考虑温度影响的曲线箱梁有限元模型修正

Finite Element Model Updating of Curved Box Girder Considering Temperature Effect

模型修正按修正对象的不同可分为矩阵型修正法和参数型修正法,参数型修正直接修正材料参数和几何参数,然而材料参数(如弹性模量)往往受环境因素,特别是温度的影响,如果不在修正过程中考虑温度对材料弹性模量的影响,往往会得到错误的结果。文中介绍了一种考虑温度影响、基于优化理论的曲线箱梁有限元模型修正方法。首先认为有机玻璃模型的弹性模量温度相关,建立了两者的关系模型。然后建立有机玻璃曲线箱梁的实验室模型和有限元分析模型,通过地震台振动测试获取了实验模态,通过ANSYS模态分析获取了理论模态。最后考虑了温度的影响、基于优化理论的零阶优化和一阶优化进行有限元模型修正,成功地消除了温度对模型修正的影响,得到了后续损伤识别的基准有限元模型。

There are two different model updating methods according to updating object,matrix form and parametric updating,the material and geometric parameters are updated directly in parametric updating,but the material parameters, such as elastic modulus are affected by environmental conditions,especially temperature,if the influence of temperature to material elastic modulus is not considered in the model updating,the actual results cannot be acquired. In the paper,a model updating method considering the influence of temperature,which is based on the optimization theory,is introduced. Firstly the elastic modulus of polymethylmethacrylate（ PMMA） is temperature-dependent,the relationmodel is setup. Secondly,the lab model and finite element model of the PMMA curved box girder are constructed,the experimental and analytical modes are acquired through vibration testing on a shake table and modal analysis based on ANSYS. In the end,the model updating considering the influence of temperature is carried out based zero-order optimization and first-order optimization,the baseline model for the later damage identification is obtained and the influence of temperature to model updating is eliminated successfully.