预应力混凝土结构次内力计算方法

The calculating methods of secondary forces in PRC structures

预应力混凝土超静定结构中预应力作用会产生次内力,次内力的产生、计算同主内力有明显的不同,尤其是计算一直是教学与工程实践中的一个难点。本文阐述了次内力计算的基本概念,从计算方法、基本原理、计算路线和适用范围等四个方面比较了常见的预应力计算方法,同时对杆系有限元法计算次内力进行了初步分析,并总结了一些教学体会。最后笔者通过一个简单的力学算例,对几种方法的计算结果进行了比较分析。

In statically indeterminate structures of prestressed concrete, prestress will cause secondary forces. It is difficult for teachers and engineers to calculate the secondary forces because causing and the calculation of the secondary forces are apparently different from that of the primary forces. The basal concept of the secondary forces are illuminated, and the usual calculating methods of calculating technique, principle, computational path and extent are compared. At the same time, the secondary forces calculated by the finite element method are analyzed primarily,and the teaching experiences are summarized.Finally,the differences among these results using several methods are compared by a simple example.