Numerical analysis of static and dynamic characteristics of large-span pipe-framed plastic greenhouses

With increasing demand for planting space, a new type of large-span pipe-framed plastic greenhouse has been developed in recent years. However, as the span increases, new problems in structural analysis arise. Compared with small-span plastic greenhouses, large-span pipe-framed plastic greenhouses are more likely to be damaged under wind and snow loads. In this study, the static and dynamic characteristics of a large-span pipe-framed plastic greenhouse were investigated using static analysis and the time history method, respectively. First, a 3-D finite element model of the greenhouse was established using ANSYS software. Second, the static characteristics of the greenhouse under three load cases were investigated along with and the failure mechanisms under the most unfavourable load case. Finally, the dynamic characteristics of the greenhouse were ana-lysed using the time history method. The numerical results showed that the greenhouse was mainly subjected to bending stress, and the axial stress values were small. Compared with uniform snow loads, the pipe-framed plastic greenhouse structure was more sensitive to non-uniform snow loads. The maximum displacement of the greenhouse structure under non-uniform snow loads was approximately 2.2 times that under uniform snow loads. A comparative analysis showed that the maximum displacement and bending stress obtained from the time history method were 1.7 and 1.5 times greater, respectively, than those obtained from the static equivalent method. This study provides a reference for the design and analysis of large-span pipe-framed plastic greenhouse structures.& COPY; 2023 IAgrE. Published by Elsevier Ltd. All rights reserved.