水平荷载作用下考虑扭转效应的交错桁架内力和位移计算

Calculation of internal forces and drift of staggered truss under lateral loads considering torsion

通过对交错桁架在水平荷载作用下受力特点和水平荷载传递途径的研究,在楼板刚度无穷大假定的基础上,提出了水平荷载作用下考虑扭转效应的桁架内力和楼层位移简化计算方法,给出了层分析模型的质量中心、刚度中心、计算偏心距的计算公式,考虑弦杆—楼板组合梁效应的桁架侧移刚度计算公式。结合算例,对简化方法与有限单元法的计算结果做了对比。其结果表明,两者相差不足5%。

The simplified calculating methods of internal forces and drift of staggered truss under lateral loads considering structural torsion is studied in detail based on the assumption that the stiffness of floor is infinite in plane. Not only the calculating formulas of the center of mass and rigidity of staggered truss story model, but also the calculating formulas of the eccentricity, the lateral stiffness of the typical truss considering, the compositing effect between the chord member and the floor are shown in the paper. A numerical example shows that the results obtained by the simplified method in the paper arc adjacent to the analysis results of the finite-element program, and the results include the lateral stiffness of the typical truss, the web member axial force and the drift of staggered truss.