基于激光旋转扫描的约束态薄壁圆柱壳模态振型测试新方法

摘要

The efficiency of the traditional method using experimental modal analysis to identify the mode shapes is much lower,so,a new experimental method was developed and a test system of laser rotating sanning was built to measure mode shapes of constrained thin cylindrical shell,which includes laser Doppler vibrometer,DC power supply,DC slowdown motors,mirrors,etc.The test procedure was proposed for the 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.The experimental method was demonstrated and verified by using a study case which shows it can get modal shapes of thin cylindrical shell efficiently and accurately.Moreover,it can greatly improve the spatial resolution at measuring points and can rapidly measure the vibration response of cylindrical shell structure.%针对传统采用实验模态分析理论辨识模态振型测试效率低的问题，提出基于单点激光旋转扫描的测试约束态圆柱壳模态振型新方法。在明确基本测试原理基础上组建激光旋转扫描测试圆柱壳模态振型实验系统，提出基于激光旋转扫描测试约束态模态振型试验流程，并对判定圆柱壳共振及由响应数据获得圆柱壳模态振型等关键技术进行详述。通过实例验证结果表明，该方法可快速准确获得薄壁圆柱壳的模态振型、极大提高空间测试分辨率、高效测试圆柱壳结构各点振动响应，具有一定工程应用价值。