框筒结构考虑负剪力滞效应的简化分析

Simple analysis of nagative shear lag efffect in frame-tube structures

在引入D值法分析框筒结构在水平荷载作用下的整体剪切变形和内力的基础上,提出了框筒结构各层同时存在正剪力滞和负剪力滞的简化假定,并假设了框筒各柱的轴向应变分布模式,对负剪力滞的影响因素进行了分析,得出了一些重要的结论。本文方法比等效平面框架法和等效连续体法更为简单、实用,可直接进行手算。通过与空间框架分析程序的比较,精度可供初步设计使用。

On the base of introducing the amendatory contra-flexure point method to analyze the whole shear deformations and forces of frame-tube structures, a simple assumption is put forward that positive and negative shear lag all exist in each storey of frame-tube structures under lateral loads. The assumed distributions of axial strains are given in the web and flange panels, in which the influencing factors of negative shear lag are discussed. Some important conclusions are obtained. The proposed method is much briefer and more applicable than equivalent plane frame method and equivalent continuous system method. Contrasting with space-frame analysis programs, the accuracy of the proposed method is demonstrated through the analysis of framed-tube structures. This method is a simple hand-calculation method and can be used for preliminary design.