Mechanical Behavior Analysis Of Unbonded Prestressed Tendon Precast Shear Walls With Energy Dissipation Angle Steel

The unbonded prestressed prefabricated shear wall structure(UPT)exerts prestressing force at the joints of the prefabricated wall board horizontal seams,so that the prefabricated walls have the ability of self-center under load.Research at home and abroad shows that its ductility and energy dissipation capacity under seismic load still needs improvement.The paper presents an improved connection detail for traditional unbonded prestressed tendon(UPT)prefabricated walls by placing the energy dissipation angle steel at the toe of the wall to improve the seismic performance of the wall,such as bearing capacity and energy dissipation capacity.The main research contents are as follows:(1)The finite element package MSC.Marc was used to model the UPT precast wall with angel steel.The finite element model was verified by a series of existing test data on UPT walls and angle steel,which demonstrated the rationality and accuracy of the modeling parameters concerning contact,unbounded prestressed tendon and constitutive model of the angel steel.Then parameter analyses were conducted to study the influence of the angle steel of size,tension control stress,axial compression ratio,prestressed tendons position and wall height on the lateral bearing capacity and ductility of the UPT walls with angle steel.(2)The simplified numerical calculation model of UPT wall with angle steel is put forward based on the simplified numerical calculation model of UPT wall,deducing the simplified calculation formulas for bending resistance ability,energy dissipation capacity and self-centering ability of UPT walls with angle steel,integrating wall sectional dimension(wall thickness B,wall width D),the total stress of the initial tension control of the prestressed tendons(Tp0),tensile yield force of energy-consuming angle steel(Tayx),the axis pressure of wall(N),and presenting new dimensionless parameters ?f(=Tayx/Tp0),?(=N/((BDfc))and qp(=Tp0(BDfc)),and then treating the numerical calculation model with dimensionless method under new dimensionless parameters.(3)On the strength of the simplified numerical model,the value range of?f(=Tayx/Tp0)is discussed under different value range of ?(=N/(BDfc)),qp(=Tp0/(BDfc).After determining the value range of the dimensionless parameters Pf(=Tayx/Tp0),?(=N/(BDfc))and qp(=Tp0/(BDfc)),the paper mainly studies the influence of each dimensionless parameter on the carrying capacity and energy dissipation capacity of UPT wall with angle steel.