Stability design methods for steel frame of agricultural gutter-connected greenhouse

Stability analysis is the key step in gutter-connected greenhouse structure design. The traditional theories of stability analysis of steel structure of civil engineering are used in agricultural greenhouse structure design in China at present. The theories being used can not reflect the real mechanical reaction characteristics of the greenhouse structure in which the small thin-walled section was used. The steel consumption is increased meanwhile. The latest theoretical research and practical achievements were utilized, and the traditional length coefficient method and revised length coefficient method were analyzed in detail. Based on that all types of greenhouses are of equal height, and the lateral buckling of frames has overall nature, this paper proposed the new methods for checking the stability of greenhouse steel frame, revised effective length coefficient method and storey-based stability coefficient method which considered the inter-action between columns during overall buckling with the help of theoretical analyses and comparisons of a large amount of finite element calculations. On the condition that side post and mid-post of most greenhouses use different sections at present the proposed methods can get better technical and economical effects in the design of greenhouse steel structure frame.