Study On The Axial Compressive Behavior Of Corroded Double-steel-plate Composite Shear Wall With Binding Bars

The double-steel-plate composite shear wall(DSCW)has high load-bearing capacity,high deformation capacity,and superior seismic performance.However,steel structures are susceptible to corrosion.Corrosion can seriously affect its load-bearing capacity and service life,causing potential safety hazards and economic losses,limiting its engineering application.Taking the above into account,in this paper,the axial compressive bearing capacity of a common form double-steel-plate composite shear wall connected by binding bars under the influence of corrosion is investigated by experiment and finite-element simulation.The specific studies are as follows:(1)Three identical DSCW specimens were designed and fabricated for the accelerated corrosion test.By controlling the length of the voltaic time,specimens with different degrees of corrosion were obtained and the corresponding corrosion rates were measured.Then,the axial compressive loading test was conducted to investigate the influence of corrosion on the failure modes and axial compression performance of DSCW.(2)The typical failure modes of the DSCW specimens,which are characterized by the local buckling of steel plate,the tension fracture of binding bars,and the crushing of concrete,were shown in the experimental results.Corrosion can significantly reduce the initial stiffness,axial compressive bearing capacity,and ductility.The failure modes of DCSWs with different corrosion degrees showed no substantial difference.But due to the existence of residual welding stress,serious corrosion can cause a large area of local buckling and severe weld tearing of specimen steel plate.(3)Based on the design methodology of the experiment,the models of DSCW with binding bars were developed using the non-linear finite element software ABAQUS.By comparing the failure modes and the load-vertical displacement curves between test and simulation results,the reliability and the accuracy of finite element model were validated.(4)The influence of different parameters on the axial compressive bearing capacity,initial stiffness,and ductility of DSCW with binding bars were studied by applying the validated finite element model.The results showed that the corrosion rate,the concrete section area,the steel plate thickness,the steel plate strength grade,the concrete strength grade,the binding bars spacing,and the binding bars diameter all had a significant effect on the axial compressive bearing capacity.Increasing the concrete section area,reducing the height-to-width ratio,increasing the steel plate thickness and the concrete strength grade can all improve the initial stiffness of DSCW to a certain extent.Increasing the concrete strength grade,increasing the height-to-width ratio and the diameter and spacing of binding bars can all improve the ductility of the DSCW,with the height-to-width ratio having the most significant effect on the ductility of the DSCW.(5)Comprehensively considering the results of parametric studies and relevant national and international calculation specifications,based on the unified theory of steel and concrete,the formula for the axial compressive bearing capacity of DSCW with binding bars is established.And by considering the relationship between the corrosion rate and the axial compressive bearing capacity,a formula for the degradation of the axial compressive bearing capacity of corroded DSCW with binding bars is derived by adopting the data fitting method.(6)Based on the initial stiffness calculation formula of the DSCW in the code and the test results of this paper,the initial stiffness calculation formula for the DSCW considering the effect of corrosion is proposed.