【作者】 郑瑾；

【导师】 瞿伟廉；

【作者基本信息】 武汉理工大学 ， 结构工程， 2004， 硕士

【摘要】 过去，网架结构被认为是一种异常而非传统的结构，而现在却已被普遍地接受，成为一种既经济又美观、深受喜爱的结构。其具有空间刚度大、体系稳定、抗震性能好、受力合理等优点，但由于尺寸巨大，暴露在恶劣环境中，且受到多为随机性载荷作用，因此服役环境相当恶劣。结构智能健康监测，就是利用现场的、无损伤的一种监测方式，获得结构内部信息，分析包括结构反应在内的各种特征，以便了解结构因损伤或者退化而造成的改变。有效地对结构性能进行监测和诊断，在灾难到来之前及时发现结构的损伤，对可能出现的灾害进行预测，评估其安全性，保证大型工程结构的安全性与耐久性已经成为未来工程的必然要求，具有十分重要的科研价值。 本文以深圳市民中心为实际工程背景，深圳市民中心是深圳市新的政治文化中心和标志性建筑。其总建筑面积近21万平方米，大屋顶空间网架结构长486米，宽154米，是迄今为止世界上最大的网架结构。本文讨论了网架健康监测软件系统研究工作的一部分，其中包括：牛腿支座反力瞬时识别；牛腿焊缝及关键点应力分析；牛腿焊缝及关键点应力状态报警。所采取的研究方法为模糊数学中的模糊模式识别方法，并结合有限元分析方法，瞬时识别支撑钢牛腿的应力场。 网架结构的支撑钢牛腿的安全对于整个结构的安全性能起着关键性作用。本文首先介绍了模糊模式识别方法的相关理论基础，详细阐述了结构智能健康监测中模糊模式识别方法的基本原理及实现过程。同时，为验证模糊模式识别方法用于支撑钢牛腿瞬时应力场识别的有效性可行性，及工程现场采用的数据采集设备的准确性，本文中设计出模型牛腿，并进行了模型实验，并对实验结果进行了系统地研究及分析。同时进行了牛腿上关键点选择的参数分析的讨论。最后，针对深圳市市民中心现场屋顶网架结构的智能监测系统，介绍了支撑钢牛腿的智能化监测方法。其中包括，基于模糊模式识别理论的牛腿瞬时荷载的自动识别、牛腿关键点的选择、及关键点工作状态的评估与报警等等问题。 本文中，应用大型有限元计算软件ANSYS建立了钢牛腿的有限元模型，武汉理工大学硕士学位论文采用壳体单元进行分析。对其中重点监测的6个牛腿进行了在设计荷载下的静力计算分析，对各个牛腿的应力应变分布有一定程度的了解，确定了牛腿监测的关键区域及计算得到各需监测牛腿的应力场模式并存储下来。 钢牛腿瞬时应力场识别完成后，可立即判断其应力是否超界。如果超界，可立即报警，并且每个牛腿任意时刻的应力场状态都可以清晰的显示在计算机屏幕上，便于工作人员操作监测整个结构的安全性。更多还原

【Abstract】 In the past, space latticed truss structure was treated as a exceptional and non-traditional structure, but now is accepted as an economical and popular structure. In the one hand, there are many advantages in SLTS such as high space stiffness, moderate stability, good Earthquake resistance capacity, sound bearing capacity. In the other hand, due to magnitude dimension, subjected to random load ,and exposing in bad environment ,SLTS are affected easily by the natural disaster. Structure intelligent health monitor is a method using spot and non-damage equipment, getting structure internal information and analyzing all kinds characters of structure respo nse, then acquiring the structures change due to damage and degeneration. How to monitor and diagnose the capability of a structure and predict the damage before the disaster is become a research issue now.The intelligent inspect system for roof SLTS in Shenzhen citizen center is selected as a practice engineering background in this paper, the structure is a new political and cultural center and a symbolic architecture in ShenZhen which overall structural area is 2.1 million square meter, the roof is the largest space lattice in the world which is 486 meter long and 154 meter wide. In the paper, we discuss a part of the healthy monitor system, including instantaneous stress filed identification for bracket, stress anlysis of welding line and key point; alarm of key point stress condition. Fuzzy pattern recognition method and FEA method are adopted in the dissertation.The safety of steel bracket has close relationship with overall structure. In the paper, firstly, the fuzzy pattern recognition theory is introduced,structure intelligent healthy monitoring based on the fuzzy pattern recognition is analyzed in detail. In order to validate the feasibility of fuzzy pattern recognition applied to the stress fieldinstantaneous recognition and the accuracy of data-collection system, we design the bracket model and did a model experiment to prove the accuracy of data-collection system and the feasibility of fuzzy pattern recognition theory using data-collection system, then, we discuss the influencing factor in the selection of key point. Finally,the intelligent monitoring method is introduced including the instantaneous stress field identification of bracket and the selection of key points, the evaluation and alarm according to key points work state ,etc.In the paper, the FEA model is constructed using the large software ANSYS,the element adopt shell63 element. Through the static analysis of the important six brackets, we learned the distribution of stress and strain to some extent. Then we know the key area of the bracket, get many stress field modes and saved.After the instantaneous stress field identification of Steel bracket.we estimate the stress value. If the amount is larger than the limit, the monitor system can alarm at once.At the same time,any time stress condition of bracket can show on the computer screen that convenient the workers inspect the safety of structure.更多还原