【作者】 赵丹；

【导师】 袁朝庆；

【作者基本信息】 大庆石油学院 ， 防灾减灾工程及防护工程， 2007， 硕士

【摘要】 随着交通事业的蓬勃发展和大跨径桥梁建设步伐的日益加快,桥梁的安全性、适用性和耐久性日益受到人们的关注和重视。桥梁健康监测对于桥梁设计、建设、运营、维护及管理决策都有着重要的意义,其社会和经济效益显著,基于此桥梁结构的损伤识别研究就显得非常必要。本论文在损伤识别领域已取得的研究成果的基础上,针对传统数据处理方法存在的缺陷,探索了一种新的损伤识别方法。文中详细介绍了基本概念和希尔伯特-黄变换原理;利用希尔伯特谱识别了一模拟信号的突变时刻,旨在研究结构的损伤时刻,识别效果理想;建立了室内试验模型,采用Hilbert-Huang变换和传统时幅域分析中常用的五个无量纲参数(波形因数、峰值指标、裕度指标、峭度指标和脉冲指标)结合的方法,通过室内试验模拟,先后对单跨简支梁模型进行了损伤位置和损伤程度的识别,试验分析了在跨中、支座附近和1/4跨三个不同位置处加载,损伤类型为支座滑动和截面削弱,每种损伤又分别研究了外激励方式为正弦定频和线性扫频时的情况,取的了较好的效果。不足之处,HHT方法中存在的端点飞翼现象以及HHT的理论依据等问题,有待进一步的解决和研究。更多还原

【Abstract】 Bridge’s security, applicability and durability have come to people’s attention and concern along with the vigorous development of transportation as well as the pace of long-span bridge construction is speeding up day by day. The bridge health monitoring has vital significance in design,construction,operation,the maintenance and management decision,and its society and economic efficiency are remarkable. So bridge structure damage identification research is extremely essential.A new damage identification method is explored on foundation of the present research obtained in damage recognition domain, in view of the flaws in tradition data processing. Basic concepts and the principle Hilbert- Huang transform are detailed in the article; the Hilbert spectrum is used to distinguish a simulated signal sudden change time, the purpose is for studying the structure’s damage time and the effect is ideal. The experiment model is established. Experiment simulation is carried on The damage location and degree of a simply supported beam structure which is a single span are identified by cooperating HHT with five parameters(shape factor,crest factor,impulse factor,clearance factor,kurtosis value) in the traditional vibration signal without dimensional. Processes of the experiment are as follow: cross center and nearby the support and 1/4cross are loaded on; the damage types are skid for the support and sections weakened; the excitation include a linear scan and a sine signal whose frequency is determined. In conclusion,it got a better effect.The deficiencies are phenomenon of end wing as well as the theory basis of HHT, all these questions are waited for further solution and research.更多还原