关键词: 弦支穹顶, 预应力损失, 摩擦因数, 网壳

Abstract: When tension cable is used to apply prestress to the suspended-dome structure, the determination of prestress loss value caused by sliding friction at the cabl-strut joint is one of the important contents in the structure forming theory. In this paper, the suspended-dome of Hebei North University gymnasium is taken as the research object. Based on the improved friction loss algorithm of freezing temperature cable, five calculation models of friction coefficient of cable-strut joints are established, which are 0.03, 0.1, 0.2, 0.3 and 0.4. The influence of sliding friction of cable-strut joints on internal force and deformation of cable-strut dome structure is explored. The results show that: in the whole process of tension,- DOI:10.3969/j.issn.1000-1565.2020.06.002弦支穹顶结构预应力张拉摩擦损失影响分析郄禄文¹,徐辰昱¹,刘静¹,赵若旭¹,陈宗学²( 1.河北大学 建筑工程学院,河北 保定 071002;2.河北建设集团股份有限公司 钢结构分公司,河北 保定 071052)摘 要:弦支穹顶结构采用张拉环索方式施加预应力时,在索撑节点处因滑移摩擦产生预应力损失值大小的确定是结构成形理论中重要内容之一.以河北北方学院体育馆弦支穹顶屋盖为研究对象,基于改进的冷冻升温环索预应力摩擦损失算法,建立索撑节点摩擦因数为0.03、0.1、0.2、0.3、0.4的5种计算模型,探究索撑节点滑移摩擦大小对弦支穹顶结构内力及变形等参数的影响.研究结果表明:弦支穹顶结构张拉全过程中,取5种不同摩擦因数时各圈环索预应力变化趋势基本一致;结构第1~2两内圈环索因相邻索段间夹角较小使得索撑节点处滑移摩擦力增加,导致索撑节点平均预应力损失分别高达20.50%、15.19%,此值均大于取相同摩擦因数时的3~5圈环索;下部索撑体系的撑杆和拉杆最大应力随摩擦因数增加均逐渐增大且皆出现在屋盖短轴两端;索撑节点摩擦因数取值大小不影响上部网壳竖向位移分布规律,且对网壳下凹和上凸最大位移值影响很小;上部网壳采用类圆角矩形拓扑结构导致网壳节点竖向位移在张拉过程中,位于第3圈环索以内沿环向和径向上凸且呈均匀对称发展,周边支座至第3圈环索区域的网壳节点位移由长、短轴两端上凸向45°方向逐渐凹陷.关键词:弦支穹顶;预应力损失;摩擦因数;网壳中图分类号:TU984.2 文献标志码:A 文章编号:1000-1565(2020)06-0569-09Effects of the prestressed tension friction loss for the suspended dome structureQIE Luwen¹, XU Chenyu¹, LIU Jing¹, ZHAO Ruoxu¹, CHEN Zongxue²(1. College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China;2. Steel Structure Branch, Hebei Construction Group Corporation Limited, Baoding 071052, China)Abstract: When tension cable is used to apply prestress to the suspended-dome structure, the determination of prestress loss value caused by sliding friction at the cabl-strut joint is one of the important contents in the structure forming theory. In this paper, the suspended-dome of Hebei North University gymnasium is taken as the research object. Based on the improved friction loss algorithm of freezing temperature cable, five calculation models of friction coefficient of cable-strut joints are established, which are 0.03, 0.1, 0.2, 0.3 and 0.4. The influence of sliding friction of cable-strut joints on internal force and deformation of cable-strut dome structure is explored. The results show that: in the whole process of tension,- 收稿日期:2019-12-27 基金项目:河北省自然科学基金资助项目(E2017201158);河北省高等学校科学技术研究项目(QN2016171);2016年“一省一校”专项经费资助项目 第一作者:郄禄文(1966—),男,河北阜平人,河北大学教授,博士,主要从事结构可靠度理论分析研究. E-mail:qieluwen@hbu.edu.cn 通信作者:刘静(1981—),女,内蒙古赤峰人,蒙古族,河北大学讲师,博士,主要从事钢结构与空间结构研究. E-mail:cimeng2005@163.com第6期郄禄文等:弦支穹顶结构预应力张拉摩擦损失影响分析when five different friction coefficients are taken, the change trend of the prestressing force of each ring of cable is basically the same. The angle of adjacent cable located on the first and second rings of the structure is smaller, which results in the average prestress loss of the cable-strut joints as high as 20.50% and 15.19%, respectively, which is greater than 3~5 rings of the same friction coefficient; with the increasing of friction coefficient, the maximum stress of struts and tention members in the lower cable support system increases gradually and appears at both ends of the roofs short shaft; the value of friction coefficient of cable-strut joint does not affect the vertical displacement distribution of the upper shell, and has little influence on the maximum displacement of the concave and convex of the shell. In the process of tension, the topological structure of rectangle like fillet is adopted in the upper shell, which causes the vertical displacement of the grid shell node located in the third ring of the cable, runs convexly along the ring and radial direction, and develops in a uniform and symmetrical way. The displacement of the grid shell node from the peripheral support to the third ring of the cable area run gradually concavely from the long axis and the short axis to the 45° direction.

Key words: suspended-dome, prestress loss, friction coefficient, latticed shell