Research On Creep Property Of Wire Rope At Room Temperature

Steel cables are widely used in cable strut tension structures,cable-stayed bridges and suspension bridges.For the cable strut tension structure,its stiffness comes from the effect of prestress on the geometry,so it is necessary to accurately calculate the size and prestress of each component in the design.For the cable-stayed bridge and suspension bridge structure,it is also necessary to accurately control the force and size of the cable to make the force distribution of the bridge reasonable and meet its performance requirements.Under the action of external force,the strain of steel cable will change with time,resulting in creep strain,which affects the performance of steel cable.Therefore,it is important to study the long-term creep behavior of steel cables for the design,use and maintenance of structures.At present,there are few researches on the long-term creep of steel cables at room temperature.In this paper,several groups of small diameter wire ropes are tested for long-term creep for 10900 hours,and the creep development law of wire ropes is studied qualitatively.The creep process is divided into three parts:linear creep stage,deceleration creep stage and long-term creep stage.Then,the finite element model of steel wire rope is established by using the method of ANSYS refined modeling,and the creep strain calculated by the model is consistent with the test data by adjusting its parameters,so as to obtain the method of ANSYS finite element simulation of steel wire rope creep.The internal mechanism of creep of steel wire rope is explained by creep test of single steel wire and cross section analysis of steel wire rope simulated by ANSYS.According to the test data and ANSYS finite element simulation data,the creep strain time curve of wire rope is fitted.Firstly,according to the regular of the curve,the equation form of deceleration creep stage is derived based on the viscoelastic theory.Then,according to the beginning and end points of deceleration creep stage,the linear creep stage and long-term creep stage are fitted linearly,and the constitutive equation of normal temperature creep of wire rope is obtained.Finally,the creep strain calculated by the equation is compared with the experimental data and ANSYS finite element simulation data to verify its accuracy.The creep constitutive equation is modified through the short-term creep test of large diameter wire rope and ANSYS refined modeling,and the creep constitutive equation suitable for large diameter wire rope is obtained.Then,the specific application scope of the creep constitutive equation proposed in this paper is determined from many aspects.Finally,the creep constitutive equation is used to calculate the longer-term creep strain level of the wire rope,and the influence of the creep effect on the performance of the wire rope is evaluated.It is pointed out that the influence of the long-term creep on the structural performance should be paid attention to in practical engineering,and corresponding measures should be taken.