Impact-Induced Delamination Detection of Composites Based on Laser Ultrasonic Zero-Lag Cross-Correlation Imaging
Impact-Induced Delamination Detection of Composites Based on Laser Ultrasonic Zero-Lag Cross-Correlation Imaging
复制标题
DOI：
10.1155/2016/6474852
复制
发表时间：
2016-10
影响因子：
--
通讯作者：
Y. An
中科院分区：
文献类型：
--
作者：
Y. An
本文提出了通过使用完全非接触式激光扫描超声波场计算的零滞后互相关（ZLCC）成像来实现冲击引起的分层可视化。所提出的技术能够即时可视化复合材料的不可见分层，而无需安装任何传感器。此外，它提供了可靠的损伤诊断，无需与从目标结构未损坏状态获得的基线数据进行比较，从而可以最大限度地减少误报。首先，通过有限元分析证明了内部分层引起的驻波的存在。然后，展示了 ZLCC 如何从测量的超声波场中仅物理隔离和可视化驻波特征。为了通过实验验证所提出的技术，引入了完全非接触式激光超声成像系统，并通过激光扫描石墨纤维复合板来可视化内部分层。实验结果表明，隐藏分层成功地自动可视化和量化，无需任何用户干预。
This paper presents impact-induced delamination visualization by zero-lag cross-correlation (ZLCC) imaging computed using fully noncontact laser scanned ultrasonic wavefields. The proposed technique enables instantaneous visualizing of invisible delamination of composite materials without any sensor installation. Moreover, it provides robust damage diagnosis without comparing with baseline data obtained from the undamaged condition of a target structure, making it possible to minimize false alarms. First, the existence of internal delamination-induced standing waves is proven by employing a finite element analysis. Then, how ZLCC can physically isolate and visualize only the standing wave feature from the measured ultrasonic wavefields is shown. To experimentally validate the proposed technique, a fully noncontact laser ultrasonic imaging system is introduced, and the internal delamination is visualized by laser scanning in a graphite fiber composite plate. The experimental results reveal that hidden delamination is successfully and automatically visualized and quantified without any users’ intervention.