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第 38 卷 第 5 期                                                                       Vol. 38, No. 5
             2019 年 9 月                          Journal of Applied Acoustics                 September, 2019

             ⋄ 研究报告 ⋄



                    扩散场重建格林函数检测钢轨近表面缺陷                                                             ∗





                                     张海燕     1†    刘建全     1   张 辉     1,2  徐梦云      1



                                            (1 上海大学通信与信息工程学院        上海   200444)
                                         (2 上海工程技术大学城市轨道交通学院           上海   201620)

                摘要    利用超声相控阵全矩阵捕获功能获取后期时间的扩散场信息，实现钢轨近表面缺陷成像。对扩散场信
                号进行互相关，重建阵元之间的格林函数，获取阵元之间未延时的响应，恢复被噪声湮没的早期缺陷信息，将
                波数成像方法用于近表面缺陷的快速成像。采用两种超声相控阵探头在钢轨表面采集实验数据，说明格林函
                数恢复效果与相控阵阵元的个数和激励频率有关。实验结果清晰地显示了距钢轨表面 5 ∼ 10 mm 处的缺陷，
                证实了互相关方法重建格林函数对近表面缺陷检测的有效性。
                关键词     扩散场，格林函数，互相关，近表面缺陷
                中图法分类号: O429           文献标识码: A          文章编号: 1000-310X(2019)05-0774-08
                DOI: 10.11684/j.issn.1000-310X.2019.05.003






                      Diffusion field reconstruct Green’s function to detect near-surface
                                                    defects of rails



                             ZHANG Haiyan   1  LIU Jianquan 1  ZHANG Hui   1,2  XU Mengyun 1

                      (1 School of Communication & Information Engineering, Shanghai University, Shanghai 200444, China)

                  (2 School of Urban Railway Transportation, Shanghai University of Engineering Science, Shanghai 201620, China)

                 Abstract  The full-matrix capture of the ultrasonic phased array is used to obtain the diffusion field infor-
                 mation at the later time to realize the near-surface defect imaging of the rail. The cross-correlation of the
                 diffused field signals is performed to reconstruct the Green’s function between the array elements, to obtain
                 the undelayed response between the array elements, and recover the early defect information submerged by the
                 noise, then wavenumber imaging method is used to achieve rapid imaging of near-surface defects. Two kinds of
                 ultrasonic phased array probes are used to collect experimental data on the surface of the rail, indicating that
                 the Green’s function recovery is related to the number of phased array elements and the excitation frequency.
                 The experimental results clearly show the defect from 5 mm to 10 mm from the surface of the rail, which
                 confirms the effectiveness of the cross-correlation method to reconstruct the Green’s function for the detection
                 of near-surface defects.
                 Key words Diffusion field, Green’s function, Cross-correlation, Near-surface defects


             2018-11-22 收稿; 2019-03-08 定稿
             国家自然科学基金项目 (11874255, 11674214)
             ∗
             作者简介: 张海燕 (1970- ), 女, 山东曹县人, 博士, 教授, 研究方向: 超声检测。
             † 通讯作者 E-mail: hyzh@shu.edu.cn
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