分段降刚度法——混凝土杆系结构的一种简化试验分析方法

针对预应力混凝土和钢筋混凝土超静定杆系结构试验中进入非弹性状态后的结构内力难以准确测定的事实,本文提出了一种用于试验结构内力分析的简化方法--分段降刚度法.该方法根据试验中观测到的各杆件区段的受力状态,将各杆件依其刚度退化程度分为有限区段,并设定各区段刚度退化相对水准;再以试验中准确测得的关键变形量为校准点,经多次调试找到能给出该关键变形量的各杆件刚度降低系数;并认为用各杆件区段降低后的刚度经弹性分析求得的内力能反映试验结构的真实内力.经与一榀两跨单层大尺寸预应力框架考虑内力重分布的试验结果对比,初步证明本文所提方法有效.

A Simple Experimental Analysis Method for Reinforced Concrete Bar System Structures - Sectioned Dropping Rigidity Method

In order to solve the problem that the internal force of statically indeterminate prestressed and reinforced concrete bar system structures is difficut to determine when the structures come to the non-elastic state, a simple analysis method of experimental structures' internal force-sectioned dropping rigidity method is brought forward.In this method, according to the loading state of bars, the bars are divided into limited segments by the level of rigidity dropping, and the relative level of each segment is enacted; then the dropping modulus of each segment rigidity will be found by debugging time after time, and the checking point is the key distortion which was gained from the experiment; it is considered that the internal force which is calculated by elasticity analysis at the dropped rigidity can reflect the real internal force of the structures.It is basically proved that the method, which is brought forward in this paper, is effective by comparing its results with those from the experiment of a large size prestressed frame of two spans and single floor, of which the internal force redistribution is considered.