预应力组合梁结构试验研究与剪滞效应分析

Experimental Study and Analysis on Shear Lag Effect of Prestressed Composite Beam Structure

为了深入分析剪滞效应对预应力钢-混凝土组合梁结构的影响,提出了一种新型的宽翼缘双箱钢-混凝土组合梁结构并进行试验研究,探讨了该结构在跨中集中荷载作用下组合梁的应力、应变,及挠度随荷载变化的特征。基于最小势能原理,并假定翘曲位移形函数,建立控制微分方程组,推导出了考虑剪滞效应、预应力增量作用下的应变及挠度函数表达式。结合算例,在线弹性范围内,对该组合梁结构进行了剪滞效应对比分析,结果表明:其误差在15%以内。

In order to make an in-depth analysis on shear lag effect of prestressed steel-concrete composite beam structure,a new type of double-box steel-concrete composite beam with wide flange was proposed and researched through the test,and its load-stress curves,load-strain curves,and load-deflection curves were discussed under mid-span concentrated load. Based on the warping displacement model assumption,governing differential equations were established by the minimum potential energy principle,and expressions of strain and deflection were deduced considering both shear lag effect and prestressed increment. Finally,combining with the example,contrastive analyses on shear lag effect between test and theory were also launched within the elastic stage,analysis solution showed that the error within 15%.