摘要
为了将有限元模型修正方法引入到预应力混凝土主梁结构性能评估中,首先基于设计图纸,用有限元软件ANSYS建立后张法预应力混凝土T梁和箱梁的有限元模型。而后,综合运用动态加权系数和灵敏度分析的方法,以静载试验竖向挠度以及竖向前5阶自振频率为状态变量,构造目标函数。通过分析目标函数对设计参数的灵敏度,选取灵敏度高的设计参数对模型进行修正,调整了模型的物理参数,使模型计算值与试验结果在合理误差范围内。该方法克服了以往采用单目标函数修正有限元模型的不足,更易找到全局最优解。修正后的有限元模型按照静载试验加载工况进行加载,模拟分析了静载试验加载工况下2榀预应力混凝土梁有限元模型的应变、挠度计算结果,与现场静载试验测试结果相比较,其表明能够用于桥梁结构性能评估,可为类似工程提供借鉴。
In order to introduce the FE model updating method into evaluation of pre-stressed concrete girder,first,the finite element models of prestressed concrete T-girder and box girder are set up by ANSYS and posttensioning method based on the design drawings. Second,taking the vertical deflection in the static load test and the vertical natural frequencies of first 5 orders as the state variables,an objective function is constructed using dynamic weighting coefficients. After analysing the sensitivity of object function to the design variables,the model is modifies by the selected high sensitivity design variables. The physical parameters of the model are adjusted,the error between calculation value and test result of the model is converged into a reasonable error range. This method overcome the shortcomings of the usual method that using single objective function to modify FE model,and it is easier to get the globally optimal solution. After being modified,the values of strain and deflection of the 2-frame prestressed concrete girder FE model are analysed under the loading condition of static test. Compared with the data of in-situ static loading test,the modified model could be used in the assessment of bridge structure performance,and it can provide a reference for similar projects.
出处
《公路交通科技》
CAS
CSCD
北大核心
2015年第12期75-80,共6页
Journal of Highway and Transportation Research and Development
基金
山西省交通运输厅科技项目(2012-1-28)
关键词
桥梁工程
预应力混凝土梁
动静载试验
模型修正
灵敏度
bridge engineering
model updating
dynamic and static test
prestressed concrete girder
sensitivity
