位移控制预应力影响矩阵在弦支穹顶找力分析中的研究与应用  

Research and application of displacement control prestressed influence matrix in force-finding analysis of suspendome structure

作　　者：朱岩 尚仁杰[2] ZHU Yan;SHANG Renjie(China Nuclear Power Engineering Co.,Ltd.,Beijing 100840,China;Central Research Institute of Building and Construction Co.,Ltd,MCC Group,Beijing 100088,China)

机构地区：[1]中国核电工程有限公司,北京100840 [2]中冶建筑研究总院有限公司,北京100088

出　　处：《建筑结构学报》2021年第S01期195-202,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51578557)

摘　　要：弦支穹顶结构由上弦网壳、下弦拉索和撑杆组成,拉索预应力对结构内力和初始形态影响较大,合理确定预应力大小是弦支穹顶结构设计的关键。为此,根据线性叠加原理,将结构受力分解为外荷载作用与拉索预应力作用的线性叠加,提出了基于初应变和位移控制的预应力影响矩阵法。该方法通过依次计算单根环向拉索单位初应变下控制点位移值,形成位移控制预应力影响矩阵,计算竖向荷载下控制点位移值,建立相应的控制方程,求解控制方程得到各圈环向索对应的初始应变。弦支穹顶结构在所得初应变和外荷载下的索力就是在该荷载下的预应力值。结合某工程的深化设计,利用基于初应变和位移控制的预应力影响矩阵法对该工程实例进行了分析计算。结果表明,利用该方法计算出的初应变,可以保证竖向荷载下控制点的位移值小于2 mm,该计算方法物理意义较明确,计算较简便,准确度较高,可为类似工程的找力分析提供参考。Suspendome structure is composed of top chordreticulated shell,bottom chordcables and struts.Cable prestress has great influence on internal force and initial form of structure.It is the key to determine the prestress values for suspendome structure design.In this paper,according to the principle of linear superposition,structural force was decomposed into external load action and cable prestress action.A prestressed influence matrix method based on initial strain and displacement control was proposed.The method aimed to form the displacement control prestressed influence matrix through calculation of displacement values of control points under unit initial strain of a single loop cable.The displacement of control points under vertical load was calculated to establish the corresponding control equations.The corresponding initial strain of each loop cable was obtained by solving the equations.The cable tensions under initial strains and external load were the prestress values.Through the detailed design,prestressed influence matrix method based on initial strain and displacement control was verified.The result shows that using initial strain calculated by this method,the control displacement values of control points under vertical load can be controlled to be less than 2 mm.This method is not only clearly defined but also simple and accurate.It offers references for similar engineering in cable tension control.

关 键 词：弦支穹顶结构 预应力影响矩阵 位移控制 找力分析 初应变 

分 类 号：TU399[建筑科学—结构工程]