Abstract:

In order to optimize the weak links of the steel structure of the multi-span film greenhouse, this study focuses on an 8-meter-span multi-span film greenhouse in Suqian, Jiangsu Province, and employs an importance coefficient analysis method along with the finite element software Midas-Gen to conduct stability analysis and optimization design. Based on local climatic conditions and relevant standards, multiple loads including non-uniform snow loads were calculated. A finite element model was established with a simplified greenhouse structure to analyze stress distribution and deformation characteristics under different load combinations. Results indicate that uneven snow load causes stress concentration at the gutter, with peak deformations of the roof arch and bottom chord reaching 19 mm and 18 mm, respectively close to the code-specified allowable limits. To prevent structural instability, an optimization strategy was proposed: adding vertical supports between the secondary arches and the bottom chord to enhance the roof's deformation resistance, while reducing the cross-section of the main columns to improve material efficiency. After optimization, the peak deformations of the roof and bottom chord were reduced to 12.27 mm and 3.22 mm, respectively, with a notable improvement in stress distribution. This study demonstrates that reinforcing key components and adjusting cross-sections can effectively enhance the progressive collapse resistance of multi-span greenhouses.

Key words: multi span film greenhouse, structural optimization, finite element analysis, stress concentration, deformation control