Application Of Softened Membrane Model In The Finite Element Analysis Of Low-Rise SRC Shear Walls

Low-rise steel reinforced concrete (SRC) shear wall is a type of compositesteel-concrete shear wall, which is formulated by adding extra shaped steel or steel platein traditional reinforced concrete (RC) shear wall. Because of its various advantages,such as high carrying capacity, excellent ductility, SRC shear wall has been widely usedin engineering practice. However, due to the complexity of its cross-section compositionand shear-dominated deformation, mechanical behavior of SRC shear wall is morecomplex than ordinary structure components. Insufficiency test data and constraints onperformance of finite element analysis put some limitations on the existing researchwork.Considering mechanical behavior characteristics of low-rise SRC shear walls, theauthor conducted a preliminary analysis on material constitutive model which is suitablefor analysis of low-rise SRC shear walls. On the basis of softened membrane model(SMM) presented by Thomas T. C. Hsu, the writer combined the orthotropic nonlinearconstitutive theory of concrete proposed by Darwin and Pecknold, developing AbaqusFEA-based user material subroutine. By linking user subroutine to Abaqus throughUMAT, The author carried out a series of FEM analysis on the plain concrete slabs,reinforced concrete shear panels, low-rise RC shear walls, as well as low-rise SRC shearwalls. Then the calculated results were compared with the experiment data, showingthat the user subroutine developed in this paper and modeling technic can simulateoverall mechanical performance of low-rise SRC shear wall well.In order to study specific behaviors of low-rise SRC shear walls, later on the authordesigned a low-rise SRC shear wall with axial compression ratio equaling to one, andconducted finite element analysis in Abaqus by using the simulation method developedpreviously. Four possible factors affecting the behavior of low-rise SRC shear wallswere studied, which are the steel ratio, distributed reinforcement ratio, bracing steelratio, and axial compression ratio.