Application Of Propagation Properties And Crack Detection Of Guided Wave In Bending Rods

Compared with the traditional method of ultrasonic testing,guided wave as an excitation、long-distance transmission,has the advantages of large detection range of interest for ultrasonic testing personnel.At present,the,straight circular tube and rod guided wave detection were more frequently in the domestic and foreign, bending circular rod or pipe is often encountered in practical engineering.Understanding the propagation characteristics of guided wave in circular rod for the scattering of guided wave in defects has important guiding meaning for the detection of such material and workpiece.In this paper,the method combining finite element numerical simulation and experimental test were apply to the application research of propagation characteristics and defect detection in bending circular rod. in guiding of elastic wave theory.first of all,using the finite element software ABAQUS to establish the numerical model of the bending circular rod,inspired L(0,1) modal based on guided wave dispersion curves and wave structure features in circular rod..the echo waveform and wave field snapshot can be seen that the L(0,1) modal guided wave has mode conversion and produced F(1,1)modal guided wave when through the elbow.Secondly,establish the three-dimensional finite element modal of bending circular rod based on ABAQUS software,the study of the propagation characteristics of guided wave in the same bending angle, ifferent bending radius and the same bending radius,different bending angle.based on the above,for the defect ultrasonic guided wave detection in bending circular rod using numerical simulation,research of dispersion characteristics and transmission characteristics in the circumferent-Ial defect 、 depth defect 、axial defect and groove shaped defect in four aspects,obtain the relation curve of the corresponding defects size and relation amplitude,provided the foundation for quantitative and positioning for the defect detection.Finally,carried out 30°,60°,90°ultrasonic guided wave experimental testing study of the bending circular rod,the center frequency of 100 k Hz longitudinal mode L(0,1)modal guided wave as a detection signal.