基于ANSYS平台的桥梁时域颤振阶跃函数算法

结合断面的颤振导数,采用阶跃函数对桥梁断面自激力进行模拟,并对模拟准确性进行了分析与校核;推导出时域颤振动力有限元分析中自激力的递推表达式。基于阶跃函数拟合气动力,利用APDL语言在ANSYS中实现了颤振时域分析;以一简支梁为例,介绍了在ANSYS中实现颤振时程分析的过程。数值算例计算结果和相关文献报道基本一致。研究表明:利用ANSYS的二次开发平台进行桥梁气动稳定性能的时域分析是可行的,该方法可提高桥梁颤振分析或颤抖振理论分析效率,降低自主开发大型软件过程中的算法错误或疏漏所带来的风险。

Indicial Functions Algorithm and Time Domain Flutter Analysis of Bridges Based on ANSYS Program

On the basis of sectional flutter derivatives,the indicial functions are firstly adopted in this literature to simulate the self-excited aerodynamic forces of bridge girder section,and,of which the simulation veracity is inspected.Then the recursive algorithm of bridge section self-excited aerodynamic forces,which is indispensable in the dynamic finite element analysis procedure,is deduced.Based on simulated self-excited aerodynamic forces,the time-domain flutter analysis is achieved in ANSYS in virtue of the embedded APDL language wherein.At last,a numerical example — a simple supported beam is selected to verify this method in time-domain using ANSYS software.Numerical example is in good accordance with what reported in the listed references.What presented in this paper shows it is feasible to conduct the time-domain investigation of aerodynamic stability of a bridge based on secondary development of the ANSYS program,which is capable of improving the efficiency of bridge flutter analysis or flutter-buffeting analysis,reducing the risk of algorithmic error or careless omissions involved in self-developing large software.