Experiment on Propagation Characteristics of Ultrasonic Guided Waves in Steel Strands based on Fractured Wires Detection
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摘要: 超声导波技术已被成功应用于钢绞线单处断丝检测。然而，实际工程中钢绞线经常发生多处断丝，使用导波检测时，由于钢绞线结构的特殊性和多处断口的存在，使得导波的传播极为复杂。提出在钢绞线同一根钢丝中制作三处断口，通过设计试验获取不同条件下检测信号的方法来研究导波的传播特性。分析了脉冲信号的衰减和断口回波信号的变化，结果表明：由于钢绞线钢丝之间接触应力的存在，导波遇到某根钢丝中的断口时会发生部分反射，从而降低了导波向前传播的能量；通过断口之后，钢丝之间的能量泄漏使得导波继续在已断钢丝和其他钢丝中同时传播，有利于检测同根钢丝上的其他缺陷。为导波检测钢绞线实际存在的多处断丝奠定了基础。Abstract: The ultrasonic guided wave technology was successfully used for the detection of strands with fractured wires at a single position. However, in practice, wires comprising the strand often fracture in several places. In such a case, the propagation of guided waves was very complicated because of the special structure of the strand and many fractured surfaces. In this paper, a strand with three fractured surfaces in a wire was used as the specimen, and a method was proposed to study propagation characteristics of guided waves by acquiring signals from the strand under different experimental conditions. At last, the attenuation of the passing pulse signals and the change of the defect signals were analyzed. Results show that due to the contact stresses between the wires guided waves propagation in a strand can not be reflected completely when they encounter a fractured surface in a wire. While the forward energy of guided waves decreases, and then waves continue propagating simultaneously in the fractured wire and other wires because of the energy losses between these wires, which is helpful to inspect other defects in the same wire. The conclusion provides a certain foundation for application of guided waves technology to detect the strand with fractured wires in different places.
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[1] Keith A B, Chris D, Kwun H. Nondestructive evaluation of prestressing strands with magnetostrictive sensors[J]. Proceedings of SPIE,1998(3400):326-337. [2] XU Jiang, WU Xin-jun, WANG Liang-yun, et al. Detecting the flaws in prestressing strands using guided waves based on the magnetostrictive effect[J]. Insight,2007,49(11):647-650. [3] Rizzo P, Lanza di Scalea F. Wave propagation in multi-wire strands by wavelet-based laser ultrasound[J]. Society for Experimental Mechanics,2004,44(4):407-415. [4] Bartoli I, Marzani A, Lanza di Scalea F, et al. SAFE modeling of waves for the Structural Health Monitoring of Prestressing tendons[J]. Proceedings of SPIE,2007(65320D):1-10. [5] 武新军，徐江，沈功田.非接触式磁致伸缩导波管道无损检测系统的研制[J].无损检测,2010,32(3):166-170. [6] 邹君，武新军，徐江，等.基于杜芬混沌振子的磁致伸缩导波信号识别[J].无损检测,2008,30(9):600-602. [7] Kwun H, Keith A B, Hanley J J. Effects of tensile loading on the properties of elastic-wave propagation in a strand[J]. Journal of the Acoustical Society of America,1998,103(6):3370-3375. [8] Lanza di Scalea F, Rizzo P, Seible F, et al. Stress measurement and defect detection in steel strands by guided Stress waves[J]. Journal of Materials in Civil Engineering,2003,15(3):219-227.
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