利用Duffing系统周期跳跃的弱超声导波识别  

Weak guided wave signal detection by using period jumping of DufRng system

作　　者：张伟伟 成梦菲[3] 赵子龙 ZHANG Weiwei;CHENG Mengfei;ZHAO Zilong(Dongguan University of Technology,School of Mechanical Engineering,Dongguan,523808;Mechanic Department,Taiyuan University of Science&Technology,Taiyuan,030024;College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan,030024)

机构地区：[1]东莞理工学院机械工程学院,东莞523808 [2]太原科技大学力学系,太原030024 [3]太原理工大学机械与运载工程学院,太原030024

出　　处：《声学学报》2021年第4期605-613,共9页Acta Acustica

基　　金：国家自然科学基金项目(11872261);山西省自然科学基金项目(201801D121012);晋城科技项目预研项目(20198035)资助。

摘　　要：在超声导波检测中,由小缺陷产生的弱回波信号有可能淹没在噪声信号中从而造成漏检风险,通过分析Duffing系统随策动力幅值变化的分岔特性,获得了系统发生周期跳跃的临界状态,将与策动力同频率的弱回波信号作为干扰项叠加到Duffing系统临界状态中,相当于改变了策动力的幅值,从而引起临界状态的周期跳跃,依据系统的周期跳跃实现了弱超声导波回波信号的识别.进一步研究发现,超声导波导致策动力幅值增加或减小取决于截取信号与策动力的相位差,且两者之间互为异相位,同周期内近似相差π。以此构造了小尺度周期态和大尺度周期态两种检测模型,并利用仿真信号和实验信号检验了检测模型识别弱导波信号的有效性,同时对比了两种检测模型的抗噪声干扰能力,结果表明小尺度周期态检测模型具有结果唯一、抗噪声能力强的优点,该方法可有效的提高超声导波检测小缺陷的灵敏度.A potential risk of ultrasonic guided wave testing must be noticed,which the weak echo signal from the small defect may be submerged in the noise signal and cause missed detection.By analyzing the bifurcation characteristics of the Duffing system with the amplitude of the driving force,the critical state of the system periodic jumping can be obtained.The ultrasonic guided wave signal with same frequency as the driving force is added into Duffing system as the disturbance term of the driving force.This is equivalent to changing the amplitude of the driving force,which will cause the periodic jumping.The guided wave signal can be identified according to the periodic jumping.The increases or decreases of the driving force amplitude with the interference of the guided wave signal heavily depends on the phase between the intercepted signal and the periodic driving force.The phases satisfying the conditions of the increase and decrease of the driving force are out of phase with each other,whose difference is approximately n in the same period.Based on these conclusion,two detection models of small-scale periodic state and large-scale periodic state are constructed,and the effectiveness of the models is checked for identifying the guided wave signal by numerical and experimental studies.At the same time,the anti-noise interference ability of the two models are compared.The results show that the small-scale periodic state detection model has the advantages of unique results and strong anti-noise ability.This method can effectively improve the sensitivity of ultrasonic guided wave detection of small defects.

关 键 词：DUFFING系统 超声导波 临界状态 策动力 检测模型 抗噪声干扰 模型识别 抗噪声能力 

分 类 号：TB551[理学—物理]