摘要
在以往模态柔度损伤指标研究成果的基础上,提出模态柔度曲率改变率MFCI(aver)的结构损伤识别方法。该方法首先对损伤前后的模态柔度矩阵各列元素进行代数平均,将计算得到的平均值作为模态柔度向量{fu}和{fd}的元素,然后利用差分法求出模态柔度曲率,最后将损伤前后的模态柔度曲率差值按损伤前的模态柔度曲率值进行归一化,从而得到模态柔度曲率改变率指标。对简支梁和连续梁,采用MF,MFC,MFCI(aver),MFCI(max)4种结构损伤指标进行损伤识别效果比较的结果表明:模态柔度曲率改变率结构损伤识别方法在识别过程中,由于用模态柔度列向量代替模态柔度矩阵,避免了大型矩阵运算,明显提高了识别速度;对数据进行平均处理,明显改善了抗噪能力。
On the previous modal flexibility damage index based research achievements, a new damage detection method for bridge structure called modal flexibility curvature change ratio MFCI（aver） is introduced in this paper. In this method, each column elements of the modal flexibility matrix before and after the damage are first algebraically averaged. The average values from the calculation are used as the elements of the modal flexibility column vectors {f^u} and {f^d}. Then the modal flexibility curvature is obtained by difference method. The difference values of the modal flexibility curvature before and after the damage are normalized according to the modal flexibility curvature before the damage. The index of modal flexibility curvature change ratio can be further worked out. For simply supported beam and continuous beam, the damage detection effect is compared respectively by adopting MF, MFC, MFCI（aver） and MFCI（max） as the structure damage indices. Results indicate that during the structure damage detection process by modal flexibility curvature change ratio based detection method, owing to using modal flexibility column vector instead of modal flexibility matrix, large matrix computation are avoided and thus the detection speed is evidently improved. Due to the average treatment of data, anti-noise ability has been significantly improved.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2008年第5期51-57,共7页
China Railway Science
基金
铁道部科技研究开发计划项目(2007YF01)
关键词
桥梁损伤
损伤识别
模态柔度矩阵
模态柔度曲率改变率
损伤指标
Bridge damage
Damage detection
Modal flexibility matrix
Change ratio of modal flexibilitycurvature
Damage index
