摘要
混凝土棱柱面网壳是由曲面切割成一系列平面后,再将每块平面网格化成密肋平板并在脊线处汇交形成的一种新型混凝土网壳结构,为探讨其稳定性能,并了解结构失稳模态和失稳荷载,以及矢跨比、屋面板厚度和密肋梁、脊线梁、主拱及边梁刚度等因素对结构临界荷载的影响,本文采用有限元法进行结构弹性稳定的参数化分析。计算结果表明:结构的低阶失稳模态与柱面拱壳具有较大的整体相似性,模态最大位移主要出现在密肋平板上,设置主拱和脊线有利于提高结构刚度,弹性失稳临界荷载远大于结构的使用荷载;增大矢跨比能有效提高结构的整体刚度,建议结构的矢跨比不宜低于1/6;屋面板厚度可取网格短边尺寸的1/30;增加密肋梁的截面高度有利于提高结构的弹性稳定承载力,密肋梁截面高度可按结构跨度的1/100~1/80确定;主拱是屋盖的主要受力结构,其截面高度可按屋盖跨度的1/70~1/50确定;脊线梁和边梁刚度的改变几乎不会对结构的临界荷载产生影响。
Concrete prismatic reticulated shell is a new type of concrete reticulated shell structure,which is formed by cutting a series of planes from curved surfaces and then gridding each plane into a ribbed plate and intersecting at the ridge line.In order to discuss its stability performance,and to understand its buckling modes and loads,as well as the influence of the ratio of rise to span,the thickness of roof slab and the stiffness of ribbed beam,ridge line,main arch and side beam on the critical load of the structure,this paper adopts the finite element method to conduct the parametric analysis of the structural elastic stability.The results show that the low-order instability modes of the structure and the cylindrical arch shell have a large overall similarity,and the maximum modal displacement mainly appears on the ribbed slab.It is suggested that the ratio should not be less than 1/6;The thickness of roof plate can be determined by 1/30 of the short side of the grid.Increasing the section height of the ribbed beam is beneficial to improving the elastic stability bearing capacity of the structure.The section height of the ribbed beam can be 1/100~1/80 of the span of the structure.The main arch is the main stressed structure of the roof,and its section height can be determined according to 1/70~1/50 of the span of the roof.The stiffness change of side beam and ridge beam has little effect on the critical load of the structure.
作者
唐攒辉
张华刚
魏威
张鑫
吴琴
TANG Zanhui;ZHANG Huagang;WEI Wei;ZHANG Xin;WU Qin(Research Center of Space Structure,Guizhou University,Guiyang 550003,China;Guizhou Construction Supervision&Consulting Co.Ltd.,Guiyang 550081,China)
出处
《贵州大学学报（自然科学版）》
2019年第6期92-97,共6页
Journal of Guizhou University:Natural Sciences
基金
国家自然科学基金项目资助(51568012)
关键词
混凝土棱柱面网壳
弹性稳定
临界荷载
失稳模态
有限元法
concrete prismatic reticulated shell
elastic stability
critical load
buckling mode
the finite element method
