Document Type : Original Article

Authors

• Ghasem Zarei ¹
• Jalal Javadi Moghaddam ²
• Sayed Moin‐eddin Rezvani ¹

¹ Researcher

² Agricultural engineering research institute

Abstract

The production of horticultural products is faced with environmental stress; and heavy damages are caused to the products every year. The use of shade/net houses to reduce stress and to increase the quantity and quality of the product have been significantly developed in the last few years. Although after the columns, screens of the shade/net houses are the most important part of such protected agriculture, there is not much information about their behavior under the loads. The purpose of this article is to investigate and analyze the behavior of screens when different loads are applied to them. In this research, the samples of shade/net houses implemented in the country were examined. The stress analysis and calculation of the displacement of the screens according to the way of installation and operation, the snow load and the shape of their snow removal were done using SolidWorks software. The results showed that with the arrangement of the distance between the cenotes and the width used for the nets, the maximum allowable snow load is 40-52.5 kg/m². It was also found that changing the distances of the columns and the width of the corridors could have a direct role in the stability of the structure while reducing the accumulation of snow, so that according to the load of the area, the distance between the columns could be adjusted in such a way that it was possible to strain with less stress in the screen and the screen could be loaded. Having no significant differences, the economic aspect can play a decisive role in the selection of column distances. This issue (changing the width of the columns) can be considered as an advantage in screens of shade/net houses. Also, the calculations showed that the conditions of yielding in the nets were strongly affected by the change of location in them. In other words, by choosing the appropriate distance between the columns in the row of the corridor and the possibility of creating more rise in the screens, the bearing capacity would increase, but it should be noted that the loading surface is wider and the screens of shade/net houses must bear more snow load.

Keywords

• Controlled Agricultural Environments
• Loading
• Protected Agriculture
• Screen/Net
• Simulation