Study On Stability And Seismic Performance Of Venlo Greenhouse Considering Skin Effect

Greenhouse structure,as a typical productive building,is widely used in China due to its periodic annual production characteristics,playing an important role in achieving agricultural modernization and promoting rural economic development.But with the continuous popularization of Venlo type greenhouses in China,their uses and forms are also constantly diversified.In addition,greenhouses have strong regional characteristics,and there are also many safety hazards.And in existing design analysis,most of them use greenhouse frames for analysis,but the actual skin effects such as wall frames and glass are not considered.This article takes this as the research background,combines with specific engineering,and considers the skin effect of the structure.Through simulation analysis of nearly 2000 Venlo greenhouse structural examples,it focuses on studying the influence of skin effect on the static performance,static stability,and seismic performance of Venlo greenhouse,and discusses and verifies the influence of node installation deviation on the structural bearing capacity.Obtain the following conclusion.(1)The skin effect of the Venlo greenhouse has a significant impact.By comparing and analyzing the static performance of greenhouse frame structure and space skin structure under various working conditions,the results show that the displacement of space skin structure is much smaller than that of the frame structure,and the maximum displacement is also reduced by about 2.49 times.Therefore,in the process of structural design,appropriate consideration should be given to the beneficial effects of skin effects on the structure.(2)The installation deviation of nodes has a significant impact on the nonlinear stability bearing capacity of greenhouse structures.As the span increases,the higher the sensitivity of Venlo greenhouse structures to defects,the greater the decrease in bearing capacity.Through extensive numerical analysis,it has been shown that the reduction in bearing capacity of structures with a span of 6.4m after the introduction of defects ranges from 0.23% to 11.93%,from 11.54% to 37.43% for structures with a span of 9.6m,and from 18.46% to 50.22% for structures with a span of 12.8m.(3)Artificial neural networks can effectively predict the ultimate bearing capacity of greenhouse structures.In response to the difficulty in verifying and promoting the bearing capacity of greenhouse structures,artificial neural networks are used to fit the structural ultimate bearing capacity samples obtained based on node installation deviations,and a large number of data samples are trained and learned.The results indicate that the average error between the artificial neural network and finite element analysis is 2.01%,which can be used as a method for calculating the ultimate bearing capacity of structures.(4)The skin effect can effectively reduce the displacement of Venlo greenhouse structures under earthquake action and improve the stiffness of the structure.By comparing and analyzing the dynamic response of empty frames and spatial skin structures,it was found that seismic action has become the main control factor for column top displacement.Under the 8-degree 0.3g seismic intensity,the column top displacement has exceeded the requirements of the specifications,and seismic action needs to be considered.However,the column top displacement and interlayer displacement angle of the spatial skin structure are always smaller than those of the empty frame greenhouse structure.At the same time,the maximum acceleration amplification coefficient of the spatial skin structure is also greater than that of the empty frame,indicating that the skin effect can effectively improve the stiffness of the structure.