摘要
面向基于动态应变监测数据的结构损伤诊断问题,提出了一种仅利用一阶应变模态振型及其灵敏度分析的损伤定量诊断策略。该策略利用事先规定应变测量单元的变形体结构或构件应变响应数据,通过NExT-ERA方法提取进而筛选识别精度较高的某一阶应变模态振型向量,由该阶特征向量求导得到灵敏度矩阵的同时,提出对其进行参考点归一化以避免质量归一化过程,最后通过求解损伤方程组得到单元刚度参量的改变。分别以下承式钢桁梁桥主桁架和装配式T形简支梁桥主梁简化模型为例,验证了该策略的有效性,分析了识别精度、噪声干扰和损伤程度对诊断效果的影响。该研究可为基于实时监测的结构在线诊断提供一定的理论和技术支持。
Aiming at the structural damage detection based on the dynamic strain data, a type of quantitative damage detection diagnosis strategy is proposed by using single-order strain mode shape and its sensitivity analysis. The strategy is implemented as follows. First, the strain data on the pre-defined strain measurement elements of the deformable-body structure or component are utilized to identify one single-order strain mode shape vector based on NExT-ERA method. Then, the sensitivity matrix is derived from the eigenvector derivation and the reference-point normalization is presented for avoiding the mass normalization. On these bases, the changes of the element stiffness parameters can be updated through the damage equations. Two simplified models, including the main truss of a steel truss girder bridge and the main beam of a fabricated Tshaped simple supported girder bridge, have been taken as the illustration to substantiate the proposed strategy. The influences of the identified precision of the strain mode shape, the noises and the extents of damages are investigated, respectively. This study provides a way to a certain extent to help the damage detection based on the structural health monitoring in a real time.
出处
《振动工程学报》
EI
CSCD
北大核心
2016年第6期976-984,共9页
Journal of Vibration Engineering
基金
国家高技术研究发展计划(863计划)(2014AA110401)
关键词
应变模态
损伤定量
应变测量单元
特征向量求导
参考点归一化
strain mode shape
quantitative damage detection
strain measurement element
eigenvector derivatiom referencepoint normalization
