大开口车辐式索承网格结构静力性能影响因素分析

Static performance parameter analysis of large opening spoke-wheel-type cable supported grid structure

为了深入了解大开口车辐式索承网格结构的静力性能,借助弹塑性非线性全过程分析,分别对索杆体系预张力大小、撑杆高度、外边界环梁高差、环索平面形状、刚性网格矢高、刚性网格形式、刚性网格肋梁曲率及内环高差等影响因素进行分析。分析结果表明:索系预张力主要影响结构的初始形态;增加撑杆高度和刚性网格矢高都能有效地提高结构的刚度和承载力;合理选取边界环梁高差及环索平面形状,可以使得车辐式索杆体系的传力更高效,有效降低索的张力水平;带斜杆的刚性网格对结构刚度和承载力更有利;适当增加肋梁曲率,可提高结构承载力,增大刚性网格刚度;刚性网格内环高差对结构静力性能影响较小。

In order to better understand the static performance of large opening spoke-wheel-type cable supported grid structures, a parametric study was carried out by means of nonlinear analysis. The parameters considered include pretension, strut height, height difference of boundary ring beams, shape of hoop cable, rigid frame rise, rigid grid configuration, rigid grid rib beam curvature, and inner ring height difference. The results show that the pretension of the cable system provides the initial stiffness of the structure;increase the strut height and rigid frame rise can be very effective in improving the stiffness of the structure;reasonable selections of the height difference of the boundary ring beams and shape of hoop cable can make the spoke cable system more efficient, thus effectively reducing the level of cable tension;rigid grids with diagonal bracings are more favorable in terms of structural stiffness and resistance responses;appropriately increasing the curvature of the rib beam can increase the ultimate bearing capacity and increase the stiffness;the height difference of the inner ring of the rigid grid has little effect on the overall structural performance.