Abstract: The variable cross-section beam is widely used in bridge engineering. C++ Language was used to write a program for calculating variable cross-section beam according to the actual change rule of section, and the result was compared with that of several other softwares. The result shows that the central axis is selected as coordinate can get higher precision than other position. But in order to model conveniently, the coordinate selected in bridge deck is also an effective method.

Key words: variable cross-section beam, beam element, stiffness matrix

摘要： 针对桥梁工程中广泛应用的变截面梁，按照截面的实际变化规律，采用C++语言编写了一种考虑节点位置在截面上可变化的变截面梁单元计算程序，计算结果与多种软件进行了比较。结果表明：对变截面梁进行结构分析时，坐标选取在形心轴较其他位置能得到更高精度的结果，但是为了建模方便，将坐标选取在桥面也是行之有效的方法。

关键词: 变截面梁, 梁单元, 刚度矩阵