索托结构中拉索预应力水平的优化研究  

An optimized pre-stress level for the design of cable supported trusses

作　　者：杨维国[1] 邹清[1] 李兴坡[1] 王耀峰[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《中国矿业大学学报》2012年第2期219-224,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(50808011;51178041)

摘　　要：为研究预应力对索托桁架体系内力和挠度的影响,引入预应力水平概念,对单榀索托桁架结构进行了有限元分析.通过自由度耦合和变刚度弹簧单元来模拟索托节点,考虑预应力摩擦损失对结构性能的影响,对不同预应力水平情况下结构体系的受力性能进行分析.探讨了不同预应力水平下,结构体系变形和构件内力的变化规律,并给出预应力水平控制的参考建议.研究结果表明:采用自由度耦合和变刚度弹簧单元来模拟索托滑移节点的方法收敛性好,能够满足工程计算精度的要求.索的预应力水平在0.4到0.6之间可对桁架挠度和杆件内力起到有效的控制作用,使桁架与柔性拉索协同工作.Finite element m^thods were used to analyze a cable supported truss. The influence of pre-stress on the internal forces and deflections of the cable supported truss were estimated by numerical simulation. Freedom coupling, variable stiffness spring elements were used to predict the mechanical performance of the truss at different levels of stress. Pre-stress friction losses were considered in the calculations. Variation in internal forces and deflections for differ- ent pre-stress levels are discussed and pre-stress levels suitable for construction are proposed. The simulations are convergent and meet requirements for engineering accuracy. A reasonable pre-stress level is between 0.4 and 0.6. This leads to reduced truss deflection and reduced in- ternal forces and optimizes the truss and cable design.

关 键 词：索托结构 桁架 预应力水平 内力 挠度 

分 类 号：TU394[建筑科学—结构工程]