高阶纵向超声导波在钢绞线缺陷检测中的应用研究  

APPLICATION STUDY ON DEFECT DETECTION IN STEEL STRANDS BY USING HIGH-ORDER ULTRASONIC LONGITUDINAL GUIDED WAVES

作　　者：刘增华[1] 赵继辰[1] 吴斌[1] 何存富[1] 

机构地区：[1]北京工业大学机械工程及应用电子技术学院,北京100124

出　　处：《工程力学》2011年第4期214-220,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(10602004;50975006);北京市自然科学基金项目(2072003);北京市科技新星计划项目(2008A015);北京市优秀人才培养项目(20081B0501500173);北京市教委项目(KM201010005003)

摘　　要：为了实现对钢绞线的主动健康监测,采用安装在结构外表面上的磁致伸缩传感器激励和接收高阶纵向超声导波,优化各种参数以用于缺陷的识别和评估。实验选取经Hanning窗调制的正弦脉冲信号在7芯钢绞线中激励中心频率0.86MHz的高阶纵向超声导波L(0,2)模态,用于在两根钢绞线外围钢丝和中心钢丝中人工缺陷的检测。实验分析了L(0,2)模态对不同钢丝中的缺陷敏感程度,并进一步研究了缺陷深度和激励信号周期数对接收到的导波信号幅度的影响。实验结果表明,利用磁致伸缩传感器激励频率0.86MHz的L(0,2)模态可以用于钢绞线中的缺陷检测,对钢绞线外围钢丝的检测能力优于中心钢丝,并且缺陷回波的幅度可实现对缺陷大小的表征。同时,激励信号周期数的优化对高阶纵向超声导波用于钢绞线的缺陷检测显得十分重要。In order to achieve active health monitoring of steel strands,magnetostrictive transducers fixed on the surface of the structures are applied for the excitation and the reception of high-order ultrasonic longitudinal guided wave modes and proper parameters are optimized for the identification and evaluation of the defects.The sinusoidal tone burst modulated by a Hanning window is used for an exciting high-order ultrasonic longitudinal guided wave mode L（0,2） at 0.86MHz in seven-wire steel strands to detect artificial defects machined in the helical and center wires in two pieces of steel strands separately.The sensitivity of L（0,2） mode to defect detection in different wires of steel strands is analyzed experimentally,and furthermore the effects of the defect depth and the cycles of excitation signals on the amplitudes of received guided wave signals are researched.Experimental results show that the L（0,2） mode at 0.86MHz can be used for the defect detection in the steel strand with the help of magnetostrictive transducers while the mode is more sensitive to the defects in helical wires than in central wires of steel strands,and furthermore the defect characterization can be achieved based on the amplitudes of received echoes.Simultaneously,it is important for the defect detection in steel strands to optimize the cycle number of the excitation signal by using high-order ultrasonic longitudinal guided waves.

关 键 词：超声导波 高阶模态 钢绞线 缺陷 激励信号 

分 类 号：TB132[理学—物理] TB559[理学—应用物理]