基于第2代小波的有限元模型更新方法  

Finite Element Model Updating and Damage Identification Based on the Second Generation Wavelet Analysis

作　　者：张欣[1] 刘洋[1] 高丹盈[1] 

机构地区：[1]郑州大学土木工程学院,郑州450001

出　　处：《振动．测试与诊断》2015年第4期660-665,796,共6页Journal of Vibration,Measurement & Diagnosis

基　　金：河南省科技攻关资助项目(112102310453)

摘　　要：提出了有限元模型更新刚度曲线的低分辨率表示方法。基于有限的实验模态信息,通过遗传算法得到了更新刚度曲线在低分辨率表示时的尺度函数系数和小波系数。利用多分辨率分析方法实现了复杂精细有限元模型的几何降维,获得了在有限模态参数范围内与精细模型相似的简单有限元模型,并在此简单模型基础上实现了最终的模型更新与损伤识别。证明了从多分辨率分析的角度出发,利用第2代小波变换的方法能够减少待更新的参数数量,降低模型更新过程的奇异性。以变截面箱梁为例,验证了提出方法对裂缝深度变化和局部裂缝数量变化的鲁棒性。本研究方法也适用于多组裂缝群的辨识。A novel method is proposed for finite element model updating and structural damage identification.The second generation wavelet is used as a platform for the multi-resolution representation of the updating information.This method reduces the uncertainty of the model updating process.At the lower level of resolution,the updating curve of stiffness is represented by a limited number of scaling and wavelet coefficients,which are realized with the generic algorithm(GA).The complex finite element model is simplified by matching a number of modal parameters for easy manipulation in the updating process.Then,damage identification is carried out based on the simplified model.An example of a box girder with variable cross-sections is given for varying sectional properties to show the effectiveness of the proposed method.The results indicate that the proposed method is stable against variations in crack depth and changes in the number of concentrated cracks.The method is also suitable for the identification of multiple groups of cracks.

关 键 词：模型更新 损伤识别 多分辨率分析 小波分析 

分 类 号：TU311.3[建筑科学—结构工程] U441[建筑科学—桥梁与隧道工程]