超静定结构预应力等效结点荷载的计算

Calculation of Equivalent Nodal Load due to Prestressing in Statically Indeterminate Structure

本文基于结构分析的位移法，提出通过直接计算等效结点荷载的方法来计算预应力对超静定结构所产生的次内力。根据虚功原理引入杆件的形函数，推导了计算具有任意预应力筋曲线形状及沿预应力筋纵向具有任意分布的预应力所产生的杆端等效结点荷载的积分表达式。文东的算例表明该方法力学概念清晰，计算过程简单，可为预应力砼起静定结构的设计提供简单有效的工具。

Based on the displacement method of structural analysis, a method for computing the secondary internal force due to prestressing in statically indeterminate structure by direct calculation of the equivalent nodal load has been suggested.According to the principle of virtual work, a formula for calculating the equivalent nodal load due to prestressing with any initial shape of prestressing cable and any distribution of prestress along.the cable has been developed by using the shape function of a unit of structural element.Finally, an example of calculating the secondary moment due to prestressing in a two-span continuous beam shows that this formula can provide a simple and effective means for the design of statically indeterminate prestressed concrete structure.s because of its clear concept in mechanics and simple calculating procedure.