时变环境下桥梁移动重车荷载与结构损伤协同识别方法研究

Under the conditions of time-varying environments and moving heavy vehicle loads, damages of bridge structures will be caused, accumulated and even a fatal bridge accident induced at last. It is necessary to immediately monitor the moving heavy vehicle loads, identify the structural damages and evaluate the safety of bridges. The objective of this study is to develop the dynamic system model of cracked bridges caused by the moving heavy vehicle loads under time-varying environmental conditions and to propose some new techniques on simultaneous identification of moving heavy vehicle loads and structural damages of bridges based on the synergetics, the dynamic deterioration behavior of cracked bridges and their differences in local micro- and meso-scale and in global macro-scale respectively. Considering the effects of environmental exogenous variables, the nonlinear dynamic equations of environment-vehicle-bridge clustering is formed. The stable and unstable prototype patterns are distinguished, the endogenous variables determined and the order parameters of the clustering also evolved. Some new space, time and function structures are created and the self-organizing evolution mechanism of structural damages of bridges is finally explored. Combining the synergetics theory and the most recent achievements on structural damage detection, the synergetic effects and the space linked problems of order parameters of structural damage in global macro-scale and in local micro- and meso-scale respectively will be well investigated. The accuracy and efficiency of simultaneous identification of moving heavy vehicle loads and structural damages of bridges are improved and some technical supports are provided for structural health monitoring of bridges as well.

桥梁结构在时变环境因素与超载移动重车荷载作用下发生损伤并逐步积累扩大，甚至诱发桥梁事故，实时监控桥梁移动重车荷载、及时识别桥梁结构动力损伤并评估其安全性的研究工作迫在眉睫。本课题基于协同学原理和桥梁结构动力劣化行为及其位于整体结构宏观尺度与局部微-细观尺度的差别，建立含裂纹桥梁在时变环境因素和移动重车作用下的动力系统模型，提出时变环境下桥梁移动重车荷载与结构损伤协同识别新方法。在环境外生变量作用下构建环境-车-桥集群系统的非线性动力学方程，创建集群协同识别原型模式并区分稳定/不稳定原型模式；确立集群属性内生变量，演化序参量，形成新的空间、时间和功能结构并探寻结构发生损伤质变的自组织演变机理。重点融合协同学理论和结构动力损伤识别最新成果，考虑结构损伤局部微-细观与整体宏观尺度序参量空间关联问题与协同效应，以期提高桥梁移动重车与结构损伤协同识别精度和效率，为桥梁结构健康监测提供技术支持。

桥梁结构在时变环境因素与超载移动重车荷载作用下发生损伤并逐步积累扩大，甚至诱发桥梁事故，实时监控桥梁移动重车荷载、及时识别桥梁结构动力损伤并评估其安全性的研究工作迫在眉睫。本项目采用理论、计算与实验有机结合的方法，基于协同学原理和结构动力劣化行为研究了时变环境下的桥梁移动重车荷载与结构损伤协同识别问题。考虑结构劣化位于整体结构宏观尺度与局部微-细观尺度的差别，建立了时变环境下损伤结构时变动力系统模型并发展了结构多尺度动力建模与优化方法，研究了传感器优化布置策略，提出了多种桥梁移动荷载识别、结构损伤识别以及桥梁移动荷载与结构损伤协同识别新方法。其中，重点融合了协同学原理和结构损伤识别最新成果，在环境因素和运行条件等外生变量作用下构建了车-桥系统的非线性动力学方程，确立了结构损伤集群属性内生变量与演化序参量并探寻了桥梁结构发生损伤质变的自组织演变机理，提高了桥梁移动荷载与结构损伤协同识别的精度和效率，为桥梁结构健康监测提供了技术支持与借鉴，具有重要的科学意义和工程应用价值。