斜拉杆增强温室双向网格型单层柱面网壳稳定性  

Tension members strengthening stability of two-way grid single-layer cylindrical shell in greenhouse

作　　者：张中昊 付强[2] 范峰[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150090 [2]东北农业大学水利与建筑学院,哈尔滨150030

出　　处：《农业工程学报》2016年第10期172-179,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：黑龙江省博士后基金项目(LBH-Z14095);中国博士后基金项目(2015M571422);东北农业大学"青年才俊"项目(518024)

摘　　要：拉杆式单层柱面网壳具有轻质、高强、透光好等优点,适用于温室结构设计。该文针对双向网格型单层柱面网壳刚度低这一特点,通过拉杆的布置方式增强结构整体刚度,基于有限元软件ANSYS及自编的前后处理程序对拉杆式温室网壳进行了弹性、弹塑性全过程分析,论证了拉杆布置方式的有效性,考察了拉杆预应力、初始几何缺陷、荷载不对称分布等因素对网壳极限承载力的影响。通过结构的失稳模态、塑性发展分布等特征响应,揭示了结构的失稳机理。为了使拉杆式温室网壳的安全可靠度得到有效的保证,采用＂3σ＂原则对塑性折减系数重新核定,取值范围为0.46-0.84。Single-layer two-way grid cylindrical shell with tension members is superior in providing high transparency,aesthetic appeal and material efficiency, and it is suitable for greenhouse structure. For testing its suitability for greenhouse use, tension member installation, tension member initial axial forces and out-of-plane tension member placement were considered in a two-way grid cylindrical surface because of the in-plane rigidity of a two-way grid shell was lower than that of a three-way grid shell. So, the single layer two-way grid cylindrical shell roof with tension members in out-of-plane and diagonal members was developed for the purpose of examining the tension member arrangement on the strength behavior of single layer cylindrical shell. A tension member＇s function was to increase the in-plane and out-of-plane rigidity of a single layer two-way grid and to improve its stability behavior. In order to understand the effect of tension members, we determined the stability of cylindrical shells based on elastic and elasto-plastic complete-process analysis by using the finite element software ANSYS and self-compiled pre-post-processing programs. Some characteristic responses such as critical loads,buckling modes and distribution maps of plastic level were collected. The effects of various geometrical and structural parameters such as initial imperfection, different supporting conditions, unsymmetrical distribution of loads, rise span ratio and tension member prestress were investigated by elasto-plastic stability analysis. In the numerical calculations, out-ofplane tension member placement caused an increase in critical load and rigidity of load-deflection relationship under symmetrical and asymmetrical loadings. The critical load of two-way grid shell increased also by the introduction of the initial axial force to tension member. The results showed that the cylindrical shells were concluded to be sensitive to initial geometric imperfection, when the rise span ratio reached 1/6, the critical loads of cylind

关 键 词：温室 荷载 壳 拉杆 临界荷载 双向网格型 弹塑性 塑性折减系数 

分 类 号：S263[农业科学—农业水土工程]