基于参数灵敏度分析的连续刚构桥有限元模型修正  

FE Model Updating for Continuous Rigid Frame Bridge Based on Parameter Sensibility Analysis

作　　者：陈彦江[1] 程永欢 李勇[1,2] 李晰[1] 

机构地区：[1]北京工业大学工程抗震与结构诊治北京市重点实验室,北京市100124 [2]清华大学土木工程系,北京市100083

出　　处：《公路》2014年第7期144-149,共6页Highway

摘　　要：建立合理准确的有限元模型是大型桥梁健康监测系统中安全评估、预警及损伤识别的前提。以某三跨预应力混凝土连续刚构桥为例,根据设计资料利用ANSYS建立其初始空间三维有限元模型,利用桥上的健康监测系统采集得到的加速度时程数据,采用频域分解法和随机子空间法对实际结构的模态频率进行识别,依据识别结果,在参数灵敏度分析的基础上,根据最优化理论对该桥的有限元模型进行修正。研究结果表明,经修正后的有限元模型能真实准确地反映该桥梁结构的真实动力特性,可以作为健康监测系统中损伤识别、安全评估等研究工作的基准模型。The establishment of a reasonable and accurate finite element model is the precondition of safety assessment, early warning and damage identification in a large-scale bridge health monitoring system. In this paper, on the basis of design information, a three-dimension FE model of a long--span prestressed concrete continuous rigid frame bridge is built with ANSYS. With the employment of the acceleration time histories from health monitoring system of this bridge, the operational modal frequency is identified by FDD method and SSI method. According to the results of identification, the FE model has been updated using optimization theory after the parameter sensitivity analysis. Results show that the finite element model updated can truly reflect the actual dynamic characteristics of the bridge structure, which can be used as the benchmark model of damage identification and safety assessment in the health monitoring system.

关 键 词：连续刚构桥 有限元模型修正 参数敏感度 频域分解法 随机子空间法 约束优化 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]