变截面筒中筒结构受扭分析

在开口薄壁杆件的扭转理论的基础上加以修正，推导出变截面筒体在扭转荷载作用下的扭角微分方程．提出筒中筒结构在纯扭矩作用下的力学简便分析方法，即利用连续化假定，分析了变截面处的边界条件，求出了在两种常用荷载(顶端集中扭矩、均布扭矩)作用下的协调传递矩阵．利用连续化条件求出任意截面的参数，然后推广到多个变截面求出任意楼层的扭转角及内力．该法适用于n阶变截面的筒中筒结构的受扭计算分析，并适用于计算机计算，思路清晰，计算量小，简便易掌握，是一种合理适用的简便计算方法．

Analysis of tube-in-tube structure of variable cross-section in torsion

On the foundation of the torsion theory of open thin-mural-beam,the torsion-angle differential equation of variable cross-section tube under torsion load is revised and deduced.A simple and convenient analysis method of tube-in-tube structure under pure torsion load is put forward.On continuum assumption,the method analyzes the boundary condition of variable cross-section and gets the coordinative transmit matrix under two common loads,top concentration torque and distributed equally torque.Parameters of any cross-section are counted on continuum condition.Popularized to several variable cross-section,the torsion-angle and internal force of any building layers are calculated.The method can apply to torsion calcuation analysis of n-step variable cross-section tube-in-tube structure,and to computer calculation.