Research On Stability Of Steel Rack Multi-Roll Lipped Column And Program Realization

With the rapid development of the logistics industry,the automatic warehouse storage racks become more and more extensive.However,at present,the guidance of the relevant code on storage design is lagging behind,and the impact of opening on stability of multi-roll lipped column is not considered enough.There are many shortcomings in the actual use of code,besides,there is no professional design software for steel storage design in the market.Firstly,the buckling mode of multi-roll lipped column is analyzed.Then the influence of the type of section,the thickness of the section and the form of opening on the stability of multi-roll lipped column with different length are studied by ABAQUS.Then further study is made on the influence of opening on web and flange and arrangement of opening.And the formula of the opening reduction coefficient K is obtained by the calculation results.Next,based on design software of steel storage racks SSFD developed earlier by project group and the research results of multi-roll lipped column with hole in this paper,the SSFD software are analyzed and improved.Finally,the SSFD software is used to study the effects of the structural arrangement of the storage,the arrangement of the back support and the height of the column on the mechanical properties of the steel storage.The variation regulation of the mechanical properties of the steel storage under the influence of various parameters is analyzed.And the structural optimization scheme is obtained.By the studies above,the main conclusions of this paper are as follows:（1）The stiffener and rolled lip of the cross section of multi-roll lipped column can effectively strengthen the local buckling stability.With the increase of the length of column,the buckling mode changes from interaction of distortional and local buckling to interaction of distortional and global buckling.And finally the buckling mode is controlled by the global buckling.With the length of column increasing and the buckling mode changing,the opening reduction coefficient go through decrease-increase-decrease-increase procedure.（2）The section size,section thickness and the form of hole have little influence on the variation of opening reduction coefficient.The opening reduction coefficient is negatively correlated with the opening rate,and less correlated with the the thickness of the cross section and the spacing of the opening.The opening of the web has an effect on the bearing capacity of the multi-roll lipped column with different buckling modes.The opening of the flange and the arrangement of the opening of the web and the flange have an influence on the bearing capacity of the multi-roll lipped column controlled by the distortional buckling.（3）The formula for calculating the opening reduction coefficient of the multi-roll lipped column is presented.K=1.55-0.00235r-12.67β+1.727×10^-5r²+0.005854rβ+76.95β²-5.392×10^-8r³+4.654×10^-5r²β-0.04385rβ²-149β³.In this formula,r is the ratio of the length of the component to the radius of gyration,andβis the opening rate.（4）The improved SSFD software can efficiently realize the establishment,analysis and parametric analysis of the finite element model of the automatic warehouse steel storage.（5）The back support is unnecessary to be set when the layer of single-raw and standard rack is not more than 5;when the layer of single-row and standard storage racks is more than 5,the back support should be set.The height of the back support layer should be 2 times the height of the lattices,and the horizontal brace should be arranged in the same row of back support.The maximum stress ratio of column is affected by the height of the lattices and the height of the bottom column.For the single-row storage racks 0.5m of the height of the bottom column and 2.1m of the height of the lattice should be the best.The standard storage racks is most suitable for the collocation that the height of the bottom column is 0.5m and he height of the lattice is 2.4m.