Finite Element Analysis Of Mechanical Behavior Of Assembled Double Steel Casing Concrete Composite Shear Wall

In the process of urbanization in China,the combination of prefabricated buildings and high-rise buildings has become a development trend,and concrete-filled steel tubes are increasingly used in high-rise buildings because of their excellent mechanical performance.A new type of prefabricated double steel casing concrete composite shear wall was put forward and tested.The composite shear wall has the advantages of high bearing capacity and good ductility of concrete filled steel tube,convenience in assembling and less construction difficulty.Subject to the test conditions,there is still much work to be done in the research of this composite shear wall.In order to further study the mechanical behavior of this new composite shear wall and make it applicable in practical engineering,this thesis uses ABAQUS finite element software to fit and analyze this composite shear wall based on the existing test data,and the work carried out is as follows:1)according to the actual test data,a constitutive relation model conforming to the working conditions of concrete and steel in the actual test is established;2)A shear wall model with parameters based on test is established and subjected to cyclic loading.By comparing the test results with the finite element results,in terms of mechanical performance indexes such as bearing capacity,displacement ductility and crack development,the finite element simulation value has a good fitting degree with the test value,and the error is within an acceptable range.Then verify the rationality of the finite element model and reverse verify the accuracy of the test results;3)Based on the verified finite element model,a full-scale composite shear wall model is established.Based on the principle of single variable,the composite shear wall model of control group is established,which includes five parameters: round steel ratio,axial compression ratio,shear span ratio,section type and distribution reinforcement ratio.The effects of different parameters on the mechanical properties and failure modes of composite shear walls are compared and analyzed,and the mechanical mechanism of composite shear walls is revealed and relevant design suggestions are put forward.The results show that with the increase of round steel ratio,the bearing capacity of composite shear wall increases linearly,and the ductility increases first and then decreases.There is an optimal range of ductility when the round steel ratio is 5.4%～7.2%.The bearing capacity of composite shear wall increases slightly with the increase of axial compression ratio,but the increase amplitude decreases with the increase of axial compression ratio The bearing capacity of composite shear wall with small shear span ratio is higher,and the failure form tends to shear failure,while the failure form of composite shear wall with large shear span ratio tends to bend and shear failure Setting end columns at both ends of composite shear wall can effectively improve the bearing capacity of composite shear wall;Increasing the reinforcement ratio of distribution bars can improve the ductility of composite shear walls and inhibit the development of cracks.4)Based on the finite element simulation data,the existing related shear capacity formulas are adjusted,and the formula conforming to the shear capacity of composite shear wall is established,which verifies the rationality of the adjustment of related coefficients,and gives the formula of shear capacity of composite shear wall which can be applied to practical engineering and has certain security consideration.