Experimental study on thermal expansion and mechanical properties of high-strength steel wires and twisted wire strands at elevated temperatures
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 1 860 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 1 860 MPa steel wires and 1 860 MPa 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 1 860 MPa 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.
国家科技期刊平台
NSTL
万方数据
维普
