弹性剪切连接组合梁的应力计算方法

A METHOD FOR CALCULATION OF STRESS OF COMPOSITE BEAMS WITH ELASTIC SHEAR CONNECTIONS

在桥梁结构中组合梁的弹性计算是一项重要的内容,然而要精确计算组合梁在弹性剪切连接(即有滑移)时的应力,须用到微分方程的解析解,在简单荷载作用下的静定结构还可得到这些解析解,但当荷载形式较复杂或为超静定结构时,要得到解析解就很困难了。目前还没有即简便、精度又高的实用计算方法,在《钢结构规范》[1](GB50017-2003)中也没有相关的内容可寻。为此,该文提出了一新的组合梁应力计算方法——有效刚度法,该法计算简便、力学概念清晰、计算精度高,能适用于任意荷载形式和任意大小的剪切连接刚度。计算结果中得到的组合系数还能非常直观地评价组合梁的组合作用大小,并可用于组合梁的有效抗弯刚度的计算。

The elastic analysis of composite beams is an important content in bridge engineering.However,an accurate calculation of stresses of composite beams with elastic shear connections（with slips） is quite inconvenient,because a closed solution is needed.Getting a closed solution is possible for simple loads and is very difficult for complicated loads or statically indeterminate beams.At present a simple and accurate calculation method is not available and a related content cannot be found in（national norm） ＂code for the design of steel structures＂.For this reason,a new method called ＂effective rigidity method＂ for calculating stresses of composite beams is proposed.The method is simple,accurate,with a clear mechanic bases and suitable for arbitrary loads and rigidity of shear connections.A composite factor obtained from calculation results shows how many composite effects are and can be also used to calculate flexural rigidity.