Study On Stability Bearing Capacity Of Perforated Energy Dissipation Brace

The energy dissipation brace with elliptical holes in web is a new type of energy dissipation brace.Its principle is to introduce the passive energy dissipation method into the traditional brace.Through the combination of metal damper and traditional brace,the energy dissipation of brace is realized by using metal material into plasticity.The new type of web opening yielding energy dissipation brace adopts the form of I-steel cross-section.When the brace is deformed axially,the energy is dissipated by the plate yielding between the web openings.The energy dissipation brace combines the advantages of metal damper and traditional brace,and has good ductility and energy dissipation capacity.Under the action of axial force,the stress of the plate between the notched holes of the energy dissipation brace is large on both sides,small in the middle,and uneven distribution.In order to improve the bearing capacity and energy dissipation capacity of the open energy dissipation web,and improve the uneven stress distribution of the plate around the opening,this paper changes the opening mode of the energy dissipation web,changes the slot hole into an elliptical hole,and puts forward the energy dissipation brace with an elliptical hole in the Web: the parallel double-layer energy dissipation web is connected with the middle I-steel web,and the other side of the double-layer energy dissipation web is connected with the flange plate.In this paper,the hysteretic behavior and stability of energy dissipation braces with elliptical web openings are studied by means of test and finite element analysis.The research contents are as follows:1.The low cycle repeated loading test is carried out on the energy dissipation brace with elliptical opening in web.The failure mode of the brace is explored during the test,and the energy dissipation capacity,lateral stiffness degradation mode and stress-strain distribution form of the brace under earthquake action are analyzed,so as to reveal the failure mechanism of the energy dissipation brace with elliptical opening in web under cyclic load and guide the design of energy dissipation components.2.The finite element simulation analysis of the model components with the same conditions as the test specimens is carried out to verify the correctness and applicability of the finite element model,which provides the basis for further exploring the influence of different parameters on the energy dissipation capacity of components.3.Design 20 full-scale specimens of energy dissipation braces with elliptical web openings,analyze them by using ABAQUS finite element software,explore the stable bearing capacity of energy dissipation braces with elliptical web openings by changing the slenderness ratio,the length of energy dissipation webs,the number of web layers and other design parameters,and deduce the modified calculation formula of the stable bearing capacity of energy dissipation braces based on the numerical simulation results.The results are as follows:1.The hysteretic curve of the energy dissipation brace with elliptical holes in the web is full under the low cycle cyclic loading test,which shows that the energy dissipation capacity of the component is good.The initial lateral stiffness and bearing capacity of the brace are high,and there is no obvious degradation of the strength under cyclic loading.Under low cyclic loading,the plate between the holes of the energy dissipating web plate with holes at the end first flexes and yields into plastic energy dissipation.Finally,the plate between the holes produces cracks and propagates to fracture.During this period,the I-beam of the intermediate connection is in elastic state.2.The stable bearing capacity of the energy dissipation brace with elliptical holes in the web is closely related to the slenderness ratio and the length of the energy dissipation web,and the decrease of slenderness ratio and the increase of the length of the energy dissipation web are conducive to the improvement of the stability of the energy dissipation brace,so as to provide better seismic performance.3.Based on the principle of traditional energy method,the formula of stability bearing capacity correction factor of energy dissipation braces is simple in form and easy to apply.The calculation results obtained from the modified formula have less error with the calculation results of finite element analysis,and the calculation results of the formula are more accurate,which can be used as a reference for engineering design.