Abstract Guided wavefields in composite structures carry a wealth of information about wavefield anomalies from damage–wave interactions. Although such anomalies can be used for damage detection, they are easily masked by incident waves from actuators and reflected waves from structural boundaries. This research presents a concept of guided wavefield curvature for the detection of structural damage. Wavefield curvature analysis is able to highlight the amplitudes of local anomalies in the wavefield signals associated with damage. A wavefield curvature imaging algorithm is developed for visualizing invisible damage in composite structures. The algorithm is first verified by detecting delamination in a carbon fiber reinforced polymer (CFRP) plate and then applied for detection of debonding in a honeycomb sandwich panel. In the experiments, wavefields are generated by a PZT transducer and are then registered by a scanning laser Doppler vibrometer. The experimental results accord well with the actual locations, sizes, and shapes of the delamination and debonding, confirming the effectiveness of the proposed algorithm for the detection of invisible damage in composite structures.

中文翻译：

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复合结构中不可见损伤的引导波场曲率成像

摘要 复合结构中的导波场携带着大量关于损伤-波相互作用引起的波场异常的信息。尽管此类异常可用于损伤检测，但它们很容易被来自致动器的入射波和来自结构边界的反射波掩盖。本研究提出了用于检测结构损坏的导波场曲率概念。波场曲率分析能够突出与损坏相关的波场信号中局部异常的幅度。开发了一种波场曲率成像算法，用于可视化复合结构中的不可见损伤。该算法首先通过检测碳纤维增强聚合物 (CFRP) 板中的分层来验证，然后应用于检测蜂窝夹芯板中的脱粘。在实验中，波场由 PZT 换能器产生，然后由扫描激光多普勒测振仪记录。实验结果与实际脱层和脱粘的位置、尺寸和形状非常吻合，证实了该算法在复合结构无形损伤检测中的有效性。