Analysis On Mechanical Performance Of RUHPC Combined And Prefabricated Shear Wall

Shear wall structures have been widely used in buildings.With the development of buildings industrialization,assembled shear walls are an important direction for the development of shear wall structures.The RUHPC prefabricated composite joint shear wall structure is proposed as one kind of high degree of prefabrication structures.Lightweight and high-strength RUHPC non-removal shell form are used as the permanent Multi-Function formwork for the post-cast joint area.The flexural and shear bearing capacity of RUHPC assembled composite joint shear wall is studied in this paper.The parameters based on the softened truss model is analyzed.Firstly,a numerical model for calculating the tension stiffening effect of RUHPC is proposed.Based on this numerical model,the average stress of steel bar and UHPC during tensile stiffening is calculated,and the tensile constitutive of steel bar and UHPC considering tensile stiffening effect is proposed.The RUHPC unidirectional tensile test is designed and conducted based on the volume ratio of steel fiber and the reinforcement ratio.Test results show that when the reinforcement in the RUHPC uniaxial tensile specimen yields,the steel fibers in the UHPC material can still resist part of the tensile force.Comparing the calculation results of tensile constitutive with tension stiffening effect to the experiment,the effectiveness of tension constitutive is verified.Secondly,the RUHPC's tension constitutive considering the tension stiffening effect is applied to the softened truss model.Based on the literature test,the UHPC softening coefficient is fitted.Combining with the existing UHPC compressive constitutive,the UHPC compressive constitutive considering softening coefficient is proposed.Based on the above two points,a softened truss model suitable for RUHPC materials is established.The UMAT,user-defined material subprogram,based on the commercial finite element software ABAQUS is re-developed,and the softened truss model suitable for RUHPC materials is input into ABAQUS as the material constitutive calculation model.Based on the material constitutive,the finite element simulation of the RUHPC shear beam literature test is carried out and compared with the test results.It is proved that the RUHPC material softened truss model can effectively simulate the RUHPC shear specimen.Finally,the re-developed material constitutive is subjected to finite eleme nt simulation of concrete and RUHPC shear wall,and compared with literature tests,and it is proved that the finite element model can accurately describe the shear mechanical response of the shear wall.Based on the finite element model,the RUHPC composite joint shear wall is simulated.Based on the simulation results,the parameter analysis is carried out.The results show that the RUHPC composite joint plate can improve the bending shear capacity of the structure and increase the deform capacity of the structure.Based on the lower bound method of plastic limit analysis,the bending capacity formula of RUHPC composite joint shear wall is proposed,and the calculation method of shear capacity of RUHPC composite joint shear wall is proposed based on the softened strut-and-tie model.And based on the re-developed material constitutive,the finite element simulation of the bending capacity formula and the calculation method of the shear capacity were verified.