矿用钢丝绳破断拉伸中断裂股数分析

Analysis of fracture strands number in breaking stretch of wire rope for mine

针对6股矿用钢丝绳破断拉伸试验仅能实现1股、2股、3股绳股破断,4股及4股以上同时破断出现概率很低的问题,分析其在破断过程中受力状况,阐述破断股数与拉伸轴向分力间的关系,提出欲获取更接近真值的破断力值,需改变钢丝绳卧式拉力试验机的夹持装具角度及夹持齿板长度。经多次试验,选择钢丝绳在破断过程中夹持角的合角为13°～17°,夹持长度保证2个钢丝绳捻距,可实现钢丝绳4股、5股乃至全部股数破断。指出钢丝绳破断试验的最小有效样品长度应为绳径的30倍,用于重要场所的提升矿用钢丝绳在悬挂前进行预张拉处理。

Aiming at only realizing one strand, two strands and three strands to break in breaking stretch test of 6 strands wire rope for mine, but four or over four strands breaking at the same time is little probability, to analyze strands＇ force state in breaking, the relationship between breaking strand number and stretch axial component force is expounded. It is pointed out that in order to obtain breaking force near to truth-value, the clamp angle and the clamp toothed plate length of wire rope horizontal type tensile testing machine need to change. After many times test, selecting whole angle of clamp angle is from 13°to 17°in wire rope breaking, clamp length ensuring 2 rope lay pitch, can realize four strands, five strands even whole strands to break. It is put forward that the minimum effective specimen length in wire rope breaking test should be 30 times of rope＇ s diameter, the wire rope for mine used in important place lifting should be pre-stretched treatment before suspension.