Experimental Study And Theoretical Analysis On Seismic Performance Of Composite Shear Wall With Steel Tubes And Filled Concrete

Composite shear wall with steel tubes and filled concrete is a shear wall with the combination of steel and concrete which acts as a main anti-vertical force and anti-lateral force component of the structural system.It is combined with U shaped steel with different sections,which are filled with concrete.The common forms of composite shear wall with steel tubes and filled concrete are one font,T type and L type.It possesses advantages such as thin steel pipe,economy of steel consumption,quick speed of construction,simplicity of fabrication,and light weight.It has broad applicability and economic social benefits.In this paper,through in-depth and systematic research,we conducted experiments and theoretical research on the composite steel plate shear wall with steel tubes and filled concrete,the main research contents are as follows:(1)Seven full-scale one-font type composite shear wall with steel tubes and filled concrete models that are totally consistent with the actual project are designed.The experimental study of the low cycle reversed load on the model is made,and several comparisons have been made considering different axial compression ratio,shear span ratio,U type steel section size,whether with studs or not;through the tests,failure mechanisms of the wall are revealed,and the impact of the various parameters on seismic performance of the composite shear wall failure pattern,hysteresis curves,skeleton curves,strength and stiffness degradation,ductility coefficient and energy dissipation capacity were analyzed.The shear deformation,lateral deformation,the strain of the key part of the wall,and the wall deformation mechanism have been analyzed.(2)Compared with one-font type composite shear wall with steel tubes and filled concrete,five 1:1 full-scale T type composite shear wall with steel tubes and filled concrete models that are fully consistent with the actual engineering are designed,and they were tested under low cyclic loading;several comparisons have been conducted considering different axial compression ratio,shear span ratio,U type steel plate section size,and whether with studs or not;through the tests,the failure mechanisms of the T type wall are revealed,and the impact of the various parameters on seismic performance of the T type composite shear wall failure pattern,hysteresis curves,skeleton curves,strength and stiffness degradation,ductility coefficient and energy dissipation capacity were analyzed.The shear deformation,lateral deformation,the strain of the key part of the wall,and the T type wall deformation mechanism have been analyzed.(3)The numerical simulation on composite steel plate shear wall with steel tubes and filled concrete was conducted with the nonlinear finite element software,and the theoretical analysis results were verified with test results.The stress and strain state and the failure mode of the shear force walls are researched.Thereafter,the parametric analysis has been conducted to study the influences of main factors,such as the axial compression ratio,shear span ratio,strength of steel,concrete strength,the thickness of the steel plate,U type steel section size on the seismic performances of the walls.(4)A simplified calculation model-trilinear model of the skeleton curve of the composite steel plate shear wall with steel tubes and filled concrete is obtained based on the low cycle reciprocating load test and corresponding study on hysteretic curve and restoring force characteristics.Moreover,stiffness degradation law of the shear wall was analyzed;and based on the experimental phenomena,the hysteretic rules are analyzed.Based on the trilinear model of the skeleton curve and the hysteretic rules,the restoring force model of the shear walls was established.(5)Based on the experimental data and the finite element parametric analysis,the main factors influencing the bearing capacity of composite shear wall with steel tubes and filled concrete are analyzed.Based on the superposition theory,the calculation formula of the bearing capacity of the shear walls was proposed.The components of the shear capacity was obtained on the base of the analysis of the force mechanisms of the low shear-span ratio of the wall as well as of main factors affecting shear capacity.Based on the superposition theory and statistical calculation of the parameters of the regression,the calculation formula for the shear capacity was developed.Finally,the recommendations on the seismic design of the walls were proposed.