高温下及负载高温后1770级钢绞线力学性能研究OA

In this study,the mechanical properties of 1770-grade steel strands at elevated temperature and after thermal exposure are systematically studied.The reduction coefficient and its fitting formula of the mechanical properties of steel strands under the two conditions are proposed.The tensile properties of steel strands in the temperature range of 20 to 600℃were tested by a non-contact XTDIC three-dimensional strain measurement system,and the variation rules of mechanical parameters such as yield strength,ultimate strength,elastic modulus,and strain were analyzed.The test results show that the mechanical properties of the steel strand change slightly and exhibit brittle failure at temperatures of 200℃and below.When the temperature reaches 300℃and above,the mechanical properties deteriorate significantly,and the plastic deformation increases gradually.At 600℃,the yield strength and ultimate strength are reduced to 9%of the normal temperature,and the elastic modulus is reduced to 10%.The steel strand almost completely loses its bearing capacity.Besides,the mechanical properties of steel strands after high-temperature loading are significantly affected by the initial stress level.Especially after the temperature reaches 400℃and above,the greater the initial stress of steel strands,the more obvious the degradation of mechanical properties.