网架结构固有振动分析的分解刚度法

把矩形平面网架结构简化为夹层板,采用考虑剪切变形的具有三个广义位移的平板弯曲理论进行分析。基于分解刚度的思想提出了网架结构固有频率的计算方法,给出了八种网架结构(正放四角锥网架、两向正交正放网架、正放抽空四角锥网架、三角锥网架、三向网架、抽空三角锥网架、两向正交斜放网架和斜放四角锥网架)各阶频率的统一计算公式,对八种网架进行了固有振动分析,并与有限元分析结果进行了对比。作为一种简化的计算方法,该方法不仅计算公式简单,而且其精度比较高,误差基本在10%以内,可以为网架结构分析与设计作参考。

SPLIT RIGIDITY METHOD FOR NATURAL VIBRATION ANALYSIS OF DOUBLE-LAYER SPACE GRIDS

In this paper double-layer space grids with rectangular shape have been simplified as equivalent sandwich plate and analyzed by the non-traditional theory of plate with three generalized displacements, in which shear deformation is considered. Method for calculating natural frequency of eight types of double-layer space grids has been presented based upon the idea of split rigidity, and the uniform formula has been given out. Natural vibration analysis of those eight types of double-layer space grids has been studied with presented method. The comparison with the results of t-mite element method is given out. This simplified method is not only simpler but also of higher accuracy, whose error is less than 10 percent in general. As a result, the method in this paper can be a reference for analysis and design of double-layer space grids.