考虑桁架刚度的温室结构风载效应分析方法

基于位移法,在考虑桁架下弦实际刚度的基础上,提出温室结构排架柱折算刚度的概念及计算公式,给出了风荷载作用下温室结构内力和变形计算的精确方法和公式.通过近似方法、本文方法和有限元方法的对比分析,对影响温室风荷载效应的主要因素：温室桁架下弦杆截面刚度、温室的跨数进行了讨论,结果表明：提出的计算公式与有限元计算结果符合较好;拱架变形对排架内力有明显影响,工程中不能完全将拱架简化为无限刚度横梁;当连栋温室横梁轴向刚度与中间柱的抗侧刚度之比小于1 500 mm^-2 或跨数大于8时应考虑横梁变形的影响.

Analytical method for wind load effect on greenhouse structure considering of truss deformations

With the consideration of the actual stiffness of bottom chords of a truss and based on the displacement method, an accurate method as well as its corresponding formulations for a greenhouse structure analysis under wind load were presented and a concept of the equivalent stiffness of greenhouse structure was brought forward. By comparing the presented method with the approximate method and the finite element method, the main influencing factors of wind load, section stiffness of bottom chords of greenhouse trusses and the span number of a greenhouse was investigated. We concluded that the calculated results from the method presented in this paper and the FEM coincided well; the deformation of truss had a great influence to the inner force of the frame; the truss could not be considered an infinite stiffness transverse beam; the influence of the deformation of a truss should be considered in engineering design when the number of span was more than eight or the stiffness ratio of the beam and column was less than 1500 mm^-2.