管道导波无损检测频率选择与管材特征关系  

Relationship between Frequency Selection and Pipe Characteristics for Guided Waves NDT

作　　者：王悦民[1] 沈立华[1] 申传俊[1] 孙丰瑞[1] 

机构地区：[1]海军工程大学船舶与动力学院,武汉430033

出　　处：《机械工程学报》2009年第8期243-248,共6页Journal of Mechanical Engineering

基　　金：中国博士后科学基金(20060390865);湖北省自然科学基金(2007ABA224)资助项目

摘　　要：选取合适的导波激励频率在导波无损检测工程应用中具有重要实用意义。分别讨论L(0,1)和L(0,2)模态导波在管道中存在截止频率现象,给出相应截止频率计算公式,并研究L(0,1)和L(0,2)导波截止频率分别随管道直径和壁厚变化关系。通过选择不同的激励频率,对一给定的钢管进行试验检测。结果表明:随着管道直径的增大,L(0,1)导波低通截止频率和L(0,2)导波高通截止频率都随之减小;随着管道壁厚的增大,L(0,1)导波低通截止频率和L(0,2)导波高通截止频率开始时都随之增大,但增大的幅度慢慢变小,当管径达到一定值时,两者的截止频率与管道的壁厚变化无关;管道导波检测激励频率选择的理论计算和试验结果相互一致。Selecting proper guided wave exciting frequency is of important practical significance in the engineering application of guided wave non-destructive testing （NDT）. The characteristic of guided wave propagation in pipes that L（0, 1） and L（0, 2） have a cutoff frequency are respectively discussed, and the calculation formulas o f their cutoff frequency are given. The varied relationship between the cutoff frequency of L（0, 1） and L（0, 2） mode guide waves, the outer diameter and wall thickness of pipes are discussed respectively. For a given steel pipe, experiments are carried out by selection of different exciting frequency. The results show that the ＂low-pass＂ type cutoff frequency of L（0, 1） and ＂high-pass＂ type cutoff frequency of L（0, 2） are reduced with the increase of outer diameter of pipes, and the ＂low-pass＂ type cutoff frequency of L（0, 1） and ＂high-pass＂ type cutoff frequency of L（0, 2） initially increase with the increase of wall thickness of pipes, but the increased amplitude decreases slowly. When the outer diameter of pipes attains a certain value, both of the cutoff frequencies are irrelevant to wall thickness of pipes. The experimental results are in agreement with theoretical computation of selected exciting frequency for guided wave NDT of pipes.

关 键 词：无损检测 磁致伸缩传感器 导波 频散 管道 

分 类 号：TG115.28[金属学及工艺—物理冶金]