Extension of continuous scanning laser Doppler vibrometry measurement for complex structures with curved surfaces  

作　　者：Cuihong LIU Chaoping ZANG Biao ZHOU 

机构地区：[1]Aero-engine Thermal Environment and Structure Key Laboratory of Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

出　　处：《Chinese Journal of Aeronautics》2020年第12期3220-3227,共8页中国航空学报（英文版）

基　　金：the financial support for this work provided by the National Natural Science Foundation of China and National Safety Academic Foundation of China(No.U1730129);The Cultivation Foundation of National Defense Large Projects of China(No.NP2018450)。

摘　　要：The continuous Scanning Laser Doppler Vibrometry(SLDV)developed on the base of the galvanometer scanner system has made it possible to quickly obtain the full field vibration responses within a rectangular area of the structure.In this paper,an arbitrary continuous scanning path generating method for Continuous Scanning Laser Doppler Vibometry(CSLDV)is further put forward in order to allow the CSLDV suitable for testing structures featured by complex shapes not just for regular areas.In the first step,the relationship between position of laser spot and the driving voltages of galvanometer scanner system has been described by a mathematical modeling.Then,a novel arbitrary scanning path generating strategy based on CSLDV is presented by deforming a normalization rectangular scanning path to an arbitrary continuous scanning path.The mapping relation between the normalization rectangular scanning path and arbitrary continuous scanning path is established using the reference points.In the second step,a compressor blade with curved surface was taken as an example for modal test using the proposed method.At the same time,a validated experiment was performed in SLDV.The results show the mode shapes derived from the extended CSLDV are in agreement with those from SLDV and the Modal Assurance Criterion(MAC)between the two are all greater than 0.96.They also demonstrate the feasibility and effectiveness of the proposed method for CSLDV test and show strong potential on further practical engineering applications.

关 键 词：Arbitrary scanning path Continuous Scanning Laser Doppler Vibometry(CSLDV) Fitted polynomial Galvanometer scanner system Rectangular scanning path 

分 类 号：V231.92[航空宇航科学与技术—航空宇航推进理论与工程] TN249[电子电信—物理电子学]