Sheng Zhipeng, Chen Bing, Hu Wenxin, Yan Keyu, Miao Hong, Zhang Qingchuan, Yu Qifeng, Fu Yu
Opt Express. 2021 Aug 30;29(18):28134-28147. doi: 10.1364/OE.436196.
Vibration measurement, particularly mode shape measurement, is an important aspect of structural dynamic analysis since it can validate finite element or analytical vibration models. Scanning laser Doppler vibrometry (LDV) and high-speed digital image correlation have become dominant methods for experimental mode shape measurement. However, these methods have high equipment costs and several disadvantages regarding spatial or temporal performance. This paper proposes a laser Doppler vibrometer induced stroboscopic digital image correction for non-contact mode shape and operational deflection shape measurement. Our results verify that single-point LDV and normal rate cameras can be used obtain high spatial resolution mode shape and operational deflection shape. Measurement frequency range is much higher than the camera capturing rate. We also show that the proposed approach coincides well with time-averaged electronic speckle pattern interferometry.
振动测量，尤其是振型测量，是结构动力学分析的一个重要方面，因为它可以验证有限元或解析振动模型。扫描激光多普勒测振仪（LDV）和高速数字图像相关技术已成为实验振型测量的主导方法。然而，这些方法设备成本高，在空间或时间性能方面存在若干缺点。本文提出一种用于非接触式振型和运行挠度形状测量的激光多普勒测振仪诱导频闪数字图像校正方法。我们的结果验证了单点LDV和普通帧率相机可用于获取高空间分辨率的振型和运行挠度形状。测量频率范围远高于相机捕捉速率。我们还表明，所提出的方法与时间平均电子散斑图案干涉测量法非常吻合。
