摘要
本文对任意空间杆系结构进行非线性动力稳定性分析。首先,采用非线性有限元法建立结构的动力微分方程;对动力微分方程中的微分项可通过拉普拉斯变换消去,动力方程中的非线性项则采用数值积分的方法进行拉氏变换,经过多次迭代得出位移在象空间的解,最后借助于数值拉普拉斯逆变换方法得出用最佳逼近而求得的以指数级数表示的位移的拟合函数。由拟合函数的敛散性即可判定结构的动力稳定性。
In this paper, the nonlinear dynamic stability of space structures was studied. Firstly, the dynamic differential equations were established by means of nonlinear finite element method, using Laplace transform, with the differential terms in equations euminated. Numerical integral method was used to carry out the transform in the nonlinear terms. After sufficient iteration steps, the displacements in image space were given. Finally, the fitting functions of the displacements described by geometric series were obtained via the weighted least square fitting and numerical Laplace inversion transform, the dynamic stability was justified by the convergence of the fitting functions.
出处
《上海力学》
CSCD
1999年第2期112-117,共6页
Chinese Quarterly Mechanics
基金
国家自然科学基金(编号:59578002)
关键词
动力稳定性
非线性
有限元
杆系
空间杆系
dynamic stability, nonlinear finite element, the least square fitting, numerical Laplace inversion method.
