Study On Seismic Performance Of Perforated Buckling-Restrained Brace With H-Section Steel Core

Earthquakes are very likely to cause serious damage or even collapse of structures.Post earthquake repair of structures is extremely difficult.With the development of the society,people have put forward more stringent requirements for the safety and applicability of the seismic design of buildings.The buckling restrained brace develops rapidly in recent years,as a typical application of energy dissipation and damping design.At present,the materials and forms of the buckling restrained braces have been deeply studied by scholars at home and abroad,and there is a need to reinforce the end of the brace.Referring to the design idea of "local weakening equivalent to end strengthening" proposed by Professor Zhou Yun and others,this paper reconstructs the buckling restrained brace of the common H steel core,puts forward a new type of perforated H-section buckling restrained brace,and carries on the research in order to provide theoretical support for the future design work.The finite element analysis of the new perforated buckling restrained brace is carried out by the ABAQUS finite element software.The influence of the parameters such as area ratio,length-width ratio,the number of opening holes on one side,spacing ratio,gap and slenderness ratio on load capacity,stress distribution and hysteretic energy dissipation performance are obtained.The finite element simulation results show that the load capacity of the new perforated buckling restrained brace is strong,the stress distribution is uniform,the hysteresis curve is full,the energy dissipation performance is excellent,and the effect of fixed point yield is achieved.With the increase of the area ratio,the load capacity of the brace gradually increases and the hysteresis performance increases first and then decreases.With the increase of the length width ratio,the load capacity and the hysteresis performance increases first and then decreases.With the increase of the number of opening,the load capacity increases first and then decreases,and the hysteresis performance gradually decreases.With the increase of spacing ratio,the load capacity and hysteresis performance first increases and then decrease.With the increase of the gap,the load capacity first decreases and then decreases,and the hysteresis performance gradually decreases.With the increase of the slenderness ratio,the load capacity and hysteresis performance all increases first and then decreases.By comparing and analyzing the finite element results,this paper suggests that the area ratio should be 70%,the ratio of length to width should be 2.6,the number of opening holes on one side should be 4(the number of open holes should be 8),the spacing ratio should be 18%,the gap should be 2mm,the slenderness ratio should be 57.When the accuracy of gap can not meet the requirements of 2mm,5mm chould be taken,which can also meet the requirements of load capacity and hysteretic behavior.In order to prevent the failure of the end,it is suggested that the area ratio should not be 90%,the ratio of length to width should not be 0.9,the number of open holes on one side should not be 1~3(when the number of open holes is 2~6),the spacing ratio should not be 54%,the gap should not be 1mm.In order to prevent the partial failure between holes,spacing ratio should be avoided to take 9% and the following values.In order to prevent local buckling on both sides of the hole,the slenderness ratio should be avoided to take 85 and above.