振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
4期
84-89
,共6页
几何强非线性%Galerkin积分法%规范形%待定固有频率
幾何彊非線性%Galerkin積分法%規範形%待定固有頻率
궤하강비선성%Galerkin적분법%규범형%대정고유빈솔
strong geometric nonlinearity%Galerkin integral method%normal form%undetermined natural frequency
分析了覆冰导线前三阶模态中在不同水平张力下各非线性刚度项系数与线性刚度项系数的比,通过讨论水平张力,线性恢复力、非线性恢复力与振动幅值之间的关系,确定了影响覆冰导线系统几何非线性强弱的主要因素。在此基础上,应用待定固有频率法计算了系统的稳态幅值和振动频率。数值模拟表明:各模态幅值均随风速增大而增大,且当受到强几何非线性因素的影响时,各阶模态的振动频率将远离初始频率,此时传统规范形理论的分析结果难以满足模型分析的精度要求,而该研究结果则可以对模型的振动特性有比较准确地把握。
分析瞭覆冰導線前三階模態中在不同水平張力下各非線性剛度項繫數與線性剛度項繫數的比,通過討論水平張力,線性恢複力、非線性恢複力與振動幅值之間的關繫,確定瞭影響覆冰導線繫統幾何非線性彊弱的主要因素。在此基礎上,應用待定固有頻率法計算瞭繫統的穩態幅值和振動頻率。數值模擬錶明:各模態幅值均隨風速增大而增大,且噹受到彊幾何非線性因素的影響時,各階模態的振動頻率將遠離初始頻率,此時傳統規範形理論的分析結果難以滿足模型分析的精度要求,而該研究結果則可以對模型的振動特性有比較準確地把握。
분석료복빙도선전삼계모태중재불동수평장력하각비선성강도항계수여선성강도항계수적비,통과토론수평장력,선성회복력、비선성회복력여진동폭치지간적관계,학정료영향복빙도선계통궤하비선성강약적주요인소。재차기출상,응용대정고유빈솔법계산료계통적은태폭치화진동빈솔。수치모의표명:각모태폭치균수풍속증대이증대,차당수도강궤하비선성인소적영향시,각계모태적진동빈솔장원리초시빈솔,차시전통규범형이론적분석결과난이만족모형분석적정도요구,이해연구결과칙가이대모형적진동특성유비교준학지파악。
The ratio of every coefficient of nonlinear stiffness terms to coefficient of linear stiffness term at different horizontal tension levels was analysed for the first three vibration modes of an iced conductor.Through discussing the relationship among amplitude of vibration,horizontal tension,linear restoring force and nonlinear restoring force,the main factors influencing strong or weak geometric nonlinearity of an icied conductor system were determined.On this basis,the steady state amplitudes and vibration frequency of the system were calculated with the undetermined natural frequency method.Numerical results showed that the amplitudes of its vibration modes increase with increase in wind velocity;natural frequency of each vibration mode is far from its initial value when the system is subjected to the effect of strong geometric nonlinearity.The analysis results with the conventional normal form theory were difficult to meet the accuracy requirements of model analysis,but the analysis results here could grasp the vibration characteristics of the model of an iced conductor system well.