混凝土棱柱面网壳的几何非线性稳定性分析  

Geometric nonlinear stability analysis of concrete prismatic reticulated shell

作　　者：唐攒辉 张华刚[1,2] 魏威 吴琴 马克俭[1,2] Tang Zanhui;Zhang Huagang;Wei Wei;Wu Qin;Ma Kejian(Space Structure Research Center,Guizhou University,550003,Guiyang,China;Guizhou Key Laboratory of Structural Engineering,550003,Guiyang,China;Guizhou Construction Supervision&Consulting Co.,Ltd,550085,Guiyang,China)

机构地区：[1]贵州大学空间结构研究中心,贵阳550003 [2]贵州省结构工程重点实验室,贵阳550003 [3]贵州建工监理咨询有限公司,贵阳550085

出　　处：《应用力学学报》2020年第6期2470-2479,I0011,I0012,共12页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51568012);贵州省科学技术基金(黔科合J字[2008]2112号)。

摘　　要：混凝土棱柱面网壳是通过切割圆柱面后再网格化而得到的一种新型壳体结构。为了解其几何非线性稳定性能,采用有限元方法进行全过程分析,并在弹性稳定性分析基础上,考虑结构矢跨比、主拱刚度、密肋梁刚度、屋面板厚度、初始几何缺陷的影响进行临界荷载的参数化分析,且拟合其近似计算公式。结果表明:结构的刚度薄弱部位出现在密肋平板上,弹性失稳临界荷载约为设计荷载的6.4倍;非线性屈曲为跃越屈曲并逐步在结构中部形成软化区,临界荷载约为弹性失稳临界荷载的90%,结构具有较好的后屈曲延性;结构的矢跨比不宜低于跨度的1/6,提高矢跨比可增强结构的非线性稳定性能;主拱是结构的主要传力结构,其刚度对临界荷载的影响较大,主拱截面高度不宜低于结构跨度的1/60;密肋梁刚度对改善结构非线性稳定性的影响有限,建议密肋梁截面高度可按结构跨度的1/100~1/80取值;临界荷载近似与屋面板厚度成线性关系,但不建议采用过厚的屋面板;引入初始几何缺陷将降低结构的临界荷载5%~15%,结构最大初始几何缺陷可取跨度的1/300。本文拟合的临界荷载近似计算公式所得的结果满足工程精度的要求。The prismatic reticulated shell is a new type of shell structure obtained by cutting cylinder and meshing it,the whole process is analyzed by finite element method in order to realizing its geometric nonlinear stability,and the critical load is calculated by parameterization analysis,considering the effect of the rise-span ratio,the stiffness of the main arch,the ribbed beam,the thickness of roof plate and the initial geometric defects on the basis of elastic stability analysis,the approximate calculation formula of critical load is also fitted.The results show that the weak position of structure stiffness appears on the ribbed plate,and the critical elastic instability load is about 6.4 times of the design load.The nonlinear buckling is jump buckling and gradually forms softening zone in the middle of structure,critical load is about 90%of its in elastic instability,and this structure has good post-buckling ductility.The rise-span ratio of structure should not be lower than 1/6,and structure’s nonlinear stability can be enhanced byincreasing the rise-span ratio.The main arch is the main force structure,and its stiffness has a great influence on the critical load,the main arch section height should not be lower than 1/60 of structure span.The ribbed beam stiffness has a limited effect on improving structure’s nonlinear stability,it is suggested that the section height of ribbed beam can be 1/100~1/80 of structure span.The critical load is approximately linear with the thickness of roof plate,but it is not recommended to use too thick roof plate.The introduction of initial geometric defects will reduce critical load of structure by about 5%~15%,and the maximum initial geometric defects can be 1/300 of structure span.The approximate calculation formula of critical load fitted in this paper has corresponding engineering accuracy.

关 键 词：混凝土棱柱面网壳 几何非线性稳定性 临界荷载 参数化分析 有限元法 

分 类 号：TU375[建筑科学—结构工程]