Helical welded pipe torsion-bending guided wave testing method and device using a helical transducer

Abstract

The invention discloses a method and a device for detecting a torsion-bending guided wave of a spiral welded pipe using a spiral transducer. The guided wave dispersion characteristics of the spiral welded pipe are calculated by the semi-analytical finite element method, and then the frequency and wave velocity of the torsion-bending guided wave of the parallel spiral weld are calculated; the spiral transducer is arranged in a circle along the spiral direction, and is controlled by a guided wave detector The twisted guided wave is excited, propagates along the axial direction of the spiral welded pipe and receives the echo after encountering the reflection of the defect; the position of the defect is determined according to the wave packet of the defect, and the distance of the defect is calculated. The invention eliminates the phenomenon that the spiral weld signal continues to appear in the echo when the traditional ring-shaped integrated magnetostrictive transducer performs guided wave detection, improves the signal-to-noise ratio of the echo, makes the defect signal easy to extract, and improves the spiral seam signal. Reliability of guided wave testing for welded pipes.

Description

technical field [0001] The invention relates to a non-destructive detection method for defects of a spiral welded pipe, in particular to a method and device for detecting a torsion-bending guided wave of a spiral welded pipe using a spiral transducer, and belongs to the technical field of non-destructive detection. Background technique [0002] Spiral welded pipe is a steel pipe made by rolling a steel strip into a tube blank according to a certain helical angle and welding the pipe seam. It has good weldability and crack resistance, and is widely used in long-distance pipelines. During the service process, the spiral welded pipe will be affected by factors such as corrosion and external force damage, resulting in various defects in the spiral welded pipe. If the defects in the spiral welded pipe cannot be found in time, it will lead to the leakage of the long-distance pipeline and endanger the safety of people and property. In order to avoid accidents caused by defects of ...

AI Technical Summary

Problems solved by technology

Since the position of the reinforcement projection of the spiral weld on the cross-section of the pipe is always changing, at any moment when the guided wave of the cylindrically symmetrically distributed wavefront passes through a helical weld with a pitch, the guided wave beam will be at a certain point of the helical weld with the pitch. Reflection occurs at this position, so that the weld signal continues to appear in the echo, resulting in a significant drop in the signal-to-noise ratio of the echo

Images