移动荷载作用下基于HHT和相空间重构法的桥梁损伤识别

发布时间：2018-06-20 00:57

本文选题：结构损伤检测 + 相空间重构　；参考：《暨南大学》2014年硕士论文

【摘要】：随着我国经济的快速发展，各类现代化的大型、复杂桥梁结构发展迅速。然而，复杂的服役环境使结构的运行安全日益遭受潜在的威胁，大型复杂结构一旦发生事故，所带来的损失和影响都是惊人的。因此对结构的健康状况进行适时的评估变得尤为重要。传统的基于模态的损伤检测方法存在着许多缺点和不足，如需要较密集的测点，，较低的识别精度等。本文就目前桥梁结构健康监测和损伤检测所面临的问题和挑战进行讨论和研究，对Hilbert-Huang变换（HHT）和相空间重构方法单测点损伤识别进行深入的研究。通过结合理论推导和数值模拟分析，HHT和相空间重构方法在桥梁损伤识别中的优越性得到证实。文中主要以下从三方面着手讨论： 1.首先介绍了桥梁结构损伤检测的重要意义。通过介绍该领域的发展现状，概括性叙述了传统方法在应用中遇到的问题及不足之处。针对这些不足之处，本文引入移动荷载作用下HHT和相空间重构的损伤检测方法，并详细叙述了这两种方法的发展状况。 2.理论部分：介绍了HHT方法的计算过程，并将该过程应用于欧拉-贝努利简支梁模型的振动解析表达式中，以讨论该方法损伤识别原理。同时也介绍了相空间重构方法的参数（延迟时间和嵌入维数）的选取，以及相空间重构方法的损伤识别原理。研究表明，这两种方法通过单测点能够识别出梁结构的损伤位置。 3.模拟和实验部分：首先将简支梁模型用于验证方法的可行性，并给出数值模拟中各种参数（荷载速度，损伤位置，程度等）对识别结果的影响，以初步研究这两种方法在损伤识别中的应用。进而通过海珠桥模型进行荷载参数和不同工况的研究，以进一步研究文中方法在复杂结构损伤检测中的适用性。结果表明，文中方法在这两种模型中都能很好的定位损伤，而且对损伤都具有较高的敏感性；两种方法的定性比较看出，相空间重构方法能更高效、更稳定的识别损伤状态。在海珠桥模型的初步实验研究表明，两种方法都能通过指标的最大值识别出损伤，同时对损伤的灵敏度都有所下降；荷载大小、速度等因素对识别结果的影响规律和模拟结果一致。
[Abstract]:With the rapid development of China's economy, various modern large-scale, complex bridge structures are developing rapidly. However, the complex service environment makes the operation safety of the structure suffer the potential threat day by day, once the large-scale complex structure has the accident, the loss and the influence are all astonishing. Therefore, timely assessment of the health status of the structure becomes particularly important. The traditional modal based damage detection method has many shortcomings, such as the need for more dense measuring points, low recognition accuracy and so on. In this paper, the problems and challenges of bridge structure health monitoring and damage detection are discussed and studied. The Hilbert-Huang transform (HHT) and phase space reconstruction method for single point damage identification are deeply studied. The advantages of HHT and phase space reconstruction in bridge damage identification have been proved by theoretical derivation and numerical simulation. The main contents are as follows: 1. At first, the importance of damage detection of bridge structure is introduced. By introducing the development of this field, the problems and shortcomings of traditional methods in application are described. In view of these shortcomings, the damage detection method of HHT and phase space reconstruction under moving load is introduced in this paper, and the development of these two methods is described in detail. 2. Theoretical part: the calculation process of HHT method is introduced and applied to the vibration analytical expression of Euler-Bernoulli simply supported beam model to discuss the damage identification principle of this method. At the same time, the selection of the parameters (delay time and embedding dimension) of the phase space reconstruction method and the damage identification principle of the phase space reconstruction method are also introduced. The results show that the two methods can identify the damage position of the beam structure by a single measuring point. 3. 3. Simulation and experiment: firstly, the simply supported beam model is used to verify the feasibility of the method, and the influence of various parameters (load velocity, damage location, degree, etc.) on the identification results in numerical simulation is given. The application of these two methods in damage identification is studied preliminarily. Then the load parameters and different working conditions of Haizhu Bridge model are studied to further study the applicability of this method in the damage detection of complex structures. The results show that the proposed method can locate the damage well in both models and has a high sensitivity to the damage, and the qualitative comparison of the two methods shows that the phase space reconstruction method can identify the damage state more efficiently and stably. The preliminary experimental study on the Haizhu Bridge model shows that both methods can identify the damage by the maximum value of the index, and the sensitivity of the damage is decreased. The effect of velocity and other factors on the recognition results is consistent with the simulation results.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U446

【参考文献】