二自由度结构受迫非线性振动响应的数值计算

本文研究了由飞机尾部简化而成的二自由度结构受迫非线性振动,由于对复杂的运动方程不作进一步简化,方程中含有强非线性耦合项,首先采用数字滤波技术对系统受确定性激励的响应进行了计算;然后在数字模拟计算的基础上用嫁接的ITO积分方法对系统受随机白噪音激励的响应进行了计算。结果表明,ITO积分的综合嫁接方法有更高的计算效率,结果并表明系统的非线性耦合部分对响应有重大影响,是不能加以忽略的,本文的研究为多自由度非线性结构的响应计算提供了有用的思想和方法。

THE NONLINEAR RESPONSES OF A FORCED TWO-DEGREE-OF-FREEDOM STRUCTURE

In this paper the nonlinear responses of a forced TDOF structure are investigated. There are some highly nonlinear and coupling terms in the motion equation of the system. Firstly, the responses of the system to deterministic excitation are calculated by the Re-cursive-digital-Filtering-Technich (RDFT). Then the responses of the system to random excitation are calculated by the Simulation Method based on RDFT and the Ito's Calculus-cum-Si-mulation-Method (ICSM).The results show that the ICSM is more efficient and the nonlinear coupling terms have a significant influence on the responses of the system.This study gives some useful and efficient computation methods for nonlinear response of MDOF structure.