实测模态和结构模型同步修正的结构损伤识别方法

Structural damage identification by synchronally updating measured modes and finite element model

在基于灵敏度分析的有限元模型修正方法基础上,提出一种对实测模态和结构模型同步修正的结构损伤识别方法。即利用有损结构模态与测量噪声在时频域内的差异,以结构有限元模型为基准,对实测模态差进行小波去噪处理,再利用修正后的模态构造目标函数,进行有限元模型修正,经过迭代计算最终可识别结构的损伤。数值算例表明该方法可有效降低噪声的影响,提高损伤识别的精度。

A damage identification method by synchronally updating measured vibration modes and finite element model was developed based on the classic sensitivity-based model updating method.A wavelet de-noising treatment was proposed to reduce the noise in modal difference between measured model and analysis mode by the finite element model according to different time-frequency features between structural modal signal and noise.The de-noised modes were used to construct objective function and the optimal question was solved to update the finite element model,then the structural damage can be identified through iterative process.The numerical cases show that the proposed method has a good de-nosing performance and can identify structural damage more accurately.