Nonlinear circumferential ultrasonic wave guiding method for damage evaluation of metal round tube

Abstract

The invention provides a nonlinear circumferential ultrasonic wave guiding method for damage evaluation of a metal round tube. The nonlinear circumferential ultrasonic wave guiding method comprises the following steps of calculating a phase velocity dispersion curve according to physical parameters and geometric parameters of a metal round tube specimen to be measured; fatigue loading: loading to a scheduled cycle according to a scheduled plan to obtain a normalization value beta; repeatedly loading until fatigue loading is performed on a final scheduled cycle, and measuring a relation curve that a nonlinear acoustic parameter beta of circumferential ultrasonic wave guiding changes along with a load cycle index M; obtaining a damage degree under given loading conditions according to the beta-M relation curve. The nonlinear circumferential ultrasonic wave guiding method provided by the invention has the beneficial effects that a whole round tube member is covered by adopting nonlinear circumferential ultrasonic wave guiding detection, so that a damage state of round tube members / materials is effectively detected and evaluated, and a reliable reference is provided for safe use of the round tube members / materials; the nonlinear circumferential ultrasonic wave guiding method has the advantages of high detection speed, low detection cost and high detection accuracy.

Description

technical field [0001] The invention relates to a method for evaluating the damage of a metal circular pipe, in particular to a nonlinear circumferential ultrasonic guided wave method for evaluating the damage of the metal circular pipe. Background technique [0002] Metal round tubes have been widely used in practical engineering fields due to their excellent mechanical properties. The metal round tube will be affected by various external factors in the actual use process. These external factors will act on the metal round tube repeatedly for a long time, which will lead to changes in its mechanical and physical properties, and then make the potential inside the metal round tube Cracks appear at the defect and break, causing major accidents and causing huge economic losses. Therefore, it is particularly necessary and urgent to effectively evaluate the damage state of the circular tube structure. [0003] The principle of traditional ultrasonic (including ultrasonic guided ...

AI Technical Summary

Problems solved by technology

The metal round tube will be affected by various external factors in the actual use process. These external factors will act on the metal round tube repeatedly for a long time, which will lead to changes in its mechanical and physical properties, and then make the potential inside the metal round tube Cracks appear at the defect and break, causing major accidents and causing huge economic losses. Therefore, it is particularly necessary and urgent to effectively evaluate the damage state of the circular tube structure.

[0003] The principle of traditional ultrasonic (including ultrasonic guided wave) detection technology is to evaluate the damage state of materials by detecting information such as sound velocity, sound attenuation and acoustic impedance in materials or structures, and can effectively evaluate materials or structures such as cracks, holes, inclusions, etc. However, it is not sensitive to the degradation of the early mechanical properties of the structure, and the detection speed is slow, which is not conducive to timely and effective detection and evaluation of the damage state of the round tube, and the detection cost is high

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