随机节点位置安装偏差与杆件偏心对单层球面网壳承载力的影响研究  

Effect of random nodal deviation and member eccentricity on load-carrying capacity of single-layer dome

作　　者：李会军[1] 王超[1] 肖姚 LI Huijun;WANG Chao;XIAO Yao(College of Water Resources and Arehileclural Engineering,Northwest Agriculture and Forestry 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

出　　处：《建筑结构学报》2020年第2期134-141,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51408490);国家留学基金项目(201706305044);大学生创新创业训练计划项目(201710712046)

摘　　要：单层球面网壳属于缺陷敏感性结构,其稳定承载能力受各种缺陷影响。为量化节点位置安装偏差缺陷、杆件对节点的偏心缺陷及其二者耦合作用对网壳稳定承载力的影响程度,对1000个随机产生的K6型单层球面网壳展开深入研究。首先提出了能够考虑随机节点安装偏差、随机杆件偏心的力学模型,然后阐述了两种随机缺陷在数值计算中的实现方法,最后获得了不同大小的节点安装偏差、杆件偏心距对单层网壳稳定承载力的影响程度与规律。计算结果表明:节点安装偏差对网壳极限荷载的影响更为显著,杆件偏心对极限荷载的影响相对较小;当节点安装偏差较小时,杆件偏心对网壳极限荷载的影响更为显著;节点安装偏差相同时,杆件偏心越大,网壳极限荷载越小。当最大节点安装偏差R1=2 cm、最大杆件偏心R2=10 mm时,缺陷网壳的极限荷载较理想网壳平均下降了10.94%;当R1=4 cm、R2=10 mm时,极限荷载平均下降了16.43%。Single-layer spherical reticulated dome is sensitive to imperfections,and its stability is affected by several imperfections in different levels.To quantify the influence of nodal deviation,member’s eccentricity to node and their coupling effects on load-carrying capacity of dome,1000 randomly generated K6 single-layer spherical reticulated domes were taken as numerical examples.Firstly,a mechanical model which could consider random nodal deviation and member’s eccentricity simultaneously was developed.Then,realization procedures to aforementioned two imperfections were clearly illustrated.Finally,the effects of two imperfections with different magnitudes on loadcarrying capacity of reticulated domes were investigated.The numerical results are obtained as follows:nodal deviation has evident effect on load-carrying capacity of reticulated domes,while member eccentricity has relatively slight influence.Member eccentricity has more effect on the ultimate load of reticulated dome with smaller nodal deviation.For the same magnitude of nodal deviation,the greater the member eccentricity,the smaller the ultimate load of reticulated dome.Compared with ideal dome,the imperfect dome has an ultimate load reduction of 10.94% averagely for R1=2cm and R2=10 mm,and 16.43%averagely for R1=4 cm and R2=10 mm,where R1 and R2 are the maximal nodel deviation and member’s eccentricity to node,respectively.

关 键 词：球面网壳 节点偏差 杆件对节点偏心 稳定承载力 

分 类 号：TU393.3[建筑科学—结构工程] TU312.1