Continuous scanning laser Doppler vibrometry method for ODS measurements of flat plate structure with arbitrary rectangular holes

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Journal of Vibration and Shock ›› 2023, Vol. 42 ›› Issue (19) : 172-179.

ZHANG Lei1, ZANG Chaoping1, WANG Qi2, CHEN Xiang2

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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.

Key words

rectangular hole / constant speed continuous scanning / laser Doppler / square wave path

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ZHANG Lei1, ZANG Chaoping1, WANG Qi2, CHEN Xiang2. Continuous scanning laser Doppler vibrometry method for ODS measurements of flat plate structure with arbitrary rectangular holes[J]. Journal of Vibration and Shock, 2023, 42(19): 172-179

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