考虑节点偏差、杆件缺陷与偏心的单层三向柱面网壳稳定性研究  

STABILITY OF SINGLE-LAYER THREE-WAY RETICULATED BARREL VAULTS CONSIDERING GLOBAL GEOMETRIC IMPERFECTION,MEMBER IMPERFECTION AND ECCENTRICITY

作　　者：姜守芳[1] 李会军[1] 龙婷婷 JIANG Shou-fang;LI Hui-jun;LONG Ting-ting(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shaanxi 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：《工程力学》2022年第2期178-188,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(51408490);中央高校基本科研业务费专项资金项目(2452020168);国家级大学生创新创业训练计划项目(S202010712016);2020年教育部产学合作协同育人项目(202002116001)。

摘　　要：单层柱面网壳属于缺陷敏感型结构。为了理清节点偏差、杆件缺陷与杆件偏心对其稳定承载能力的影响程度:提出了能同时考虑三种缺陷的力学模型,并详细阐述了各种缺陷的实现方法;深入研究了三种缺陷及其耦合作用对柱面网壳稳定承载能力的影响规律;提出了确定三种缺陷最不利组合形式的方法。主要得出如下结论:柱面网壳稳定承载能力对节点偏差最为敏感,对杆件缺陷较为敏感。杆件缺陷的影响程度与节点偏差的大小有关,随着节点偏差的增大,杆件缺陷的影响程度逐渐降低;杆件的弯曲方向对柱面网壳极限荷载的影响很明显;随着杆件偏心距的增大,极限荷载近似线性地降低;与节点偏差相比,杆件缺陷与偏心对柱面网壳极限荷载的影响也相当明显,无论节点偏差大小与否,杆件缺陷与偏心对柱面网壳极限荷载的影响不容忽略;采用改进的一致缺陷模态法可高效地确定三种缺陷的最不利组合形式;随着杆件缺陷与/或杆件偏心的增大,柱面网壳的整体刚度及极限荷载逐渐降低。Single-layer reticulated barrel vaults are sensitive to imperfections.To figure out the impact of global geometric imperfection,member imperfection and eccentricity on the load-bearing capacity of reticulated barrel vaults,a model integrated with the three imperfections and the corresponding modelling procedures were clarified.The effect of the imperfections and their couplings on the stability of barrel vaults were studied.The method was developed to determine the most unfavorable combination of the three imperfections.The numerical results show that the load-bearing capacity of barrel vaults is most sensitive to the global geometric imperfection,and is obviously influenced by the member imperfection.The effect of the member imperfection is related to the magnitude of the global geometric imperfection,and becomes weaker with the increase of the global geometric imperfection.The limit load of barrel vaults is also affected by the member bowed direction.The limit load roughly linearly decreases with the increase in the member eccentricity.The effect of the member imperfection and eccentricity on the limit load is also apparent compared with global geometric imperfection,and should not be neglected whether the magnitude of the global geometric imperfection is large or small.The developed MCIMM is highly efficient to determine the most unfavorable combination of the three imperfections.The initial stiffness and limit load of barrel vaults decrease with the increase in the member imperfection and/or eccentricity.

关 键 词：单层柱面网壳 杆件缺陷 节点偏差 杆件偏心 改进一致缺陷模态法 

分 类 号：TU318[建筑科学—结构工程]