激光超声时频参数对裂纹试件的温度检测  

Temperature Measurement of Crack Specimen Based on Laser Ultrasonic Time and Frequency Parameters

作　　者：何力 郭华玲 郑宾 刘辉 贾庸斌 HE Li;GUO Hualing;ZHENG Bin;LIU Hui;JIA Yongbin(School of Electrical and Control Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学电气与控制工程学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2024年第4期539-549,共11页Journal of North University of China(Natural Science Edition)

基　　金：信息探测与处理重点实验室基金(ISPT2020-6)。

摘　　要：为了实现对高温工作环境下含表面裂纹试件的温度测量,提出了利用激光超声瑞利波的时、频参数实现表面裂纹试件温度测量的新思路。采用稳态解作为瞬态初始值的温度加载方法,建立了293.15~743.15 K温度范围内结构钢的表面裂纹试件模型,分析了激光超声瑞利波与表面裂纹的相互作用。在时域上,利用瑞利反射、透射波的归一化峰值来定义反射率、透射率这两个时域参数,得出反射率和透射率都与温度成线性增长关系,反射率和透射率随温度的变化率分别为1.45×10^(-3)dB·K^(-1)和2.3×10^(-3)dB·K^(-1);在频域上,提出了瑞利波的小波时频分析(TFA)分布下超声能量强度的特征极值点关系法,得出在特征频率为2.4 MHz时,能量强度的特征极值随温度的线性增长率为2.56×10^(-4)dB·K^(-1);实验分析证明了仿真结果的可行性。时、频域的研究结果结合实验分析表明,利用时、频参数与温度的线性关系和变化率,可实现表面含裂纹的试件的温度测量表征。In order to achieve temperature measurement of specimens with surface cracks in hightemperature working environments,a new approach was proposed to use the time-frequency parameters of laser ultrasonic Rayleigh waves to achieve temperature measurement of surface crack specimens.This article used the steady-state solution as the transient initial value of the temperature loading method to establish a surface crack specimen model of structural steel within the temperature range of 293.15~743.15 K,and analyzed the interaction between laser ultrasonic Rayleigh waves and surface cracks.In the time domain,the normalized peaks of Rayleigh reflection and transmitted waves were used to define the two time-domain parameters of reflectivity and transmittance,and it was found that both reflectivity and transmittance increase linearly with temperature,and the change rates of reflectivity and transmittance with temperature were 1.45×10^(-3)dB⋅K^(-1)and 2.3×10^(-3)dB⋅K^(-1),respectively;In the frequency domain,the characteristic extreme point relationship method of ultrasonic energy intensity under the wavelet TFA(time-frequency analysis)distribution of Rayleigh wave was proposed,and the linear growth rate of the characteristic extreme value of energy intensity with temperature was 2.56×10^(-4)dB⋅K^(-1)when the characteristic frequency was 2.4 MHz;experimental analysis proved the feasibility of simulation results.From the research of time and frequency domains combined with experimental analysis,it is shown that the temperature measurement expression of the specimen with surface crack can be realized by using the linear relationship and change rate of time-frequency parameters and temperature.

关 键 词：激光超声 时频参数 稳态解 温度检测 小波TFA分布 能量强度 

分 类 号：TN249[电子电信—物理电子学]