Mei Hanfei, Migot Asaad, Haider Mohammad Faisal, Joseph Roshan, Bhuiyan Md Yeasin, Giurgiutiu Victor
Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, USA.
Department of Mechanical Engineering, College of Engineering, Thi-Qar University, Nasiriyah 64001, Iraq.
Sensors (Basel). 2019 Apr 11;19(7):1734. doi: 10.3390/s19071734.
This paper presents a new methodology for detecting and quantifying delamination in composite plates based on the high-frequency local vibration under the excitation of piezoelectric wafer active sensors. Finite-element-method-based numerical simulations and experimental measurements were performed to quantify the size, shape, and depth of the delaminations. Two composite plates with purpose-built delaminations of different sizes and depths were analyzed. In the experiments, ultrasonic C-scan was applied to visualize the simulated delaminations. In this methodology, piezoelectric wafer active sensors were used for the high-frequency excitation with a linear sine wave chirp from 1 to 500 kHz and a scanning laser Doppler vibrometer was used to measure the local vibration response of the composite plates. The local defect resonance frequencies of delaminations were determined from scanning laser Doppler vibrometer measurements and the corresponding operational vibration shapes were measured and utilized to quantify the delaminations. Harmonic analysis of local finite element model at the local defect resonance frequencies demonstrated that the strong vibrations only occurred in the delamination region. It is shown that the effect of delamination depth on the detectability of the delamination was more significant than the size of the delamination. The experimental and finite element modeling results demonstrate a good capability for the assessment of delamination with different sizes and depths in composite structures.
本文提出了一种基于压电晶片有源传感器激励下的高频局部振动来检测和量化复合材料板分层的新方法。进行了基于有限元方法的数值模拟和实验测量，以量化分层的尺寸、形状和深度。分析了两块具有不同尺寸和深度的特制分层的复合材料板。在实验中，采用超声C扫描来可视化模拟分层。在该方法中，压电晶片有源传感器用于1至500kHz线性正弦扫频的高频激励，扫描激光多普勒测振仪用于测量复合材料板的局部振动响应。分层的局部缺陷共振频率由扫描激光多普勒测振仪测量确定，并测量相应的工作振动模态以量化分层。在局部缺陷共振频率下对局部有限元模型进行谐波分析表明，强振动仅发生在分层区域。结果表明，分层深度对分层可检测性的影响比分层尺寸更为显著。实验和有限元建模结果表明，该方法对评估复合材料结构中不同尺寸和深度的分层具有良好的能力。
