基于应用程序交互访问技术的桥梁有限元模型修正研究

RESEARCH ON UPDATING FINITE ELEMENT MODEL FOR BRIDGE BASED ON APPLICATION PROGRAMMING INTERFACE TECHNIQUE

传统的有限元模型修正方法对于具有复杂多自由体系的大型桥梁结构显得束手无策,其中一个重要的原因是大型桥梁结构体系很难用有限元编程精确地表达,难以建立完整的或者缩聚的质量矩阵和刚度矩阵。该文开发了基于应用程序交互访问的有限元模型修正模式,首先在Strand7软件中建立初始的有限元模型,然后利用MATLAB建立迭代程序并调用Strand7软件,通过读写Strand7中的物理参数来更新模型,实现了大型桥梁结构有限元模型修正。该文对一座实桥进行多参考点脉冲锤击法模态试验和静载试验,基于获得的静动力试验数据和Strand7有限元模型分析结果,引入损伤函数的概念识别得到了该桥各梁的分段刚度,成功地实现了单元层次的参数识别。

A traditional model-updating method can hardly deal with a large complex bridge structural system with multi-degrees of freedom. An important reason is that a structural system is difficult to be accurately represented by the finite element （FE） model coding, and that especially the complete or reduced mass matrix and stiffness matrix are difficult to be built. In this paper, a FE model-updating method based on an application programming interface （API） was developed. An initial FE model was built in Strand7 software, and the physical parameters in Strand7 was rewritten by using MATLAB interactive coding. Thusly, the model can be updated iteratively by MATLAB procedure, and the model updating of large bridge structures was realized. An in-situ bridge was tested by using a multi-reference hammer impact modal test and a truck-load test. The concept of a damage function was introduced to model identification. By comparing between the test data and finite element analysis results, the stiffness of each girder has been identified. Finally, the parameter identification in element level was successfully realized.