周边双层中部单层球面网壳结构的自振特性分析

Self-vibration Characteristics Analysis of the Central-single-layer and Peripheral-double-layer Reticulated Dome

对周边双层中部单层球面网壳在上弦支承条件下,采用有限元理论和子空间迭代法求解了13个算例的振型和对应频率。分析了结构的频谱特性和振型特点,并详细讨论了矢跨比、双层分布范围、双层厚度对结构自振特性的影响。分析表明:单层部分是这种结构整体刚度的薄弱环节;矢跨比对结构整体刚度有明显影响,建议结构的矢跨比不宜低于1/6;双层的分部范围对结构整体刚度的影响较小,可按结构跨度的1/6-1/4确定;在上弦支承时,双层厚度对结构整体刚度的影响可忽略。

The central double-layer reticulated shell bent on supporting conditions,the finite element theory and the subspace iteration method were used to solve the 12 example and the corresponding frequency of vibration model.The structure＇s spectrum characteristics were analyzed and vibration model was discussed in detail,and the characteristic,the double rise-span ratios are distribution,double thickness of structure vibration characteristics were explored.Analysis shows that the structure of single part is the weak link of the whole stiffness,Across the whole structure stiffness ratio sagittal have obvious influence on the structure,the suggestion is unfavorable rise-span ratios are less than 1/6,Double division of the whole structure stiffness of the scope of less affected by the span structure,1/6-1/4 determined,When the wind in supporting structure,double thickness of the whole stiffness effects are negligible.