提出了一种基于匀速方波路径的激光连续扫描多普勒测试方法,以实现含任意矩形缺孔的平板结构工作变形的测量。首先,结合对测试精度与时间的需求,选择合适的线分辨率和方波分辨率,规划得到首尾相连且覆盖结构表面的方波路径;然后控制激光沿着扫描路径进行匀速的多周期连续扫描并采集时域信号,对时域信号进行延迟优化等处理即可得到结构的工作变形;最后以带有两个任意矩形缺孔的平板结构为例进行了方波路径下激光连续扫描测试试验,并将其结果与SLDV结果和仿真计算结果进行对比,MAC值均大于0.95,验证了方法的有效性。该方法可实现含有任意矩形孔的平板结构的连续扫描激光振动测试,不仅具有高效率、测点密集等优点,而且可以根据需求对局部分辨率进行调整,对进一步提高其工程应用范围,具有重要作用。
Abstract
A continuous scanning laser Doppler testing method based on the square wave path and uniform scanning is proposed to measure the Operational Deflection Shape(ODS) of a flat plate structure with arbitrary rectangular holes. Firstly, according to the demand for test accuracy and time, the appropriate line resolution and square wave resolution are selected to plan the square wave path which is connected from end to end and cover the surface of the structure. Then, the working deformation of the structure can be obtained by controlling the laser to scan uniformly and continuously along the scanning path and collecting the time domain signals. The time domain signals are optimized by the delay optimization technique. Finally, taking a flat plate structure with two arbitrary rectangular holes as an example, the continuous scanning laser Doppler vibrometry (CSLDV) is carried out under the square wave path. The obtained results are correlated with these from the SLDV method and simulation respectively. The MAC values of the compared mode shapes are all greater than 0.95. It is verified the effectiveness of the proposed method. It is also indicated the ODS measurement of a plate structure with arbitrary rectangular holes using the CSLDV method, which not only has the advantages of high efficiency and dense measuring points, but also can adjust the local resolution according to the demand. This approach plays an important role in further improving the scope of engineering application.
关键词
矩形缺孔 /
匀速连续扫描 /
激光多普勒 /
方波路径
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Key words
rectangular hole /
constant speed continuous scanning /
laser Doppler /
square wave path
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脚注
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