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针对由张弦梁概念和巨型网格结构组合而成的一种新型超大跨空间结构,通过模态分析研究结构的动力特性,首先将主体结构单独承载和子结构协同承载两种情况下张弦巨型网格结构的前12阶自振周期及相应振型进行比较,然后对结构首阶各向振型的出现次序及相应自振周期进行了主体结构矢跨比、桁架梁高度、撑杆长度、预应力大小等一系列参数分析并与未布索结构作对比,详细研究了结构各方向刚度随不同参数改变时的变化情况。结果表明,主体结构单独承载时结构的纵向刚度最弱,子结构的引入能够极大地增强结构水平纵向刚度;预应力体系的引入可以显著提高结构的拱向及竖向刚度。为保证预应力提高结构竖向刚度的效果,主体结构应取较大矢跨比,且桁架梁高度的取值不宜太大。
A new type of super-long space structure, which is composed of the concept of string chord and the giant grid structure, is studied through the modal analysis of the dynamic characteristics of the structure. First, the main structure alone and sub-structure co-bearing two cases of string giant grid The first 12 natural periods and their corresponding modes are compared. Then, the order of the first-order modes and the corresponding natural periods of the structure are studied. The factors such as the ratio of the span of the main structure, the height of truss girder, the length of stay, Size and other parameters of a series of analysis and comparison with the non-cloth structure, a detailed study of the structure of the stiffness changes with different parameters when the change. The results show that the longitudinal stiffness of the structure is the weakest when the main structure is carried alone, and the introduction of substructure can greatly enhance the longitudinal stiffness of the structure. The introduction of prestressed system can significantly improve the arch and vertical stiffness of the structure. In order to ensure the effect of prestressing to improve the vertical stiffness of the structure, the main structure should adopt a larger ratio of vertical to span, and the value of truss girder height should not be too large.