大跨斜拉桥结构健康监测实验室模型试验平台

本文基于山东滨州黄河公路大桥,建立面向结构健康监测的实验室模型试验平台.基于相似理论,分析模型相关参数的相似关系,确定模型缩尺比、材料和截面尺寸,并对模型附加质量和斜拉索进行合理地简化.采用ANSYS建立物理模型的三维空间实体有限元数值分析模型,实体建模能较好的体现模型局部特征和模拟损伤.模型制作采用分段整体浇注,分段之间设计连接件连接,模拟斜拉桥施工顺序进行实验室组装,基于影响矩阵法对斜拉索进行张拉成桥.建立了包括传感器系统、静动力加载系统、数据采集系统和数据处理四大部分的完整试验体系,并对隔离出的桥塔和桥面板子结构进行了静动力试验,对全桥模型进行了动力测试.子结构和全桥模型的试验结果与有限元计算结果,以及原桥实测值都吻合较好,验证了斜拉桥模型的准确性和试验平台的有效性.试验系统的建立,为结构健康监测技术提供了一个试验研究平台.

On the Laboratorial Model and Experimental System for a Long-Span Cable-Stayed Bridge

Laboratorial model and experimental platform oriented to structural health monitoring (SHM) were established based on Binzhou Yellow River Highway Bridge in Shandong Province. The model scale ratio, materials and cross section dimentions were determined besed on parameter similarity from similarity theory, the added mass and cables of laboratorial model were simplified reasonably. Thus, a 3-dimentional finite element (FE) solid model was established, which can be analysed by ANSYS software. The physical model was fabricated in segments and assembled by special designed connectors. The whole model was assembled according to construction sequence of real bridge, and the influence matrix method was used for cable tension. Complete experiment system includes four parts: sensor system, static and dynamic loading system, data acquisition system and data processing system. A series of static and dynamic testing was implemented on substructures of bridge pylon and decks, as well as full bridge model. Experimental data, FE model analysis and real bridge measured value were compared. Results show that the accuracy of reduced-scale model and the validity of experimental system are verified.