Ultrasonic Guided Waves Based Nondestructive Testing And Simulation Study Of 45# Steel Pipe Defects

Being the world's leading steel pipe exporter,steel pipe has enormous contribution to the development of national economy,far better than the other steel products.And 45#steel pipes can obtain good comprehensive performance by modulation processing,playing an important role in fluid transportation and structural components.As the growth of the 45#steel pipe age,the installation defects,environmental corrosion,man-made destruction as well as the other issues will be-gradually exposed,and these problems seems to evolve into a serious accident.At present,China's steel pipe after using for a long time,has entered frequent accident period,so it is important to determine pipeline detection and location.In this paper,the commonly used 45#steel pipe is considered as the object to solve detection problem of 45#steel pipe defects,on the basis of the finite element method and the ultrasonic guided wave technology,mainly includes:set up a simulation model for the ultrasonic guided wave testing,and come forward location index,energy index and waveform index to optimize the simulation parameters;establish the ultrasonic guided wave detection platform achieve the excitation and reception of multi modal guided waves;discuss attenuation properties of guide wave in the pipeline,analysis of defect detection and location accuracy,and further discuss the influence of position,defect forms and defect depth on the positioning accuracy;research interactive process of multi modal with defects,and establish the corresponding relationship between the defect echoes and the three-dimensional characteristics,to provide theoretical guidance for the defect quantification,The results show that:Ultrasonic waveguide technology can be used to detect and locate defects in pipes,such as macro-cracks,annular notchs,and holes.The defect location has a large effect on location accuracy,and the defect type and depth have little effect on location accuracy.In the detection process,the echo signal contains the 3d feature information of the defect.The axial length of the defect mainly affects the shape of the defect echo,and the main energy of the echo isThe combination of simulation and experiment to conduct detection and localization research can greatly improve efficiency.The characteristics evaluation indexes introduced in the simulation model can be optimized to realize the accuracy and reliability of the model.The signal-noise ratio can be improved by the distribution of the piezoelectric plates with symmetrical distribution.In addition,different modes of ultrasonic waveguides have diverse sensitivity to the defects of the pipeline.The L mode is more accurate than the T mode in terms of detection axis.In practical application,a suitable modal waveguide should be chosen for accurate detection of different defects.