铁路混凝土工程钢筋机械连接疲劳性能试验研究  

Research on Fatigue Test of Reinforcing Steel Mechanical Connection in Railway Concrete Engineering

作　　者：陈强 钟志强 李葳[3] 

机构地区：[1]蒙西华中铁路股份有限公司,北京100073 [2]安徽金星预应力工程技术有限公司,安徽合肥231135 [3]中国铁道科学研究院科学技术信息研究所,北京100081

出　　处：《中国铁路》2017年第3期59-67,共9页China Railway

基　　金：南广铁路公司科技研究开发计划项目(南广工合201107)

摘　　要：基于"等强度连接"设计原则,采用常用3种直径的钢筋,结合螺纹接触力学计算与加工难易程度,选定疲劳性能试验研究的连接件规格,并进行疲劳性能试验研究,得出如下结论:(1)除Φ32mm、P=3.0mm镦粗直螺纹连接接头的结果不满足100MPa应力幅、200万次疲劳循环试验外,其余连接件均能满足要求,且滚轧直螺纹连接组件的S-N曲线最为平缓,疲劳性能最好,挤压型连接形式次之,镦粗直螺纹连接形式效果最差;(2)从螺距上比较,2.5mm螺距的连接形式得出S-N曲线最为平缓,疲劳性能较好,2.0mm、3.0mm基本相当;(3)当采用所有的试验样本进行S-N曲线回归分析后,曲线的斜率为-0.20662,与欧洲规范规定斜率-0.2误差3.31%,连接件设计合理,工艺可靠;(4)疲劳断口多发生在连接件之外钢筋母材的第一圈螺纹处,与滚压、镦粗和挤压对钢筋母材的影响规律一致。实际应用时,可参考归一化分析的S-N曲线,选定合理的疲劳强度及疲劳寿命,确保结构的疲劳性能满足使用要求。Based on the design principle of ＇equal strength used diameters was adopted in this paper, combined with connection＇, reinforcing steel of three commonly the calculation of thread contact mechanics and difficulty of processing, the type of connecting piece used in fatigue test research was chosen, and the fatigue test research was carried out, coming to the following conclusions： （1） Except the D32-3.0 upsetting straight thread connector which fails to meet the requirement of fatigue cycle test under the condition of 100 MPa stress amplitude and 2 million times, all other connectors could meet the requirement, with rolled straight thread having the flattest fatigue S-N curve and the best fatigue performance. The extrusion connector comes the second, while upsetting straight thread connector has the worst performance; （2） By comparing screw pitch, the 2.5 mm pitch connection generates the flattest S-N curve and performs the best. The 2.0 mm and 3.0 mm take on almost the same performance; （3） By implementing the S-N curve regression analysis of all test samples, the slope of the curve turns out to be -0.206 62, which has a 3.31% deviation from -0.2% slope set out in the European standards. The connector has reasonable design and reliable techniques; （4） Most of the fatigue fractures occur at the first thread turn of reinforcing steel base metal, which is in compliance with the rule in terms of the influence exerted by rolled, upsetting and extrusion on reinforcing steel base metal. In practice, the S-N curve of normalized analysis could be referred to, in order to choose the suitable fatigue strength and fatigue life, and to ensure that the fatigue performance of structure could satisfy the operating requirements.

关 键 词：机械连接 疲劳性能 螺纹钢筋 粗钢筋 S-N曲线 等强度连接 

分 类 号：TU513[建筑科学—建筑技术科学]