Document Type : Original Article
Authors
1 Researcher
2 Agricultural engineering research institute
Abstract
Horticultural production is faced with stress&heavy damages are caused to products annually.Use of shadehouses to reduce stress&increase product have been significantly developed in last years. Although after columns, shadehouses screens are most important part of such protected agriculture,there isn’t much information about their behavior under loads. Purpose of this article is to investigate&analyze behavior of screens when different loads are applied to them. In this research,samples of shadehouses implemented in country were examined.Stress analysis&calculation of displacement of screens according to way of installation&operation,snow load&shape of their snow removal were done using SolidWorks software.Results showed that with arrangement of distance between cenotes&the width used for nets,maximum allowable snow load is 40-52.5 kg/m2.It was also found that changing distances of columns&width of corridors can have a direct role in stability of structure while reducing the accumulation of snow,so that according to load of area,distance between columns can be adjusted in such a way that it is possible to strain with less stress in screen&the screen can be loaded. Due to not so significant differences,economic aspect can play a decisive role in selection of column distances.This issue can be considered as an advantage in screens of shadehouses. Also, calculations showed that conditions of yielding in nets are strongly affected by change of location in them.In other words,by choosing appropriate distance between columns in row of corridor&possibility of creating more rise in screens, bearing capacity will increase, but it should be noted that loading surface is wider&screens of shadehouses must bear more snow load.
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