| Thin steel plate shear wall structure is a kind of lateral force resistant structural system for high-rise and super high-rise buildings,it has a high bearing capacity,high stiffness,and good seismic performance,etc.,but the previous research found that thin steel plate shear wall has some shortcomings.Firstly,the thin steel plate shear wall mainly relies on the yielding of the embedded steel plate tension band to dissipate the seismic energy,the real plastic deformation of the energy dissipation is the embedded steel plate diagonal tension band and the central area,the remaining area of the embedded steel plate does not give full play to the role of the waste of materials.Secondly,the formation of the main diagonal tension band of the thin steel plate under the action of large earthquakes is similar to the role of diagonal bracing,but the loadbearing capacity of the tension band is not as high as the load-bearing capacity of the buckling restrained brace.Finally,thin steel plate shear walls are mainly in the form of embedded steel plates that yield and dissipate energy during earthquakes,while the main body of the steel frame beams and columns are only slightly damaged and can be reused after a simple repair.Therefore,based on the structural stress mechanism and damage pattern of thin steel plate shear walls,this paper removes the part of the steel plate shear wall where the embedded steel plate does not fully function under reciprocating load,leaving the middle part with large plastic deformation,reduces it into a rectangle and anchors it with side frames,and connects it to the frame through four short sets of buckling restrained braces,forming a buckling restrained braces combination braced steel frame structure with replaceable shear plates.To further investigate the mechanical and seismic properties of the buckling-resistant composite braced steel frame structure with replaceable shear steel plates,5-bay 1/3 reduction specimens were designed and subjected to reciprocal loading tests,and a 30-bay analytical model was established using the finite element software ABAQUS,and the structure was numerically analyzed by one-way loading and reciprocal loading.The effect of parameters such as the cross-sectional dimensions of the frame columns,the width-to-thickness and aspect ratios of the shear steel plates,the angle between the buckling restrained braces and the horizontal plane,and whether the buckling restrained braces is equipped with contact rings on the loadcarrying capacity,stiffness degradation,ductility,and energy dissipation performance of the buckling restrained braces composite braced steel frame structure with replaceable shear steel plates were investigated.The following conclusions were obtained from the experimental study and finite element analysis:(1)Reciprocal loading tests were carried out on five bays of 1/3 shrinkage specimens to discuss the seismic performance of the structure.It is obtained from the tests that the buckling restrained braces can transfer the force to the shear steel plate well so that the shear steel plate forms a diagonal tension band with yielding energy dissipation,and the hysteresis loop of the structure is full with a high load-carrying capacity and good energy dissipation performance,which proves the feasibility of the buckling restrained braces steel frame structure with replaceable shear steel plate.(2)Through the reciprocal load test,it is found that the shear steel plate is the main deformation energy dissipation element of the structure,the easier the shear steel plate flexes,the greater the degradation of the stiffness of the structure,the better the energy dissipation performance,through the process of structural deformation can be seen,the shear steel plate first deformation,gradually forming the main diagonal tension band,then the buckling restrained braces yielding deformation,and finally the shear steel plate and buckling restrained braces damage leading to combined support The frame is intact during the whole deformation process.After the replacement of the shear plates and Buckling restrained braces,it was found that the load-carrying capacity,initial stiffness,and energy dissipation properties of the structure were not affected before and after the replacement.The replacement procedure was simple and time-consuming and proved that the replacement of the shear plates and buckling restrained braces after the earthquake was feasible.(3)The structure is loaded in one direction by numerical simulation.The load carrying capacity,initial stiffness and ductility of the structure are better when the shear steel plate widthto-thickness ratio and length-to-width ratio are within reasonable values.(4)structure under reciprocating load,shear steel plate width-thickness ratio and aspect ratio on the structure of energy dissipation performance has a greater impact,the greater the shear steel plate width-thickness ratio and aspect ratio,the better the structure of energy dissipation performance,and the shear steel plate width-thickness ratio and aspect ratio should be within a reasonable range;buckling restrained brace set contact ring structure of higher loadbearing capacity,buckling restrained braces and the horizontal plane of the angle closer to the main diagonal of the shear steel plate The closer the angle between the buckling restrained brace and the horizontal plane is to the main diagonal of the shear plate,the better the seismic performance of the structure.(5)By comparing and analyzing the experimental and finite element data,the experimental and finite element results are consistent in terms of both deformation and damage laws and seismic performance of the structure,and finally,the experimental and finite element analysis results of the buckling-proof composite braced steel frame with replaceable shear steel plates are reasonable and provide reliable recommendations for engineering design. |
PDF Full Text Request