同向捻捻法特点及对钢丝绳性能影响分析

Lang lay twist characteristic and its impact analysis on properties of wire rope

分析同向捻钢丝绳所述特点背后原因,拓展同向捻捻法对钢丝绳其他性能影响研究,并就钢丝绳报废标准因捻法不同而允许最多断丝数存在显著差异进行研究。同向捻钢丝绳耐磨损基于股中可视钢丝与匹配滑轮(卷筒)有较大的接触面积。柔软性好基于股中钢丝与绳芯接触面积小,以及组绳同层股与股间钢丝接触面积小。疲劳性能优基于:(1)钢丝捻制变形过程性能损失小;(2)耐磨损延缓了承载钢丝截面减小速度、钢丝表面裂纹产生速度及裂纹后续扩展速度;(3)柔软性好使绳内钢丝弯曲应力小;(4)改善外层股数相对较少的2层股钢丝绳抗旋转性。结构不稳定基于钢丝绳受垂直钢丝绳轴线挤压载荷时分开趋势更强。具有较大反拨力基于丝在股中、股在绳中具有相同松捻趋势和股具有较大的加捻应力。捻法对抗旋转性影响基于:(1)单层股钢丝绳只有交互捻才具有抗旋转性;(2)层绳捻法影响各自股所在层绳旋转力矩。同向捻和混合捻钢丝绳折返后因为钢丝绳间钢丝严重交叉而不适合加工套管固接折返式索具。标准规定同向捻钢丝绳报废最多可见断丝数少于交互捻因为股间钢丝可视长度大,最多可见断丝数仅是交互捻时之半乃基于1个捻距内单根钢丝出现可视部位频数仅为交互捻时之半。

To analyze the reason of lang lay wire rope described characteristics, develop impacting research of lang lay method on wire rope other properties, and standard of wire rope being discarded is researched while obvious difference ex- ists allowing maximum wire broken number because of different lay method. The wear resistance of lang lay wire rope is be- cause of large contacting area between visible steel wire in strand and matching pulley etc. Good softness is because of small contacting area between steel wire in outer strand and wire core, and small contacting area of steel wire between strand and strand of wire rope same layer. Good fatigue resistance is because of： （ 1 ） steel wire property loss is small in de- formation process ; （2） wear resistance prolongs loading steel wire cross section decreasing speed, steel wire surface cracks producing speed and cracks follow-up extension speed; （3）good softness causes small bending stress steel wire in rope; （4） the rotation resistance of outer layer strand comparatively few two layer strand wire rope is improved. The structure instabili- ty is because of wire rope separate trend stronger under vertical axis squeezing load. There is larger backwash force is be- cause of steel wire in strand, strand in rope have same slack twist trend and strand has larger twisting stress. Influence of lay method on rotation resistance is because of： （ 1 ） single strand wire rope only with regular lay has rotation resistance property; （2）layer rope lay method has influence layer rope rotary moment of each strand. Lang lay and mixed lay wire rope are unsuitable for producing sleeving fixed turn back sling after turn back because of steel wire in wire rope cross seri- ously. Standard stipulates that lang lay wire rope being discarded maximum visible wire broken number is less than that of regular lay because of visible length of steel wire in strand is large, maximum visible wire broken number is only half of regu- lar lay is because of frequency of single wire occurring visible part in one lay pitch is only half of regular lay.