基于构形易损性理论的温室单层球面网壳极限承载力分析  

Load-Bearing Capacity Analysis of Greenhouse Single-Layer Reticulated Domes Based on Form Vulnerability Theory

作　　者：卢珍 李会军[1] 饶颢 LU Zhen;LI Huijun;RAO Hao(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《建筑钢结构进展》2020年第2期18-24,共7页Progress in Steel Building Structures

基　　金：国家自然科学基金(51408490)。

摘　　要：温室单层球面网壳的稳定性在设计中起着控制作用,尤其是非对称(半跨均匀)荷载、初始几何缺陷(节点偏差)、矢跨比和拉索预应力等因素对温室单层球面网壳稳定性的影响还有待深入研究。基于构形易损性理论,提出了判断参数对极限承载力影响的指标,即节点构形度的差异系数。利用ANSYS软件对矢跨比分别为1/3、1/5和1/7的K6、K8型温室单层球面网壳进行了整体刚度矩阵的提取,并通过MATLAB自编程序计算得到节点构形度的差异系数,定性分析了各参数对极限承载力的影响与节点构形度的差异系数的关系。研究表明:判定初始几何缺陷和不对称荷载对温室单层网壳结构极限承载力影响的准则是节点构形度的差异系数越小,结构的极限承载力越大;通过对K6型和K8型温室单层球面网壳的稳定承载力进行计算,验证了提出的判别准则的适用性与合理性。提出的判别准则可推广至其他类型的大跨度温室空间结构中。The stability of shell structures plays a significant role in the design of greenhouse single-layer reticulated domes.The stability is governed by many kinds of factors,for instance,asymmetric(half-span uniform)load,initial geometric defect(node deviations),rise-span ratio and cable prestress.These factors need to be further researched.Based on the form vulnerability theory,an index for determining the influence of parameters on load-bearing capacity is proposed in this paper,namely,the difference coefficient of nodal well-formedness.The whole stiffness matrix of K6,K8 greenhouse single-layer reticulated domes with three rise-to-span ratios(1/3,1/5 and 1/7)are extracted using ANSYS software,then the different coefficients of node well-formedness are computed through MATLAB self-programming,and the relationship between the influence of various parameters on load-bearing capacity and the difference coefficient of node well-formedness qualitatively are analyzed.Research results show that the criterion for determining the influence of initial geometric defect and asymmetric load on load-bearing capacity of the single-layer reticulated dome is,the smaller the difference coefficient of the node well-formedness,the greater load-bearing capacity of the structure.Through the calculation of load-bearing capacity of the K6 and K8 greenhouse single-layer reticulated domes,the applicability and rationality of the proposed criterion are verified.The proposed criterion can be extended to other large-span space structures of greenhouse.

关 键 词：单层球面网壳 构形易损性理论 节点构形度 差异系数 初始几何缺陷 不对称荷载 极限承载力 

分 类 号：TU311.2[建筑科学—结构工程]