板梁系斜桥的内力分析

板梁系是桥梁中常用的结构形式。本文根据板梁系的比拟板理论,用三次B样条函数之积来逼近挠曲面,在正交坐标系下,写出正交异性板的总势能。通过正交坐标系和斜交坐标系之间的变换,导出斜交坐标系下的总势能。然后再应用变分原理,在文献的基础上,利用现有的表格形成斜板单元的刚度方程。和通常有限元相比,本法具有计算量少,节省机时、提高精度等特点。 根据本文的刚度方程,编制了FORTRAN计算程序,在IBM微机上即可运行。计算成果与文献中的实例相当符合。由于本文采用了比拟板理论,所以不论板梁结构纵横梁的数目有多少,都可以用该程序计算。因此,该程序在实际使用上是很方便的,具有一定的通用性。

ANALYSIS OF INTERNAL FORCES OF PLATE-GIRDER SYSTEM BRIDGES

Plate-girder system is a common structure used in bridges. In terms of the theory which consider the plate-girder system as a plate, the displacement model is approximated by double cubic B sample series. In orthogonal coordinates system, total potential energy is written out. Total potential energy in oblique coordinates is expressed through the transformation of orthogonl coordinates and oblique coordinates system. And then, Stiffness equation of oblique plate element is derived by using the variation principle and the list included in paper (1). In comparison with the traditional finite element, this method has the traditional finite element, this method has the advantages of less calculation and less time of computer calculating and higher precision. Giving a FORTRAN Programm to the equation, the ealculatiug result accord with practical example. This porgramm is suitable to no matter how many the beams are. Therefore, It is Convenient and Commonly to be used.