混凝土框架模型结构参数的识别

Parameter identification of a model concrete frame structure

框架结构是常见的建筑结构形式,也是结构损伤诊断的主要研究对象之一。本文以钢筋混凝土框架结构模型的振动测试数据为基础,采用灵敏度分析方法,对结构的物理参数进行识别。有限元分析中,考虑框架结构的节点转动,采用静凝聚方法得到结构刚度矩阵。参数识别结果表明,对于不同的固有频率和振型的测试信息组合所识别的物理参数有所不同。根据已知的概率分布,利用MonteCarlo方法,将模态参数的不确定性传递给物理参数,得到了物理参数的不确定性。

Frame structure is an ordinary type of building structures and also a primary research objective in structural damage diagnoses. This paper presents an identification method of physical parameters in a model reinforced concrete frame structure based on sensitivity analysis and measured natural frequencies and modal shape. In finite element analysis the rotation of joints in the frame structure is considered. Then the rotation variables are eliminated by the static condensation method and the total stiffness matrix is obtained. From parameter identification results it is shown that the modal characteristics of frame structures can be accurately computed by the analytical model used in this paper. The physical parameters identified may change with the variable combination of measured information. Based on the assumed probability distribution, using Monte Carlo simulation method, the randomness of modal parameters are transferred to the physical parameters. Then the randomness of physical parameters can be calculated.