A experimental method of laser rotating canning to measure mode shape of constrained thin cylindrical shell
LI Hui1,SUN Wei1,XU Zhuo1,HAN Qing-kai2
1.School of Mechanical Engineering & Automation, Northeastern University, Shenyang 110819, China; 2. School of Mechanical and Engineering, Dalian University of Technology, Dalian 116024, China
Abstract:Getting mode shapes of constrained cylindrical shell have important implications for the dynamic design as well as vibration suppression of its structural components. The efficiency of the traditional method using experimental modal analysis theory to identify the mode shapes is much lower, so this paper developed a new experimental method and build a test system of laser rotating canning to measure mode shapes of constrained thin cylindrical shell, which including laser Doppler vibrometer, DC power supply, DC slowdown motors, mirrors, etc. Then, the test procedure was proposed for this test system. And how to determine the resonance of the cylindrical shell and how to obtain mode shapes from response data as well as other key technologies were described in detail. At last, this experimental method has been demonstrated using a study case which shows it can get modal shapes of thin cylindrical shell efficiently and accurately. Moreover, it can greatly improve spatial resolution of measuring points. Thus, it can be used to rapidly measure vibration response of the cylindrical shell structure. This study can provide important references to applications of vibration test of cylindrical shell in engineering field.