基于模态参数及小波变换的旋转梁结构损伤识别

本文采用旋转悬臂梁模型模拟旋翼直升机桨叶结构，并对其开展损伤识别问题研究.首先，基于有限元方法，采用Hamilton变分原理，建立旋转结构的动力学模型，通过对比理论和实验的结果验证模型的正确性.其次，利用不同模态参数(位移模态、应变模态)对旋转悬臂梁结构进行损伤识别研究.最后，针对位移模态，基于小波变换的奇异性分析特性，研究通过小波系数辅助损伤识别的方法.计算结果表明，对于旋转结构，应变模态的损伤识别效果较好，而位移模态若结合小波变换的奇异性分析，同样可以实现较为准确的损伤识别效果.

Damage identification of rotating beams based on mode parameters and wavelet transform

In this paper, a rotating cantilever beam is used to simulate the rotor helicopter blade structure, and the damage identification problem is studied. Firstly, based on finite element method and Hamilton variational principle, a dynamic model of rotating structure is established. The model is verified by comparing theoretical and experimental results. Secondly, the damage identification of the rotating cantilever beam is studied by choosing different mode parameters (displacement mode and strain mode). Thirdly, for the displacement mode, based on singularity analysis characteristics of wavelet transform, the method of damage identification assisted by wavelet coefficients is studied. The results show that the damage identification effect of strain mode is better for rotating structure, and the displacement mode can achieve a more accurate damage identification if it can be combined with the singularity analysis of wavelet transform.