CAJ | 학술논문

为研究密频结构频率密集度对结构可控性的影响,针对3自由度的密频结构,从结构基本振动方程入手,采用摄动分析方法推导了闭环系统频率、阻尼比和摄动量的相关方程.在速度反馈和状态反馈情况下,讨论了结构频率密集度对结构可控性的影响,并对不确定参数对结构模态阻尼比的影响进行了分析.分析结果表明,对于采用速度反馈、位移反馈的闭环系统,随着结构频率密集度参数的减小,结构的部分模态阻尼比逐渐趋向于零,相应的结构模态趋于不可控.考虑了结构刚度和质量参数不确定性对密频结构可控性的影响,结果表明参数不确定性会影响密频结构不同模态之间的耦合程度,进而改变结构的可控度.
위연구밀빈결구빈솔밀집도대결구가공성적영향,침대3자유도적밀빈결구,종결구기본진동방정입수,채용섭동분석방법추도료폐배계통빈솔、조니비화섭동량적상관방정.재속도반궤화상태반궤정황하,토론료결구빈솔밀집도대결구가공성적영향,병대불학정삼수대결구모태조니비적영향진행료분석.분석결과표명,대우채용속도반궤、위이반궤적폐배계통,수착결구빈솔밀집도삼수적감소,결구적부분모태조니비축점추향우령,상응적결구모태추우불가공.고필료결구강도화질량삼수불학정성대밀빈결구가공성적영향,결과표명삼수불학정성회영향밀빈결구불동모태지간적우합정도,진이개변결구적가공도.
An investigation was made into the influence of frequency intensity on the controllability of structures with closely-spaced natural frequencies. The perturbation equations were established for a closed-loop system to study the relationship of frequencies,modal damping ratios and perturbation parameters.The analysis focused on a three-degree-freedom structure with closely spaced natural frequencies. The velocity and displacement feedbacks were considered in the calculation. Several cases with velocity feedback and state feedback were considered. And the preciseness of perturbation methods was checked. The calculation results show that the damping ratios of two modes are decreasing with the decreasing of intensity parameter values of the structure with closely spaced natural frequencies, indicating that the controllability of corresponding modes is diminishing. The uncertainties in mass and stiffness matrices were also discussed in this paper. The calculation results show that the degrees of mode coupling will change due to the structural uncertainties and the controllability will be influenced subsequently.