Putkis O, Dalton R P, Croxford A J
Ultrasonics and NDT group, University of Bristol, Bristol BS8 1TR, UK; QinetiQ plc, Farnborough GU14 0LX, UK.
QinetiQ plc, Farnborough GU14 0LX, UK.
Ultrasonics. 2016 Feb;65:390-9. doi: 10.1016/j.ultras.2014.11.013. Epub 2014 Dec 1.
Ultrasonic guided wave propagation in anisotropic attenuative materials like CFRP (carbon fibre reinforced polymer) is much more complicated than in isotropic materials. Propagation phenomena need to be understood and quantified before reliable NDE (Non-destructive Evaluation)/SHM (Structural Health Monitoring) inspection systems can be realized. The propagation characteristics: energy velocity, dispersion, mode coupling, energy focusing factor and attenuation are considered in this paper. Concepts of minimum resolvable distance and sensitivity maps are extended to anisotropic attenuative materials in order to provide the means for comparison of different guided wave modes in composite materials. The paper is intended to serve as a framework for evaluating and comparing different modes and choosing the optimum operating conditions (frequency, sensor layout) for possible NDE/SHM applications on composite materials. Fundamental guided wave modes in the low frequency regime for highly anisotropic CFRP plates are investigated experimentally and theoretically and the implications for NDE/SHM are discussed.
超声导波在诸如碳纤维增强聚合物（CFRP）等各向异性衰减材料中的传播比在各向同性材料中要复杂得多。在实现可靠的无损检测（NDE）/结构健康监测（SHM）检测系统之前，需要理解并量化传播现象。本文考虑了传播特性：能量速度、频散、模式耦合、能量聚焦因子和衰减。最小可分辨距离和灵敏度图的概念被扩展到各向异性衰减材料，以便为比较复合材料中不同导波模式提供手段。本文旨在作为一个框架，用于评估和比较不同模式，并为复合材料上可能的无损检测/结构健康监测应用选择最佳操作条件（频率、传感器布局）。对高度各向异性CFRP板在低频范围内的基本导波模式进行了实验和理论研究，并讨论了其对无损检测/结构健康监测的影响。
