Development And Performance Research Of Prefabricated Framework For Solar Greenhouse

Sunlight greenhouses are widely used in northern my country,and they are also an important part of my country’s facility agriculture sector.The research on the roof skeleton of sunlight greenhouses mainly focuses on the overall mechanical performance and optimization of the skeleton and the development of new skeletons.The prefabricated frame of the solar greenhouse has the advantages of light weight,flexible layout,no welding,and fast on-site installation in factory prefabrication,which is suitable for mass promotion and use.At present,there are few researches on the fabricated framework of solar greenhouses.The prefabricated skeleton nodes are related to the safety of the entire greenhouse,and the importance is self-evident.Therefore,the development and performance research of the fabricated framework of solar greenhouses is very important.Based on this,this article first uses the sunlight greenhouse lighting theory to design the curvature of the sunlight greenhouse skeleton suitable for Shaanxi;develops three types of assembled skeletons(ellipse,round steel pipe,and a few characters)and develops assembly nodes for them;through finite element software ANSYS WORKBENCH studies the mechanical performance of the fabricated framework;finally,the reliability and feasibility of the finite element numerical simulation are verified through static tests.The research shows that:(1)According to the solar greenhouse lighting theory and skeleton load design theory,the front roof curvature of the solar greenhouse and the solar greenhouse skeleton load design values suitable for Shaanxi are derived,which provides a theoretical basis for the development of the prefabricated skeleton.(2)Developed three types of prefabricated frameworks for solar greenhouses: prefabricated elliptical frameworks,prefabricated round steel pipe frameworks,and prefabricated several-shaped frameworks;designed assembling parts for the developed prefabricated frameworks: the elliptical framework uses built-in oval tubes Fittings,round steel pipe skeleton nodes use outer sleeve fittings,and a few-shaped skeleton joints use built-in hollow cuboid fittings;and the length of the three types of assembled skeleton joints is 10 cm,which is the same thickness as the skeleton.(3)Analyze the force performance of the developed three assembled skeletons and assemblies through finite element software.It is found that under the most unfavorable load,the maximum stress of the fabricated elliptical frame,fabricated round steel pipe truss frame,and fabricated truss frame is far less than the steel design strength,and the deformation is far less than the allowable deformation of the solar greenhouse,and the two assembly The stresses on the assembly parts and bolts at the location are less than the maximum stress of the skeleton,indicating that the assembly joints are safe and feasible.(4)Under the most unfavorable load,the force and deformation analysis of the three types of assembled skeletons and unassembled skeletons found that there is almost no difference between the assembled skeleton and the unassembled skeleton in terms of overall deformation and stress.It shows that the fabricated frame can be used instead of the unassembled frame;evenly distributed load is applied until the three types of fabricated frame fail,and it is found that the fabricated round steel pipe truss structure can withstand a larger load;the fabricated double-shaped frame shows deformation failure,ellipse The skeleton and the round steel tube truss structure showed failure to reach the design strength;comparing the three types of prefabricated skeletons,it was found that the prefabricated three-shaped skeleton had poor performance in terms of force and deformation resistance.(5)The static bending test and the finite element numerical simulation of the elliptical steel pipe joints were carried out,and the output results of the two were compared and analyzed,and the relative error between the static test data and the output data of the finite element software was found to be within 3%,which confirmed the ANSYS software Study the feasibility and reliability of the framework and nodes of the solar greenhouse.The optimization of the section of the elliptical steel pipe found that when the main pipe section is 10°,the stress on the assembly is smaller;the elliptical steel pipe section is made into an occlusal shape,and it is found that when the l is 15 mm,the force performance of the elliptical steel pipe assembly is the best.