基于响应面的预应力混凝土桥动力有限元模型研究

建立了基于正交实验的响应面模型和精细有限元模型，并将其用于中华大桥的有限元模型修正，通过实测动力数据对修正后的有限元模型计算结果进行了验证。基于修正后的有限元模型，分析了预应力对预应力钢筋混凝土桥梁模态信息（频率和振型）的影响，以及单元类型对桥梁模态频率的影响。结果表明，修正后的有限元模型能够比较准确地反映桥梁实际结构的动力特性，基于响应面模型和遗传算法的修正方法可有效地用于大桥的健康监测和状态评估；预应力对预应力钢筋混凝土桥梁模态信息的影响较小，建模时可不予精确考虑；对于由多根预应力混凝土梁组成的桥梁体系，采用实体单元分析较好。

Research on Dynamic Finite Element Model of Prestressed Concrete Bridge Based on Response-surface

The response surface model and the detailed finite element model were established, they were used for updating the finite element model of Zhonghua bridge, and the results from the updating finite element model were verified by measured dynamic data of the bridge. And based on the updated finite element model, the influence of presti：ess on modal information （fre- quency and vibration mode） for prestressed reinforced concrete bridge and the element type on the bridge modal frequency were analyzed. The results show that the updated finite element model can accurately represent the dynamic characteristics of the bridge structure, the updating method based on response surface model and the genetic algorithm can be used efficiently in health moni- toring and condition evaluation. Besides, prestress rarely affects the modal information of the prestressed reinforced concrete bridge, and solid element is a better choice for the bridge system composed of multiple prestressed concrete beams.