基于能量的大跨结构的旋涡脱落共振实用分析

Practical Analysis of Crosswind Resonance on Large-span Structures with Cables Based on Energy

采用基于最大位移时能量相等原理 ,首次建立了振动过程中等效线性化法的弹性模量修正公式进行实用分析 .以受拉二力杆单元取代索的单元的准线性结构采用试算法计算出结构横风向共振的临界风速 ,并与原含索非线性结构用ANSYS程序进行时程分析的数值结果进行了比较 .结果表明 ,采用以模量修正的受拉二力杆单元取代索单元的准线性结构精度良好 ,试算临界风速时的工作量显著减少 ,为类似问题提供参考 .

In this paper,authors establish a Ernst formula for revising elastic modulus for the first time that is applied to the process of vibration,based on the theory of energy equivalent at maximum displacement.The critical velocity v c of the crosswind resonance is determined by trying for a quasi-linear structure in which cable elements are replaced by tension-only spar elements,and calculational values are compared between the quasi-linear structure with tension-only spars and the nonlinear structure with cables.The results show that the quasi-linear structure in which cable elements are replaced by tension-only spar elements has a high precision by means of revising elastic modulus and a work reduced obviously in determining the critical velocity.The Ernst formula for revising elastic modulus in the process of vibration in the paper can be applied in the equivalent linearization method of similar nonlinear dynamic analysis.