短肢PEC组合剪力墙的数值模型及公式拟合

Numerical Model and Formula for Short-Limb PEC Composite Shear Walls

PEC组合剪力墙是一种新型装配式剪力墙,具有承载力高、延性好、构造简单等优点。首先,基于纤维模型、部分约束混凝土及钢材的精确本构关系,研究了短肢PEC组合剪力墙弯曲变形及剪切变形的计算方法,在此基础上编制了短肢PEC组合剪力墙荷载-位移曲线的数值计算程序,并通过与已有试验及有限元分析结果的对比验证了该程序的准确性。然后,基于该程序对6480个不同截面参数的剪力墙进行了数值计算,分析了轴压比、剪跨比、含钢率、材料强度等关键参数对PEC组合剪力墙等效抗弯刚度和极限位移角的影响,拟合了短肢PEC组合剪力墙等效抗弯刚度及极限位移角的计算公式。对拟合公式的统计分析表明,等效抗弯刚度和极限位移角的计算公式满足精度要求,可用于指导短肢PEC组合剪力墙的设计。最后,基于规范对剪力墙结构弹塑性位移角限值的规定,提出了短肢PEC组合剪力墙轴压比限值的计算公式。

PEC composite shear wall is a new type of assembly-type shear wall,with high bearing capacity,good ductility,simple construction and other advantages.Based on fiber section analysis method and exact constitutive relationship of confined concrete and steel,a calculation method for bending deformation and shear deformation of short-limb PEC composite shear walls is presented.Then,a numerical calculation program of load-displacement relation of short-limb PEC composite shear walls is developed and the accuracy of the program is verified in comparison with experimental and finite element analysis results.On the basis of the program,6480 shear walls with different cross-section parameters are numerically calculated,and the effects of axial compression ratio,shear span ratio,steel ratio and material strength on equivalent bending stiffness and ultimate story drift of short-limb PEC composite shear walls are analyzed.Further,calculation formulas of equivalent bending stiffness and ultimate story drift of short-limb PEC composite shear walls are fitted.Through regression analysis of the fitting formulas,it is shown that the formulas meet computational accuracy and can be used to guide the design of short-limb PEC composite shear walls.In addition,a formula of allowable axial compression ratio of short-limb PEC composite shear walls is proposed,considering the limits of elastic-plastic story drift in specifications.