弦支穹顶结构施工过程数值模拟及施工监测

Numerical simulation and in-situ monitoring of pre-stressing construction of suspen-dome structures

为解决弦支穹顶结构施工控制技术中撑杆下节点处的预应力滑移摩擦损失问题,考虑到滚动摩擦力远小于滑移摩擦力,提出一种含滚轴的滚动式撑杆下节点,并将其应用于某体育馆弦支穹顶结构。为验证滚动式撑杆下节点在降低预应力滑移摩擦损失方面的工作性能以及张拉施工过程中结构的安全性,采用ANSYS中的APDL语言编制了预应力施工数值模拟程序,对预应力张拉施工过程中索力、杆件内力和结构变形进行了全过程分析,同时对体育馆弦支穹顶结构预应力张拉过程进行了施工监测。结果表明:滚动式撑杆下节点的预应力摩擦损失在5%左右,是传统撑杆下节点预应力摩擦损失的50%;预应力张拉过程中,杆件轴向应力低于50 MPa,施工方案安全可行;施工监测数据验证了施工摩擦滑移数值模拟程序的可行性。

The pre-stressing loss induced by sliding friction is one of the most difficult construction techniques for suspen-dome structures,and no effective method is available now.Because the rolling friction is much smaller than the sliding friction,a new cable-strut joint,which includes a roller,was presented to reduce the friction between hoop cable and joints.This new joint has been adopted in the suspen-dome structures of Shandong Chiping Gymnasium.In order to verify the work performance of the new joint in reducing the pre-stressing frictional loss and the structural safety,a numerical procedure for the pre-stressing construction was written using APDL Language on ANSYS software.Using the numerical procedure,the cable force,the member stress and nodal displacement during pre-stressing construction was analyzed.Furthermore,an in-situ construction monitoring was also conducted.The analysis results and in-situ construction monitoring data show that the frictional pre-stressing loss of the new cable-strut joint is about 5%,which is 50% of the traditional cable-strut joint.The member axial stress is less than 50 MPa during pre-stressing construction,therefore,the construction scheme is feasible.The in-situ construction monitoring data has verified the feasibility of the numerical procedure.