Test Research And Finite Element Analysis On The Hysteretic Behavior Of Assembled Brace Dissipated Energy By Yielded Perforated Channel Steel

The assembled brace dissipated energy by yielded perforated channel steel is proposed in this paper in order to avoid the compressional instability of the traditional concentric brace sway rod and dissipate seismic energy.The metal damper with opening is introduced into the traditional concentric brace.It has simple structure,convenient replacement,and the energy dissipation performance is excellent.Deformation is easy to observe.Double-layer perforated web is used to dissipate energy.Four web perforated channel steel are assembled at both ends of H section steel with high strength bolts.Under the action of axial force,the inter-hole plate of the web enters plastic state before the H section steel and dissipate energy.In this paper,the hysteretic behavior of assembled brace dissipated energy by yielded perforated channel steel is studied by carrying out low cycle reciprocating loading test and finite element parameter analysis.The following are the main contents:(1)A low cycle reciprocating loading test was carried out on three reduced scale specimens with different hole shapes(BCDW1～3)to study its hysteretic performance.The results show that the assembled brace dissipated energy by yielded perforated channel steel depends on the plastic deformation of the plate between the holes of the channel steel web to dissipate energy.The channel steel protects the main H section steel from deformation.The slip of the bolt will reduce the energy dissipation performance of the brace.The hole shape of channel steel web has great influence on the bearing capacity and initial stiffness of the energy dissipation brace.The brace with rhombic hole has the highest bearing capacity,and those with slotted hole has the lowest.Finite element models according to the size and the constitutive relation of steel of the test specimen are established using finite element software ABAQUS.Comparing the finite element simulation results with the test,it shows that the failure process of the finite element simulation is consistent with the test phenomenon.The obtained curves are basically consistent.The reliability of the finite element analysis results is verified.(2)Fourteen assembled brace dissipated energy by yielded perforated channel steel are designed and divided into seven groups.The influence of channel steel parameters,channel steel hole shapes and bolt hole distribution on the energy dissipation performance of the brace is studied using finite element software ABAQUS.The finite element analysis results show that the thicker and longer the channel steel web,the greater the bearing capacity and stiffness of the energy dissipation brace,and the more energy dissipated.The increase of bolt spacing will lead to slip of the energy dissipation brace,the stress of each bolt will increase,and the hole surface will be extruded and damaged.Compared with the standard bolt hole,the slotted bolt hole can improve the energy dissipation capacity of the energy dissipation brace in different scenarios.For slotted holes and elliptical holes,the bearing capacity and stiffness of the energy dissipation brace can be improved by increasing the minimum width(h_c)of plate between holes.Compared with slotted holes,the bearing capacity and stiffness of energy dissipation brace can be improved by setting elliptical or rhombic holes in channel steel web.