ISSN 1004-4140
CN 11-3017/P

LFM信号检测混凝土缺陷研究

李长征, 师芳芳, 吴何珍

李长征, 师芳芳, 吴何珍. LFM信号检测混凝土缺陷研究[J]. CT理论与应用研究, 2014, 23(1): 19-26.
引用本文: 李长征, 师芳芳, 吴何珍. LFM信号检测混凝土缺陷研究[J]. CT理论与应用研究, 2014, 23(1): 19-26.
LI Zhang-zheng, SHI Fang-fang, WU He-zhen. Research on Inspecting Concrete Flaws with LFM Signal[J]. CT Theory and Applications, 2014, 23(1): 19-26.
Citation: LI Zhang-zheng, SHI Fang-fang, WU He-zhen. Research on Inspecting Concrete Flaws with LFM Signal[J]. CT Theory and Applications, 2014, 23(1): 19-26.

LFM信号检测混凝土缺陷研究

基金项目: 

41104117)

水利部行业公益性(201301061)

国家自然科学基金(11074273

详细信息
    作者简介:

    李长征(1978—),男,博士,主要从事声学检测的研究工作,Tel:0371-66028521,E-mail:hnlzl@163.com

    通讯作者:

    李长征(1978—),男,博士,主要从事声学检测的研究工作,Tel:0371-66028521,E-mail:hnlzl@163.com

  • 中图分类号: TU459

Research on Inspecting Concrete Flaws with LFM Signal

  • 摘要: 针对超声混凝土缺陷检测信噪比低、穿透深度浅的问题,提出利用线性调频(LFM)信号检测混凝土缺陷。通过在发射端发射时宽和带宽的积大于1的LFM信号,在接收端将回波脉冲压缩,得到主瓣较窄,信噪比较高的压缩信号。理论分析了换能器带宽对压缩效果的影响。数值计算结果表明,在一定幅度的噪声存在条件下,回波信号经过脉冲压缩后仍能够得到好的压缩效果。实际检测结果表明,压缩后的LFM信号较压缩前检测信号明显提高了信噪比。
    Abstract: On account of existing problems of ultrasonic inspecting concrete defect,such as low signal noise ratio(SNR) and limited penetrating depth,the method of exciting with LFM is put forward.Linear frequency modulation(LFM) signal with the characteristics of long time series and wide band width is excited at transmitting terminal,and compressed signal with narrower main lobe and higher SNR will be obtained at receiving terminal through compression method.The effect of transducer's bandwidth is analyzed.The results of numerical calculation show that good compressed results of echo will be obtained if there is much noise.Testing results show that pulse compression method can improve signal-noise ratio.
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出版历程
  • 收稿日期:  2013-01-13
  • 网络出版日期:  2022-12-09

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