高强钢丝和钢绞线热膨胀和高温力学性能试验研究  

Experimental study on thermal expansion and mechanical properties of high-strength steel wires and twisted wire strands at elevated temperatures

作　　者：楼国彪[1,2] 侯婧 戚洪辉 宋战辉 李国强[1,2] LOU Guobiao;HOU Jing;QI Honghui;SONG Zhanhui;LI Guoqiang(College of Civil Engineering,Tongji University,Shanghai 200092,China;State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《建筑结构学报》2024年第4期198-205,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51578420)。

摘　　要：为获取高强钢丝和钢绞线的热膨胀变形数据以及高温力学性能指标,通过国产1860 MPa钢丝的热膨胀变形试验研究,得到温度20~800℃下高强钢丝的热膨胀应变,并与已有的钢丝、钢绞线和钢丝束试验结果对比,提出了热膨胀应变拟合公式。通过高温下稳态拉伸试验研究,得到了国产1860 MPa钢丝和1860 MPa钢绞线的破坏模式、应力-应变关系和高温力学性能指标,并与已有的钢绞线、钢丝束试验结果和欧洲抗火设计规范的建议值进行了对比。研究结果表明:高温下不同强度的钢绞线的弹性模量折减系数、断裂应变折减系数试验结果较离散,屈服强度折减系数、抗拉强度折减系数、极限应变折减系数试验结果较接近;在温度300~500℃时钢绞线的断裂应变远大于钢丝,在颈缩阶段的受力性能优于钢丝。欧洲规范中建议的应力-应变关系模型在颈缩阶段不适用于高强钢丝和钢绞线,为此,针对1860 MPa钢丝和钢绞线提出了高温下热膨胀系数和应力-应变关系模型,与试验结果吻合较好。To obtain the thermal expansion deformation data and mechanical properties of high strength steel wires and twisted wire strand at high temperature,based on thermal expansion deformation test on 1860 MPa steel wires at elevated temperatures,the thermal expansion strain at 20-800℃ was obtained and compared with that of other steel wires,twisted and parallel wire strands.The fitting formula of thermal expansion strain for high-strength cables was presented.Based on the static tensile test on 1860MPa steel wires and 1860MPa twisted wire strands at elevated temperatures,the failure mode,stress-strain relationship and mechanical properties were obtained and compared with the results from other tests and the specified provisions in the fire resistance design codes of Europe.The test results show that the reduction factors of the elastic modulus and fracture strain of different cables at elevated temperatures are disperse,and the reduction factors of yield strength,ultimate strength and ultimate strain are more consistent.The fracture strain of twisted wire strands is far greater than that of steel wires at 300-500℃,indicating better mechanical performance of the former at necking stage.The prediction of stress-strain relationship by EC 2 is inconsistent with that of steel wires and twisted wire strands at necking stage.For 1860MPa steel wires and twisted wire strands,the thermal expansion coefficient and stress-strain relationship model were presented in this paper,which agree well with the test results.

关 键 词：高强钢丝 钢绞线 高温 热膨胀 力学性能 

分 类 号：TU511.3[建筑科学—建筑技术科学] TU317.1