摘要
单层网壳属于缺陷敏感结构,缺陷的存在会使得结构的稳定承载力降低,以往主流的缺陷考虑方法包括一致模态缺陷法和随机模态缺陷法,且这两种方法在缺陷引入时均假定缺陷是沿各向分布的,没有对缺陷方向做出明确说明。本文在随机模态缺陷法的理论基础上,采用有限元软件ABAQUS对700余例凯威特6型网壳进行非线性稳定分析,通过对不同方向上缺陷的引入,发现网壳节点安装偏差中的竖向偏差往往起到控制作用,仅引入节点竖向安装偏差所得的稳定承载力值接近于全方向缺陷情况,且二者的非线性屈曲模态也较为相同。同时,在竖直向缺陷与水平向缺陷共同作用下,水平向缺陷的影响会被掩盖,即在已有竖向缺陷前提下再次施加水平向缺陷对稳定承载力影响不大,二者耦合时竖向缺陷会起到控制作用。
Single-layer reticulated shell is a fault-sensitive structure,and the existence of defects will reduce the stability bearing capacity of the structure. The main methods of considering defects include uniform mode defect method and random mode defect method. Both of them assume that defects are distributed along each direction when defects are introduced. State with the tools and defect method is presented in this paper,based on the theory of more than 700 cases of Kiewitt 6 type shell,nonlinear stability analysis based on the introduction of defects in different directions. The paper found shell node installation deviation in vertical deviation control effect,often only introduce deviation from the stable installation of the vertical bearing capacity values close to the direction of all defects,and the nonlinear buckling modes of the two factors are the same. At the same time,when vertical defects and horizontal defects act together,the influence of horizontal defects will be concealed. In the presence of vertical defects,the re-application of horizontal defects has little influence on the stability bearing capacity. When the two are coupled,vertical defects also play a control role.
作者
孙一喆
惠宽堂
Sun Yizhe;Xi Kuantang(Institute of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,Shanxi)
出处
《建筑科学》
CSCD
北大核心
2020年第5期33-38,共6页
Building Science
关键词
单层网壳
随机模态法
初始缺陷
敏感性
single layer reticulated shell
random mode method
initial defect
sensitivity
