基于物理参数辨识的框架结构的地震损伤诊断及其加固技术

发布时间：2018-02-27 01:31

本文关键词： 地震损伤物理参数辨识恢复力曲线修复与加固　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：结构的地震损伤可以通过结构物理参数的变化来估计，这样就可以借助于结构物理参数识别方法来识别结构的地震损伤。为了达到这个目的，首先需要识别出结构损伤后的物理参数，然后计算损伤前后的变化量，并建立这种变化与结构损伤状态参数间的关系，进而对结构地震损伤进行评定与修复加固。本文针对框架结构，采取复合反演算法、分频段加权最小二乘法两种方法对框架结构进行震前震后刚度识别，然后根据刚度的下降，确定结构的损伤量，进而完成对整体结构的加固与修复。归纳起来，本文的主要工作有： ①系统阐述了结构物理参数辨识方法、地震损伤识别模型以及震损结构加固与修复的现状与发展。 ②探讨了复合反演算法的基本理论以及计算流程，使用复合反演算法针对框架结构在输入条件未知的情况下进行物理参数辨识及地震动反演。通过算例证明了该方法的具有较强的抗噪性能，而且能够完成各中阻尼模型参数识别的问题。 ③探讨了小波函数的多尺度逼近方法的基本理论，利用以这种理论为基础的分频段加权最小二乘法完成框架结构的物理参数辨识问题。最后与最小二乘法、分频段最小二乘法进行对比，证明了这种方法的识别精度很高且具有较强的抗噪性能。 ④从材料层次、结构构件层次、结构整体层次三个方面探讨了地震损伤评估模型。采用了Ghobarah提出的直接以刚度比的形式定义的损伤指标。使用复合反演算法、分频段加权最小二乘法两种物理参数辨识的方法对某框架结构教学楼在地震前后的刚度进行了辨识，最后根据Ghobarah提出的刚度比模型确定了该框架结构的地震损伤指数。 ⑤根据上一章计算出的损伤指数，建立损伤后结构的恢复力曲线模型，根据修复后结构的初始刚度与屈服强度和原结构相等的原则，从而确定Pall摩擦型阻尼器所施加的紧固力矩。最后对修复后的结构进行地震响应计算，，并与完好结构对比，证明了加固后的结构不仅具有原有的抗震能力，而且还具有良好的减振的效果。
[Abstract]:The seismic damage of structures can be estimated by the variation of structural physical parameters, so that the seismic damage of structures can be identified by means of structural physical parameters identification. First of all, the physical parameters of the damaged structure should be identified, and then the changes before and after the damage should be calculated, and the relationship between the changes and the damage state parameters of the structure should be established. Then the seismic damage of the frame structure is evaluated and repaired and strengthened. In this paper, the composite inversion algorithm and the weighted least square method are used to identify the stiffness of the frame structure before and after the earthquake, and then according to the decrease of the stiffness, Determine the damage amount of the structure, and then complete the reinforcement and repair of the whole structure. To sum up, the main work of this paper is:. The main contents are as follows: 1. The methods of structural physical parameter identification, seismic damage identification model and the present situation and development of reinforcement and repair of damaged structures are systematically described. 2. The basic theory and calculation flow of compound inversion algorithm are discussed. The composite inversion algorithm is used to identify the physical parameters and the ground motion inversion of the frame structure under unknown input conditions. A numerical example shows that the method has strong anti-noise performance. Moreover, the problem of parameter identification of damping model can be completed. 3. The basic theory of multiscale approximation method of wavelet function is discussed. Based on this theory, the physical parameter identification problem of frame structure is completed by using the frequency division weighted least square method based on this theory. Finally, the least square method is used to identify the physical parameters of the frame structure. Compared with the least square method in frequency band, it is proved that this method has high recognition accuracy and strong anti-noise performance. 4. The seismic damage assessment model is discussed from three aspects: material level, structural member level and whole structure level. The damage index defined by Ghobarah in the form of stiffness ratio is adopted. The composite inversion algorithm is used. The stiffness of a frame structure teaching building before and after an earthquake is identified by two physical parameter identification methods of weighted least square method in frequency band. Finally, the seismic damage index of the frame structure is determined according to the stiffness ratio model proposed by Ghobarah. (5) according to the damage index calculated in the previous chapter, the restoring force curve model of the damaged structure is established. According to the principle that the initial stiffness of the repaired structure is equal to the yield strength and the original structure, Finally, the seismic response of the repaired structure is calculated, and compared with the intact structure, it is proved that the strengthened structure not only has the original aseismic capacity, And also has the good vibration absorption effect.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU317;TU375.4

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