Research On Steel Frame Structure System Of Steel-Cable-Bamboo Silo

The silo structure plays an important role in grain storage.Steel skeleton has great influence on the performance of the super-large truncated cone-shaped steel-cable-bamboo silo,which is put forward by the research group.Therefore in this paper,we focus on the mechanical behavior and system selection of the steel skeleton of modular silo.Firstly,the research on the stress mechanism of the steel skeleton,including vertical grid and diagonal grid,is carried out under storage load,wind load,and earthquake.The influence of connection mode between beam and column on the structural performance of the steel skeleton is studied.Secondly,controlling the stress ratio of each component in the same range and considering the impact of distance of the ring beam,the number of the column and the type of the section type,two kinds of steel skeleton structure are selected and analyzed in detail.An economic index of the silo is given and the influence of the height-diameter ratio on it is studied.The suggestion for the selection of the steel skeleton is given comparing the advantages and disadvantages of the two kinds of steel skeleton.Finally,the nonlinear bearing capacity of two kinds of steel skeleton under storage load is analyzed considering the influence of large deformation and material elastic-plastic.The failure mechanism and ductility performance of the steel skeleton are studied.The method of enhancing the ductility performance of two kinds of steel skeleton is put forward after defining the ductility coefficient of silo structure under storage load.The ductility performance of two kinds of steel skeleton is compared and analyzed.Through these series of studies,we can reach the following conclusions:(1)The mechanical behavior of the steel skeleton structure of the modular silo is reasonable.The storage load is the main load and the ring beam is the main bearing member.The connection mode between the beam and column of vertical grid should be fixed while the connection mode between the beam and column of diagonal grid should be articulated.The steel skeleton of diagonal grid has greater lateral performance.(2)Controlling the stress ratio of each component between 0.75 and 0.8,the most reasonable selection of the steel skeleton is as shown below.The member section is pipe,the distance of the ring beam is 2m,there are 60 columns in vertical grid while 60×2 columns in diagonal grid.(3)The steel consumption per unit volume is used as an economic index.The greater the height-diameter ratio is,the poorer the economical efficiency is.When the height-diameter ratio less than 1,the steel skeleton of vertical grid is superior.Otherwise,the steel skeleton of diagonal grid is superior.(4)Brittle failure happens in two kinds of steel skeleton under nonlinear analysis.Among them,the column is damaged before the ring beam in the steel skeleton of vertical grid,causing the structural instability.In the steel skeleton of diagonal grid,when the plastic hinge appears in the ring beam,the structure becomes a mechanism,which leads to the structural instability.(5)The ductility performance of the steel skeleton of vertical grid should be enhanced by adjusting the cross section of the column.While the ductility performance of the steel skeleton of diagonal grid should be enhanced by changing the connection mode between beam and column and adjusting the cross section of the member.After the adjustment,the ductility coefficient of the vertical grid increases by 2.4 times while the ductility coefficient of the diagonal grid increases by 2 times.(6)After enhangcing the ductility performance,When the height-diameter ratio less than 1,the steel skeleton of diagonal grid has greater ductility performance.Otherwise,two kinds of the steel skeleton is close.The steel skeleton of diagonal grid is superior than the steel skeleton of vertical grid considering the steel consumption per unit volume.