钢绞线吊杆弯曲转角对其力学性能及疲劳寿命的影响

Influence of bending angle of steel strand suspender on mechanical properties and fatigue life

为了得到不同轴偏转角对拱桥吊杆力学性能及疲劳寿命的影响,对吊杆的基本单元1860级Φs15.2七丝钢绞线进行了研究。对钢绞线进行6个轴偏转角(0、3、6、9、12、15mrad)的静载拉伸试验,并利用ANSYS Workbench进行有限元模拟验证,随后利用ANSYS Workbench与Ncode Design联合仿真模拟得到不同轴偏转角对钢绞线疲劳寿命影响规律。结果表明:钢绞线的破坏发生在锚固端,其破断力随轴偏转角增大而减小,并且减小的幅值也随之增大。轴偏转角为15mrad时,破断力降低约12%;钢绞线的疲劳寿命随轴偏转角增大而减小,疲劳破坏点主要出现在外丝锚固端。轴偏转角达到15mrad时,当应力幅分别为250MPa和300MPa时,钢绞线疲劳寿命均减小15%以上。

In order to investigate the influence of different axial deflection angles on mechanical properties and fatigue life of arch bridge suspender,a study was conducted on the basic unit of the suspender,1860 gradeϕs 15.2 seven wire steel strand.The static load tensile test of steel strand at 6 deflection angles(0,3,6,9,12,15mrad)was carried out,and finite element simulation verification was carried out by using ANSYS Workbench.Subsequently,ANSYS Workbench and Ncode Design were used to jointly simulate the influence of different axial deflection angles on the fatigue life of steel strands.The results indicate that the failure of the steel strand occurs at the anchorage end,and its breaking force value decreases with the increase of the axial deflection angle,and the amplitude of the decrease also increases accordingly.When the axial deflection angle is 15mrad,the breaking force value decreases by about 12%;The fatigue life of steel strands decreases with increasing deflection angle,and the fatigue failure point mainly occurs at the outer wire anchorage end.When the deflection angle reaches 15mrad and the stress amplitudes are 250MPa and 300MPa respectively,the fatigue life of the steel strand decreases by more than 15%.