基于拟合模态法的大范围运动柔性曲线梁动力学建模方法研究

大范围运动柔性曲线梁的动力学建模主要采用有限元法，这是由于很难得到曲线梁模态的解析模态表达式，求解的复杂程度随着单元的增加而增加。本文提出一种拟合模态法进行动力学建模，把大型有限元分析软件计算得出的模态拟合成为多项式的形式，得到曲线梁模态的近似解析表达式，从而大大简化了建模与计算的过程。以某型号卫星抛物面天线为例，验证了方法的可行性与准确型。

Dynamic model of a moving flexible camber beam by the method of fitted modal

Because of the difficulty in finding the analytic modal,the dynamics analysis of a moving flexible camber beam is often by means of Finite Element Method (FEM).The processes of FEM become very complex with the increasing of elements.A new method called Fitted Modal Method (FMM) was described in this paper as a alternative.The discrete modal solution of a camber beam was calculated by FEM software such as ANSYS and the approximate analytic modal expressions were obtained by fitting the discrete modal into the form of polynomial expression.This made the modeling and solving processes simple and convenient.The dynamic analysis of a paraboloid antenna was used as an illustrative example to verify the accuracy of FMM.