Study On Seismic Performance Of Wall In Bottom Reinforced Area Of Box-plate Steel Structure Residence

Box-and-plate steel structure residence is a new type of prefabricated structural system put forward by the research group.This structural system is derived from the ship's superstructure.When such structural system is applied to high-rise buildings,the stiffened steel wall at the bottom will bear a great deal of vertical and horizontal loads.In order to improve seismic performance such as load-carrying ductility and energy dissipation capacity of the bottom stiffened steel plate under earthquake,the research group proposed a new type of steel plate wall-composite steel plate shear wall based on the stiffened steel plate wall structure.It mainly studies the seismic performance of the newly proposed composite steel plate shear wall.The main contents and results are as follows:(1)A low-cycle repeated load test of a stiffened steel wall specimen and three composite steel wall specimens was completed.The main research parameters of the composite steel wall are the presence or absence of stiffeners and the bolt spacing of the precast concrete panels.Seismic performance indicators such as failure process,failure mode,bearing capacity,energy dissipation capacity,ductility,stiffness degradation,and load bearing degradation of the four specimens were examined.The study shows that the stiffened steel plate wall is sparse and large in size due to buckling under low cyclic loading,while the composite steel plate shear wall has tighter tension bands and smaller size.The composite steel plate shear wall has higher bearing capacity than the stiffened steel plate wall.The ductility is better,and the energy dissipation capacity is stronger;removing the L-shaped stiffeners of the composite steel sheet wall or increasing the bolt spacing will reduce the bearing capacity,energy dissipation capacity and deformation performance of the composite steel shear wall.(2)The finite element software ABAQUS was used to perform nonlinear finite element analysis on the test specimens.The comparison between the finite element results and the test results shows that the hysteretic curve,skeleton curve,and deformation agree well with each other,which verifies the effectiveness of the finite element modeling method.(3)The finite element software ABAQUS was used to analyze the seismic performance parameters of the combined steel plate wall.The parameters analyzed included: bolt arrangement,high-thickness ratio,rib plate stiffness ratio and axial compression ratio.The analysis results show.The greater the spacing between bolts,the lower the bearing capacity is,the more severe the hysteresis curve pinching,and the worse the energy dissipation capacity is;The greater the ratio of height to thickness,the lower the resistance to lateral stiffness and bearing capacity is,the more severe the hysteresis curve pinching,the worse the energy dissipation capacity is,and the slower the stiffness degradation rate is;When the rib stiffness ratio increases from 0 to 20,the bearing capacity and energy dissipation capacity are greatly improved,but the stiffness ratio of the ribs continues to increase,and the bearing capacity and energy consumption capacity increase is not obvious.The axial compression ratio has little effect on the hysteretic energy performance of the composite steel plate wall,but the larger the axial compression ratio,the smaller the bearing capacity is,the faster the bearing capacity declines at the later loading stage is,and the more severe the stiffness degradation is.Based on the test and finite element analysis results,when the bolt spacing is 220 mm,the precast concrete slab has an ideal out-of-plane restraint effect on the steel plate.Therefore,it is recommended that the bolt spacing of the composite steel plate wall be 220 mm.On this basis,the stress mechanism of the thick steel plate wall with a relatively small height and thick steel plate and the thick steel plate wall with a relatively high thickness is analyzed.The analysis shows that the steel plate occurs when the loadbearing force of the thick steel plate wall reaches the limit state.Shear yielding,thin steel plate wall shear buckling occurs when the bearing capacity reaches the limit state.According to the stress mechanism,a unified calculation model was proposed.Based on the computational model and a large number of finite element analysis data,a nonlinear fitting method was used to give a formula for the calculation of shear ultimate bearing capacity.