Numerical Simulation And Experimental Investigation Of Defect Detection In Pipes Using Ultrasonic Guided Waves

Pipe is the lifeline of oil transport. It is also used widely in daily life and chemical products transportation. But when pipes are used, the defects which caused by corrosion or aging defects will not only cause huge losses, but also pose a threat to the ecological environment. Therefore, pipe detection is the guarantee for the security work.The traditional pipe detection methods that are all single position measurements tend to be too slow to detect the distance pipes. A new detection using ultrasonic guided waves was applied to detect pipeline. The fundamental of pipes ultrasonic inspection technique is inspiring and receiving a guided wave signal in the end of the pipe. Then the analysis of the received signals can determine the location of the pipeline defects and the degree of the defects.In this paper, the ultrasonic guided wave detection was investigated using numerical simulation and experiment methods. The main purpose of this paper is as follows:First it is to clarify the rule of the ultrasonic guided wave propagation in pipeline, then to choose suitable modal for ultrasonic guided wave detection; Second the important influential factor of guided wave detection was analyzed by numerical simulation technology; Third is to build experimental platform of pipeline ultrasonic guided wave detection combining with the numerical simulation results. These results can provide technical support and guidance for creating the machine for ultrasonic guided wave testing.Based on above-mentioned purpose, the works of this article were included:Firstly, the background and significance of pipeline guided wave testing research was analyzed in this paper, and the research situation in ultrasonic guided wave testing field was summarized. Secondly, the basic concept of guided wave and theoretical knowledge was introduced, then the hollow tubular ultrasonic guided wave theory was summarized, the longitudinal, the torsion and the flexural guided wave modal in pipe were analyzed. Thirdly the choice of the guided wave mode for pipeline detection was discussed. Then the numerical simulation of guided wave testing for pipeline was mainly provided by finite element software ANSYS. The different modal, different frequencies, different for different periods of guided wave on the different diameter, wall thickness and different size of the pipeline detection were simulated and investigated in detail. On the basis of these results, the influence of the wall thickness, the size, defects of the pipe and the guided wave modal, frequency, periods to guided wave pipeline detection the article was analyzed. These results can provide guidance for experiment study and practical application. Finally, in order to verify the accuracy of the numerical simulation, a set of experimental system is building, and then using it verifies some result of numerical simulation. Comparison of the numerical simulation and experimental detection result, these results were very consistent.In addition, a prototype system for using ultrasonic guided wave detection pipeline based on the basic of principle was developed, which can be used in laboratory testing. Then the pipeline was detected by this system. The obtained results and the numerical simulation results were very consistent.