结构安全的多级评定方法研究

发布时间：2018-02-16 23:15

本文关键词： 应力识别模式库更新安全评定 MATLAB GUI 钢结构　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：结构健康监测是土木工程领域新兴技术，近三十年来在国内外得到迅速发展。应力监测是结构健康监测的重要内容，可提供结构关键部位的实时测量信息，为结构的安全评定提供了基础数据，可直接对关键杆件进行评定。而关键测点的安全信息不足以反映整体结构的安全状况。为进一步研究整体结构的安全状况，需要对整体结构的应力进行估算，应用应力模式识别方法能够获取未知测点的应力。由于实际结构与有限元模型存在误差，结构使用期内荷载较为复杂，相应测点并不能代表结构的最不利部位。识别未知测点应力时，影响识别效果的主要因素在于标准模式库代表荷载工况与实际荷载工况的差别。提出结构安全三级评定方法，分别为基于规范的简单评定方法，基于整体结构模型与测点局部模型有限元分析的高级评定方法和基于模式库更新的智能评定方法。三级安全评定方法。根据实际工程设定多级安全阈值，用监测数值与安全阈值对比，，确定测点的安全等级，给出结构安全的简单评定；使用有限元软件分析结构，为给出更符合结构实际工作状态的评定限值，明确测点的安全阈值，采用整体模型分析和测点实体模型分析结合的方式，实现对结构安全的高级评定；应用模式识别的方法识别未布置传感器部位的应力，与有限元分析结果进行对比，确定测点安全状态，给出结构安全的智能评定。基于模式库更新的应力识别方法。确定已知测点和待识别测点，通过有限元分析建立包含已知测点和待识别测点应力信息的标准模式库；用包含已知测点应力信息的实测模式与标准模式库匹配，选择相近的工况，获取相应的待识别测点应力信息，加入标准模式库；用实测数据与更新后的标准模式库匹配，选择相近的工况，获取识别值。三级安全评定软件包设计。以三级安全评定方法为基础，应用MATLAB GUI平台进行软件包设计，根据程序功能，设计程序界面，通过编写程序代码控制程序响应，应用于顶模钢结构系统的安全评定。
[Abstract]:Structural health monitoring is a new technology in the field of civil engineering, which has been developed rapidly in recent 30 years. Stress monitoring is an important content of structural health monitoring, which can provide real-time measurement information of key parts of structure. It provides the basic data for the safety assessment of the structure and can directly evaluate the key members. However, the safety information of the key measuring points is not enough to reflect the safety situation of the whole structure. It is necessary to estimate the stress of the whole structure, and the stress of unknown measuring points can be obtained by using the stress pattern recognition method. Because of the error between the actual structure and the finite element model, the load in the life of the structure is more complicated. When the stress of unknown measuring point is identified, the main factor that affects the identification effect lies in the difference between the standard mode library and the actual load condition. A three-level assessment method for structural safety is proposed, which can not represent the most disadvantageous part of the structure. They are simple evaluation methods based on specifications, advanced evaluation methods based on finite element analysis of global structural model and local model of measuring points, and intelligent evaluation methods based on updating of pattern library. According to the practical engineering, the multi-level safety threshold is set up, the safety grade of the measuring point is determined by comparing the monitoring value with the safety threshold, and the simple assessment of the structure safety is given, and the structure is analyzed by the finite element software. In order to give the assessment limit which is more in line with the actual working state of the structure and to define the safety threshold of the measuring point, the advanced assessment of the structure safety is realized by the combination of the integral model analysis and the solid model analysis of the measuring point. The method of pattern recognition is used to identify the stress of the unarranged sensor, and compared with the result of finite element analysis, the safety state of the measuring point is determined, and the intelligent assessment of structural safety is given. The stress recognition method based on the updating of the pattern library is used to determine the known measuring points and the measuring points to be identified, and the standard pattern library containing the stress information of the known measuring points and the measuring points to be identified is established by finite element analysis. By matching the measured model with the standard mode library, which contains the known stress information of the measuring point, selecting the similar working conditions, obtaining the corresponding stress information of the measuring point to be identified, adding the standard pattern library, matching the measured data with the updated standard pattern library, Select similar working conditions and obtain recognition values. Based on the method of three-level safety assessment, the software package is designed by using MATLAB GUI platform. According to the program function, the program interface is designed, and the program response is controlled by programming code. It is applied to safety assessment of top die steel structure system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU317

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