负弯矩作用下考虑滑移效应的组合梁承载力分析

钢梁与混凝土之间的滑移效应对组合梁在弹性阶段的性能有很大影响。基于组合梁在负弯矩作用下的滑移微分方程,求出了连续组合梁负弯矩区的滑移及滑移应变解。根据滑移应变解,分析了组合梁在负弯矩作用下的截面应变分布,建立了考虑滑移效应的组合梁弹性承载力计算方法。计算表明,滑移效应导致组合梁截面曲率增大和钢筋应变滞后,在一定程度上减小了构件的弹性抗弯承载力,需要在设计和使用中予以重视。

EFFECTS OF SLIPS ON LOAD-CARRYING CAPACITY OF COMPOSITE BEAMS UNDER NEGATIVE BENDING

Slips at the interface of steel girders and concrete slabs have significant effects on the mechanical behavior of composite beams in elastic stage. Based on the differential equations of slips, the solutions of slip and slip strain in negative bending regions of continuous composite beams are obtained. By means of the slip strain solutions, the strain distribution of composite sections under negative bending is analyzed, and the methods for calculating the load-carrying capacity of composite beams are proposed. It is shown that the additional curvature induced by slip effect decreases the elastic moment strength of composite beams under negative bending moment in most conditions. This partial interaction effect should be considered in design.