钢花管中低频纵向超声导波传播特性的试验研究  

EXPERIMENT RESEARCH ON PROPAGATION CHARACTERISTICS OF LOW FREQUENCY ULTRASONIC LONGITUDINAL GUIDED WAVES IN STEEL FLORAL PIPES

作　　者：吴斌[1] 颉小东[1] 李昱昊[1] 刘增华[1] 何存富[1] 谢伟达[2] 

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 [2]香港城市大学制造工程与维护管理系

出　　处：《工程力学》2012年第8期319-324,332,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(50975006;10772009;10972014);NSFC-RGC联合资助项目(60831160523);北京市自然科学基金项目(1122007);北京市教委项目(KM201010005003);北京市科技新星计划项目(2008A015)

摘　　要：钢花管是管棚支护结构中的核心承力构件。将超声导波技术应用于钢花管的无损检测显得十分重要。首先优化选取了适用于钢花管检测的压电陶瓷片尺寸以及激励频率为30kHz的L(0,2)模态。为研究钢花管管体上的孔对低频纵向超声导波检测能力的影响,试验研究了钢花管孔数与检测信号特征之间的变化关系。结果表明:钢花管孔数的增加对频率为30kHz的L(0,2)模态回波信号幅值几乎没有影响,表明低频纵向超声导波具有对长距离钢花管无损检测的潜力;而频率为30kHz的L(0,2)模态的群速度随钢花管管体中孔的增加呈线性下降的趋势。该研究结果为基于低频超声导波技术的钢花管无损检测奠定了一定的基础。A steel floral pipe is a key load-carrying member of pipe supporting structures. It is important to apply ultrasonic guided wave technique to nondestructive testing of steel floral pipes. Firstly, the dimensions of PZT elements are optimized for the inspection of steel floral pipes and the excitation frequency of L（0,2） mode at 30kHz. In order to investigate the effects of the holes in steel floral pipes on the inspection ability of this low frequency ultrasonic longitudinal guided wave mode, the relation between the number of holes and the characteristics of received inspection signals are obtained from experimental research. Research results indicate that the holes in a steel floral pipe have almost little effect on the peak-to-peak amplitudes of L（0,2） mode at 30kHz. As a result, it is shown that low frequency longitudinal guided waves have potentials to inspect long range steel floral pipes nondestructively. Furthermore, group velocity of L（0,2） mode at 30kHz tends to decrease linearly with the increase of the holes on steel floral pipes. These research results provide a basis for nondestructive inspection of steel floral pipes based on ultrasonic guided waves in low frequency range.

关 键 词：超声导波 钢花管 孔 幅度 群速度 

分 类 号：TH878[机械工程—仪器科学与技术] TB551[机械工程—精密仪器及机械]