组合梁挠度计算的改进折减刚度法

该文总结了部分抗剪连接组合梁挠度计算的不同方法，并通过对均布荷载作用下两端简支组合梁跨中挠度的对比分析，讨论了各种方法的特点。针对现行规范中采用的折减刚度法所存在的问题，进行了分析研究，提出了组合梁挠度计算的改进折减刚度法。理论分析和数值结果表明，改进的折减刚度法克服了规范中的折减刚度法所存在的抗剪连接程度增大，组合梁抗弯刚度反而减小导致挠度增大的矛盾，同时考虑了边界条件对折减刚度的影响，且与精确解相比，两者吻合较好。

MODIFIED REDUCED STIFFNESS METHOD FOR CALCULATING THE DEFLECTION OF COMPOSITE BEAMS

Some methods to calculate the deflection of composite beams with partial shear interaction were summarized, and the characteristics of these methods were discussed through the mid-span deflection of a simply supported beam acted by uniformly distributed load. The drawbacks of the reduced stiffness method (RSM) used in the current code for design steel structures were analyzed theoretically and a modified reduced-stiffness method (MRSM) for calculating the deflection of composite beams was proposed. Theoretical analysis and numerical examples show that the MRSM can overcome the drawbacks of the RSM, avoiding the conflict of bending stiffness of composite beams decreasing with the stiffness of the shear connectors. The MRSM can also take into account the influence of boundary conditions on the reduced stiffness and has a good agreement with the exact solution.