预应力引起结构“次内力”的概念及计算

THE CONCEPT OF SUB-INTERNAL FORCE CAUSED BY PRESTRESSING FORCE

在后张预应力框架结构设计中 ,用“预应力等效转换”计算“次内力”的方法即按“位移法”的力学模型和约定方式是取一根两端固结的预应力杆件为基本单元 ,用结构力学的基本方法推导张拉反力作用下各种不同预应力筋形杆单元的“载常数” ,将预加力等效转换为作用在杆端的“固端约束力” ,从而计算出“次内力”。依据此理论编写了一个应用程序 ,来迅速而简便的计算“次内力”。该理论计算方法通过几个工程实例的验证 ,结果表明该方法是可行的 。

The calculation method for‘sub-internal force’in post tensioning frame work was introduced in details,and a new approach to evaluate the mechanics model:take both end-fixed member as basic unit,then observe the transfigure about it,when pulling it with a stressing force.So,the factor could be obtained to calculate the ‘sub-internal force’as transforming the pre-stressing force into restraining force.In this paper,a procedure is determined on the base of the theory for computing the ‘sub-force’quickly.The theory is proved to be useful and reliable in practice.