论文部分内容阅读
工程结构损伤的识别与定位研究以往主要针对梁、框架等结构形式.损伤表现为信号局部特征的改变,而小波分析在时域和频域上都具有表征信号局部特征的能力.为提高结构损伤识别方法的准确性和适用性,将小波分析引入到网壳结构损伤识别中.根据小波奇异性检测理论,提出将模态应变能和小波变换相结合的方法对网壳结构进行定位,即以结构损伤前后单元模态应变能差作为结构损伤指标,对其分别进行bior6.8连续和离散小波变换,利用小波系数极大值点判断网壳结构有无损伤和损伤位置.以跨度40m的Kiewitt网壳结构为例进行数值模拟,结果表明:基于模态应变能和小波变换相结合的方法,在测得一阶模态下,不但对单一损伤而且对多损伤均能有效地识别出结构的损伤位置,证明该方法对此类结构损伤定位具有有效性和实用性.
In the past, the research on the identification and localization of engineering structural damage mainly focused on the structural forms of beams and frames, etc. The damage manifests itself as the change of the local characteristics of the signal, while the wavelet analysis has the ability of characterizing the local features of the signal in the time and frequency domains. The accuracy and applicability of the method are identified, and the wavelet analysis is introduced into the damage detection of the reticulated shell structure.According to the wavelet singularity detection theory, the method of combining the modal strain energy with the wavelet transform is proposed to locate the reticulated shell structure, that is, The modal energy difference of the unit before and after structural damage is taken as the structural damage index, and their bior6.8 continuous and discrete wavelet transforms are respectively used to determine the location of damage and damage of the reticulated shell based on the maximum value of the wavelet coefficient.With the Kiewitt The results show that based on the combination of modal strain energy and wavelet transform, in the first-order mode, the structure can be identified not only for single damage but also for multiple damage It is proved that this method is effective and practical for the damage localization of such structures.