| With the wide application of high-rise and super-tall buildings,the structural form has gradually changed from frame structure to shear wall structure,frame-shear wall structure and tube structure,then the proportion of shear wall application has increased rapidly.Therefore,the research direction has gradually shifted from the study of frame performance to the performance study of shear walls.The design and simulation methods of traditional frame structures have formed a relatively mature system after years of research and accumulation,but the research work on the shear wall structure is relatively lagging compared to the frame structure.Especially when the non-linear dynamic response analysis becomes a necessary means of structural analysis,the shear performance and shear model of shear walls are particularly important.Although a certain number of shear wall tests have been gradually accumulated in the world,most of them do not involve the separation of bending and shear deformation,and the shear wall tests are mostly carried out with small shear span ratio,but few with large shear span ratio.From this point of view,the progress of the shear wall test is still relatively limited,which can not keep up with the development trend of structural analysis and calculation model.However,the largest gap in shear wall research is the definition of the shear model(shear-shear deformation(or shear angle)relationship)in nonlinear dynamic response analysis.Although some suggested models have been put forward by various countries,the existing models have not been tested by more experiments,and have not been widely accepted by academia and widely used by engineering circles.Therefore,the inelastic shear model of shear wall is a work worth studying.In this paper,the finite element method is used to study the inelastic shear spring material model of shear wall.Firstly,based on the experiments of reliable separation of bending and shearing deformation and two separation methods of shearing deformation,the finite element softwares based on different element models are used for simulation analysis and comparison verification.According to the comparison results,selecte the relatively reasonable finite element analysis and separation method of shearing deformation.Then,a large number of shear wall members with different parameters are simulated by the selected finite element software,and the shear deformation in the non-linear deformation is separated according to the selected shear deformation separation method.As a result,the shear-shear deformation relationship of each member can beobtained.On this basis,the effects and specific rules of each influencing factor on the fixed point(shear stress and shear angle)of shear material model is analyzed,and the function formulas of the fixed point(shear stress and shear angle)of the model are obtained by numerical regression fitting.Since our team has already done inelastic dynamic response analysis of the shear wall structure designed according to the shear model recommended by early foreign experts,the regression fitting shear material model is applied to the same structure and its dynamic response analysis is completed in this paper.It shows that the conclusions of damage degree of shear wall members obtained by the two simulation analysis are obviously different.This paper analyses and evaluates these differences,and proves that the shear material model fitted in this paper can more effectively judge the mechanical performance and damage degree of the wall members of shear wall structure.The main conclusions drawn from the above finite element analysis and research are as follows:? VecTor2 finite element software is determined as the finite element simulation software of this paper by its accurate simulation of shear wall member performance and shear deformation calculation data.? By comparing and evaluating the shear deformation separation methods of Alessandro test in Switzerland and Tran test in America,the definition of shear deformation in non-linear deformation of shear wall is defined as total deformation minus bending deformation.? VecTor2 finite element software is used to simulate shear wall members with different parameters and separate shear deformation to obtain shear-shear deformation relationship.Then,the effects and specific rules of the influence factors on the fixed point of the shear material model are analyzed.Finally,the shear force(shear stress)and shear angle at the fixed point are fitted numerically,and the definition formula of the shear material model suitable for PERFORM-3D non-linear software shear wall element is obtained:? By comparing the regression-fitted shear material model and the Sozen and Moehle proposed models cited by Liu Yang's paper,it is proved that the strength of the Sozen and Moehle proposed model is much higher,while the regression-fitted shear material model conforms to the actual shear capacity.In the actual structural example,the two shear material models cause great difference in the oblique section performance and inelastic energy dissipation of the shear wall,but have little effect on the overall response of the structure and the normal section performance of the shear wall.The paper has the following innovations:? In this paper,a new method for defining inelastic shear material model is proposed.Previously,it was defined on the basis of experimental data and theoretical research.Now,the model can be analyzed and defined more comprehensively and accurately by means of finite element method.? This paper collects the shear deformation separation test and separation method,and carries on the finite element verification and evaluation,which provides the theoretical basis and data support for the determination of shear deformation in the shear material model.? The shear material model obtained by the study is compared with the existing model and substituted into the structural example for analysis and verification,and its influence on the overall structural index and the response of the shear wall member are evaluated. |
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