日光温室前屋面支撑位置对实腹式骨架安全性的影响  

Influences of south roof support position change on the skeleton structure safety in solid belly solar greenhouse

作　　者：齐飞 闫冬梅 魏晓明 Qi Fei;Yan Dongmei;Wei Xiaoming(Academy of Agricultural Planning and Engineering,MARA,Beijing 100125,China;Key Laboratory of Farm Building in Structure and Construction,MARA,Beijing 100125,China)

机构地区：[1]农业农村部规划设计研究院,北京100125 [2]农业农村部农业设施结构工程重点实验室,北京100125

出　　处：《农业工程学报》2020年第16期174-181,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2017YFD0701500)。

摘　　要：为掌握日光温室前屋面支撑点设置位置对骨架结构安全性的影响规律,获得最佳支撑点位置设置区域,该研究以北京地区为例,选取8、9、10 m三种常见跨度的日光温室为研究对象,依据相关设计规范提出了3种跨度日光温室的建筑剖面并确定了荷载作用形式。假定在日光温室前屋面骨架设置一个支撑点,并且支撑点位置可以沿着前屋面骨架以每隔一段相对固定的距离(约为50 cm)进行变化,运用MIDAS-Gen软件分别计算对应的49种支撑工况、255种荷载组合下温室前屋面骨架的宽厚比、挠度和应力比系数等强度及稳定性指标。计算发现,在不同支撑工况和荷载组合下,分别选取70mm×50mm×2.0 mm、80 mm×60 mm×2.0 mm、90 mm×60 mm×2.0 mm作为8、9、10 m跨日光温室的实腹式主拱架截面,对应的拱杆宽厚比为33、38、43,挠度值最大为15.13、14.69、18.5mm,均满足规范要求。温室前屋面支撑点位置变化对骨架安全性产生显著的影响,挠度变形、应力比系数随支撑点位置的变化规律均呈现出"孤峰型"曲线特征,且3种跨度温室的曲线规律基本一致,在峰值附近是最佳的支撑设置区域,其中8、9、10 m跨日光温室相对于前屋面投影的最佳相对支撑位置分别为51%、72%和71%,在此位置区域内增加支撑可降低日光温室拱杆应力,减小挠度值。研究结果可为指导日光温室应急防灾、实腹式骨架系统研发等提供参考。Structure of solid-belly skeleton is commonly used for the solar greenhouses with light loading or narrow span due to the small section stiffness. Generally, a suitable support can be set at a certain position of south roof in a solar greenhouse, aiming to provide an economically feasible technical solution to the improvement on the safety of entire skeleton system. In this study, three types of solar greenhouse with a common span in Beijing were selected as research examples, and then to calculate the section parameter of greenhouses and the loading form, according to greenhouse design code. The main purpose of this study is to determine the impact of setting position for south roof support point on the framework safety, and thereby to obtain the optimal setting region of support point. Prior to the calculation, it needed to assume that a support point was set on the south roof skeleton of a solar greenhouse, and the position of support point can be changed along the south roof skeleton at a relatively fixed distance(about 50 cm). A Midas Gen software was then used to calculate the width-to-thickness ratio, deflection, and safety factor of south roof skeleton in the solar greenhouse under 49 supporting conditions, and 255 load combinations. The results of south roof skeleton for the 8, 9, 10 m span solar greenhouse were the width-to-thickness ratios of 33, 38, 43, and the maximum deflection of 15.13 mm, 14.69 mm, 18.5 mm, under different supporting conditions and load combinations, for the section size as 70×50×2.0, 80×60×2.0, 90×60×2.0, respectively. Compared with the greenhouse design codes, all obtained data demonstrated that the skeleton structure can meet the required level of safety and stability, as the support position of south roof changed in this case. Based on the above analysis of deflection deformation and safety factor on the south roof skeleton with different support positions, it was founded that the change of support positions can make a significant impact on the safety of a south roof ske

关 键 词：温室 设计 农业 实腹式骨架 前屋面支撑 

分 类 号：S26[农业科学—农业水土工程] TU261[农业科学—农业工程]