Experimental Research On Mechanical Properties Of The Clolume Base Joint Of Steel Storage Racks In Automated Warehouse

In recent years,The warehousing industry has developed rapidly in China.The steel storage racks has a huge market demand and is widely used in the logistics industry.The mechanical properties of the clolume base joint of steel storage racks have a great influence on the overall performance of the warehouse.In this article,detailed experimental and theoretical researches have been carried out on two types of clolume base joints including column-plate welded and assembled-disconnected.Firstly,low-cycle repeated displacement loading tests are performed on two types of clolume base joints including column-plate welded form and assembled-disconnected form.Test and record the stress failure of six groups of clolume base joints.The test data is analyzed and processed to obtain the bending moment angle relationship,skeleton curve,joint stiffness,equivalent viscous damping coefficient,stiffness degradation,displacement ductility coefficient,and energy dissipation capability.Then,finite element simulation analysis is performed on the two sets of clolume base joint specimens,and the skeleton curve,deformation status and stress concentration position of the joints are compared with the test results to verify the rationality of the finite element model.Finally,on the basis of experimental data and finite element simulation results,select several parameters that have a great influence on the performance of the clolume base joints.A parametric analysis model is established to compare the bearing capacity,bending stiffness and failure mode of each model.Summarize the influence of each parameter and the force performance of the clolume base joints and give the suggestions of parameters selection of the clolume base joints in actual project.The main conclusions are as follows:(1)The double-sided welding form has effectively improved the bearing capacity,stiffness,ductility and energy dissipation capacity of the clolume base joints.(2)The load capacity and stiffness of clolume base joint of column-plate welded form are stronger than that of assembled-disconnected form.The ductility is weaker than that of the assembled split column base joints,and the maximum energy dissipation capacity is equivalent.(3)The load-bearing capacity,failure mode and bending moment curve obtained from the finite element simulation of the two types of column clolume base joints are in good agreement with the test results,which verifies the rationality of the finite element model.(4)Increasing the thickness of the bottom plate increases the force performance of the column base joints.The stress performance of the nodes tends to be stable when the plate thickness is increased to 16 mm,and as the increase of the thickness of he plate.The improvement of carrying ability is not obvious.The base plate thickness of the column base joint is 16 mm.(5)The equivalent stiffness of the column base joints increases when the spacing of chemical anchor bolts decrease.When the anchorage spacing is reduced to 9D,the equivalent stiffness of the column base joints reaches a maximum value and tends to be stable;The greater the eccentricity of the chemical anchor bolt,the smaller the equivalent stiffness of the node.It is recommended to take 9D between the chemical anchor bolts and the upright columnar heart on the same line.