间隙非线性结构气弹响应分析程序的DMAP开发

Development of Aeroelastic Response Solution Sequence with DMAP Language for Freeplay Nonlinear Structure

对大型工程结构,目前MSC/NASTRAN提供了线性颤振、线性气弹的计算功能,但无法进行非线性结构的气弹响应分析。本文采用Roger有理函数拟合法,从简谐运动情况下NASTRAN求得的若干折减频率下的非定常气动力系数矩阵,导出任意运动情况下的非定常气动力近似表达式,并将该气动模型引入到非线性运动方程中,利用DM AP语言在NASTRAN非线性瞬态响应分析程序中加入相关气动力模块,实现了大型有限元机翼结构的非线性气弹响应分析。文中给出了算例,结果验证了该法分析间隙非线性结构气弹响应的有效性。

For engineering structures, MSC/NASTRAN supplies the functions for analyzing linear flutter and linear aeroelastic response, however, the aeroelastic response of the nonlinear structures can＇t be studied. The Roger rational function fitting method is adopted to deduce the approximative expressions of the unstationary aerodynamics in arbitrary motion, based on the coefficient matrices of unstationary aerodynamics in simple harmonic motion computed with NASTRAN on few reduced frequencies, and then the expressions are introduced into the nonlinear dynamic equations. According to this, the corresponding aerodynamic modules are inserted into the NASTRAN nonlinear transient response solution sequence with DMAP language for analyzing the nonlinear aeroelastic response of the huge finite element wing model. The example proves the method is effective to analyze the aeroelastic response of freeplay nonlinear structure.