随动推力作用下细长体结构振动模态特性及稳定性分析

Vibration and Stability Analysis of the Slender Body under Follower Thrust

引入随动推力横向分量的细长体结构的振动模态特性与稳定性进行对比分析。分析结果表明:随动推力轴向分量作为保守力,引起细长体结构轴向刚度的削弱;随动推力横向分量为非保守力,使系统的动力学失稳临界值高于静态屈曲的临界值。在失稳临界点,细长体结构的1、2阶频率重合,说明随动推力横向分量引起细长体结构模态间的刚度耦合。因此,对于弯曲振动明显的细长体结构,随动推力横向分量的影响不可忽略。

The modal characteristics and stability of the slender body which can be subjected to follower thrust were compared and analyzed.It was shown that the axial component of follower thrust which was conservative would weaken the axial stiffness of the slender body.The critical value of dynamic instability of the slender body under the non-conservative transverse component was higher than its value of static buckling.At the critical point,the 1st and 2nd frequencies of the slender body remained the same.This indicates that the stiffness of different modes couples together under follower thrust.Therefore,the transverse component of thrust should be considered for the slender body,especially with obvious bending vibration.