高周疲劳损伤下Q345等边角钢受力性能试验研究

为研究风荷载作用下输电线路中Q345等边角钢构件在不同的初始高周疲劳损伤下对其受力性能的影响，通过对1组无初始损伤构件和3组带不同初始疲劳损伤Q345等边单角钢试件的低周往复加载试验，得到了各组试件的承载力、刚度退化及滞回耗能等变化规律。研究结果表明：在低周反复荷载作用下，当初始高周疲劳振动从0次最终增加至4.0×104次时，试件承载力降低了36.1%，刚度降低了75.4%，累积耗能系数降低了57.4%，并最终导致构件累积损伤破坏。

Experimental study on axially loaded behavior of Q345single angle under high cycle fatigue

In order to research the influences of different initial high cycle fatigue damages under wind load on Q345 angle in transmission towers, a set of Q345 equilateral angle specimens undamaged and three sets of Q345 equilateral angle specimens damaged by different initial high cycle fatigue were investigated through low cycle reversed loading experiments. The change rules of the ultimate bearing capacity, stiffness degradation and hysteretic energy dissipation of the different specimens were obtained. The results show that the ultimate bearing capacity, stiffness degradation, hysteretic energy dissipation are reduced by 36.1%, 74.5% and 57.4% respectively, along with initial high cycle times increased from 0 to 4.0×104 under low cycle load, the accumulated failure is resulted at last.