钢绞线拉索疲劳性能优化试验研究

Experimental Study of Fatigue Performance Optimization for Steel Strand Cables

为了提高钢绞线拉索疲劳寿命,针对传统拉索锚固单元中的夹片小端内锥设计影响锚固区疲劳性能问题,基于钢绞线微动磨损机理,通过设置无内锥的夹片、增大夹片和锚杯的角度差对其疲劳性能进行优化,并验证该优化结构的锚固性能。制作采用传统及优化锚固单元的钢绞线拉索进行静载拉伸试验及疲劳试验,分析结构优化后的静载锚固性能及疲劳性能。试验结果表明:采用增大与锚杯角度差的夹片无需进行内锥设计也具有与小端内锥设计的夹片相当的静载锚固性能;采用优化锚固结构的拉索疲劳性能及经疲劳试验后的静载锚固性能符合标准要求且有较大富余,锚固区损伤较小,整索的疲劳寿命主要由索体非锚固段的疲劳性能决定。

For the traditional cable anchorages,the inner cone inside the hole cut at the small end of the splint has a degree of influence on the fatigue performance of the anchorage zone.In order to improve the fatigue life of steel strand cables,the splint without inner cone is proposed.Based on the fretting wear mechanism of steel strands,the fatigue performance of the splint is optimized via enlarging the angle difference between the splint and the anchor socket.And the anchoring performance of the optimized structure was verified.The steel strand cables with traditional and optimized anchor units were prepared to carry out static tensile test and fatigue test,to analyze the static anchor performance and fatigue performance of the structure after optimization.The results of the test show that enlarging the angle difference between the splint and the anchor socket allows the splint to have as equal as the static anchor performance of the splint with inner cone at the small end.For the cable with optimized anchorage structure,the fatigue performance and static anchoring performance after the fatigue test can meet the criteria and have large margin,with minimal damage in the anchorage zone.The fatigue life of the whole cable is determined by the fatigue performance of the non-anchored section of the cable.