【摘要】 针对航空发动机鼓筒等薄壁圆柱壳型结构,以薄壁圆柱壳为例,基于LabVIEW测试平台、利用非接触式电磁激振器搭建了模态参数测试实验台,并对实验台校准时的各个自由度偏差进行误差分析,给出灵敏度指数指导实验台校准。基于扫频信号包络线法辨识圆柱壳的固有频率,避免能量泄漏,提高辨识精度;基于共振响应辨识模态振型,利用激光旋转扫描测试,提高模态振型测试效率,并研究不同转速下的测试精度。将测试结果与LMS模态分析软件所测结果进行对比,结果表明,利用文中的测试方法得到的模态参数更为准确,具有一定的工程应用价值。更多还原

【Abstract】 Based on LabVIEW test platform, the modal parametric test platform for a thin cylindrical shell was built by using non-contact electromagnetic exciters. This test platform was calibrated with error analysis of each DOF’s deviation. Sensitivity indexes were given to guide calibration of the platform. Natural frequencies of the cylindrical shell were identified based on the sweep frequency signal envelope method to avoid energy leakage and improve recognition accuracy. Modal shapes of the shell were identified based on resonance responses. The laser rotating scanning test was used to improve modal shape test efficiency and the test accuracy was studied under different rotating speeds. The test results were compared with those using LMS modal analysis software. The results showed that modal parameters obtained with the proposed test method are more accurate; the proposed method has a certain engineering application value.更多还原