基于附加虚拟物理参数的板式轨道结构损伤识别方法与试验研究

The railway track structure has complicated composing and various forms of damage. Its damage identification using structural dynamic response often results in the insensitivity for local damage and demand for large amount of measurement points. In this project, the damage identification method using additional virtual physical parameters is proposed for the interface damage of CA mortar in slab track structure. Firstly, the construction equation of virtual physical parameters is deduced based on Virtual Distortion Method. The structural local dynamic characteristics are changed via adding virtual physical parameters such as virtual mass, damping or stiffness on the actual structure, and then the modal information with high sensitivity to the local damage can be constructed. Secondly, a large number of modal data can be obtained by adding moving virtual physical parameters and thus the demand for sensors is reduced. Then, the influences of measurement errors and model uncertainties are considered using Bayesian theory, and a damage identification method is developed based on additional moving virtual physical parameters to ensure the accuracy and reliability of virtual physical parameter construction as well as the damage identification. Moreover, in order to improve the test efficiency, a movable vibration device which integrates with excitation and sensor system is designed to meet the theoretical and experimental requirements. Finally, the numerical simulations and experimental tests are performed to verify the validity and practicability of the proposed method. The study of this project is suitable for fast detection of interface damages in slab track structures due to its simple implementation with fast tests and less sensors. In addition, it provides a new idea of damage identification for other engineering structures.

铁路轨道结构组成复杂且损伤形式多样，利用结构动态响应识别其损伤常常存在响应对局部损伤不敏感和测点要求较多的问题。针对板式轨道CA砂浆的层间损伤，提出附加虚拟物理参数的损伤识别方法。首先基于虚拟变形法推导虚拟物理参数构造方程，通过在实际结构上附加虚拟质量、阻尼或刚度物理参数改变结构局部动力特性，构造对结构损伤具有较高灵敏度的模态信息；然后通过移动布置虚拟物理参数构造出大量模态数据，所需传感器数目少；接着基于贝叶斯理论考虑测量误差和模型不确定性等影响，发展基于移动附加虚拟物理参数的损伤识别方法，保证虚拟物理参数构造和损伤识别的准确性和可靠性；继而设计能满足理论方法与试验要求且集激励和传感于一体的可移动激振装置，提高试验效率；最后通过数值仿真和试验验证方法的有效性和实用性。本项目方法需要传感器少、测试简单快速，适合板式轨道层间损伤的快速检测，同时为其他工程结构的损伤识别提供一种新的思路。

铁路轨道结构组成复杂且损伤形式多样，利用结构动力响应识别其损伤常常存在响应对局部损伤不敏感和测点要求较多的问题。.本项目针对板式轨道水泥沥青（CA）砂浆的层间损伤，提出了附加虚拟物理参数的损伤识别方法。在结构上附加物理参数是提高结构动力响应或模态对损伤灵敏度的有效方法，本项目首先基于虚拟变形法推导了虚拟物理参数构造方程，通过在实际结构上附加虚拟质量、阻尼或刚度物理参数改变结构局部动力特性，构造对结构损伤具有较高灵敏度的模态信息；同时，鉴于基于模态的损伤识别方法具有优化效率高且鲁棒性强的优点，提出了利用构造响应识别结构模态再进行损伤识别的方法。然后，通过移动布置虚拟物理参数构造出大量模态数据，所需传感器数目少。接着，为提高损伤识别的准确性和可靠性，基于贝叶斯理论考虑测量误差和模型不确定性等影响，发展了基于移动附加虚拟物理参数的损伤识别方法，保证虚拟物理参数构造和损伤识别的准确性和可靠性；继而设计了能满足理论方法与试验要求且集激励和传感于一体的可移动激振装置，提高了虚拟物理参数的构造精度和试验效率；最后通过数值仿真和试验验证了方法的有效性和实用性。.本项目研究验证了基于附加虚拟物理参数和贝叶斯理论的损伤识别方法的有效性，以及可移动激振装置对板式轨道层间损伤快速检测的适用性，同时为其他工程结构的损伤识别提供一种新的思路。