break. Related research results can provide the basis for the establishment of PE pipe ultrasonic non-destructive testing inspection standards.

Abstract: The development of signal processing technology not only improves the reliability of qualitative and quantitative ultrasound detection, but also promotes the sensitivity and precision. This paper introduces the new progress of signal processing technology in application of Ultrasonic Nondestructive Testing, including the basic principle, characteristic and localization of Wavelet Transform, Adaptive Filter Technique, Artificial Neural Network and Support Vector Machine application in Ultrasonic Testing, and the trend of development in the future.

Abstract: As the detection efficiency and defect evaluation accuracy of traditional ultrasonic testing of weld is low, in this paper a new control system is developed to accomplish high-efficiency and high-precision evaluation of weld. This system includes Centralized Control, Control of ultrasonic probe and running mechanism. The heart of the system is DSP, and it can control motion of the scan robot along the circular rail and ultrasonic probe along radial direction of circumferential weld, and realize collection and processing of ultrasonic signal by the comprehensive application of computer, automation, precision instrument, motor driver technology. Practice shows that this new system has realized digital, intelligent, automation of ultrasonic weld inspection, and improved Reliability and efficiency of weld inspection.

Abstract: This paper reports on a study of the propagation characteristics of visco-elastic, Rayleigh waves induced by laser ultrasonics in half space structures. Beginning with the Kelvin model, the characterization equation and the normal displacement of visco-elastic Rayleigh waves in are derived and the influence of the visco-elastic modulus on dispersion and attenuation are discussed. The transient response of a visco-elastic Rayleigh wave is also simulated by means of Laplace and Hankel inversion transforms. The papers results and conclusions will provide insights and guidance for estimating visco-elastic parameters

Abstract: The pipeline which is plugged after leaking will spend a lot of resources, therefore it is imperative to investigate safety analyzing method of pipeline. To reduce the production cost that timely test and evaluate the in-service pipeline, and take measures to extend the life span have been the key matter. To solve this problem, the article demonstrates the ultrasonic testing method. It is significant for the long-distance pipeline running safely.

Abstract: This paper designed a fpga-based ultrasonic flowmeter, and used verilog language design fpga control unit.The microcontroller was the core of the ultrasonic transceiver circuit. Peripheral circuit is designed to be simple and reliable, the fpga advantage in raising the maximum clock frequency, greatly improves the measurement accuracy of the design.

Abstract: The differences of instantaneous frequency (IF) characteristics between the defect echo and the noise can be used to detect defect and suppress noise for ultrasonic testing signal. Therefore, the IF is one of the important instantaneous parameters of ultrasonic testing signal. To estimate the IF of ultrasonic testing signals more effectively, the peak of time-frequency representation (TFR) from matching pursuits (MP) decomposition is proposed. The performances of IF estimators are compared on the simulated signals at different signal-to-noise ratio (SNR) and the real ultrasonic testing signal. The simulation results present that the proposed method can estimate accurate IF at different SNR.

Abstract: According to the different thickness of the thin coatings, the echo signal of ultrasonic testing was extracted. The sound velocity in the coating medium was obtained by solving the mathematical model for transfer function and the time delay spectrometry method, and the coating thickness was calculated, the comparison error of the calculated thickness and the actual thickness, combined with the actual thickness of the coating. The results showed that, two kinds of testing methods are able to detect thin coating thickness.

Abstract: Reliability analysis of the procedure of ultrasonic technique before inspection has been proved to be essential to ensure the equipment operation safety. The conventional evaluation methods are based on statistical models and a remarkable sample size is needed to get a accurate result. In this work, the Bootstrap model for small sample data is established based on the re-sampling technique. The probability of detection (POD) curves in different conditions are calculated based on the Bootstrap model, and used for quantitative analysis the influence of inspection parameter on stainless steel auto ultrasonic testing result. The calculated result based on bootstrap model is compared with which based on model assisted POD method. The results indicate that Bootstrap model is an efficient tool for the reliability analysis of inspection with small sample data, and insure the inspection result.