起重機(jī)鋼絲繩受力復(fù)雜，受載時(shí)候，鋼絲中產(chǎn)生拉伸應(yīng)力、彎曲應(yīng)力、擠壓應(yīng)力（鋼絲繩于滑輪、卷筒之間相互擠壓）以及鋼絲繩捻制時(shí)的殘余應(yīng)力等。當(dāng)鋼絲繩繞過(guò)滑輪時(shí)，受有交變應(yīng)力作用，使金屬材料產(chǎn)生疲勞，最后由于鋼絲繩之間的摩擦、鋼絲繩于鋼槽的摩擦使鋼絲繩磨損而破斷。通過(guò)長(zhǎng)期的實(shí)驗(yàn)表明，起重機(jī)械鋼絲繩具有以下特點(diǎn)和規(guī)律：
The stress of the crane wire rope is complex. When it is loaded, tension stress, bending stress, extrusion stress (the wire rope is extruded between pulleys and drums) and residual stress of the wire rope are produced. When the wire rope passes through the pulley, it is subjected to alternating stress, which causes fatigue of the metal material. Finally, the wire rope is broken because of the friction between the wire rope and the friction between the wire rope and the steel trough. Long-term experiments show that the hoisting wire rope has the following characteristics and rules:
1、鋼絲繩的彎曲曲率半徑對(duì)鋼絲繩壽命的影響很大，這是因?yàn)槔K輪直徑減小時(shí)，鋼絲繩的彎曲變形加劇，彎曲應(yīng)力加大，因而鋼絲繩的磨損加快，疲勞損傷加快，鋼絲和繩的壽命就降低。
1. The radius of bending curvature of steel wire rope has a great influence on the service life of steel wire rope. This is because when the diameter of the rope wheel decreases, the bending deformation of steel wire rope increases and the bending stress increases, so the wear of steel wire rope accelerates, the fatigue damage accelerates, and the service life of steel wire and rope decreases.
2、鋼絲繩繞過(guò)繩輪時(shí)，繩輪于鋼絲接觸面之間的壓力和相對(duì)滑動(dòng)，使鋼絲磨損斷絲，接觸應(yīng)力越大，斷絲越迅速。
2. When the wire rope goes around the rope wheel, the pressure and relative sliding between the rope wheel and the steel wire contact surface make the wire worn and broken, and the greater the contact stress, the faster the wire broken.
3、鋼絲繩的結(jié)構(gòu)形式對(duì)其壽命影響也很大。點(diǎn)接觸鋼絲繩由于鋼絲之間接觸應(yīng)力大，鋼絲的交叉又增大了橫向壓力，強(qiáng)度損失要比先線接觸型大，抗疲勞性能也差，所以線接觸鋼絲繩比點(diǎn)接觸鋼絲繩壽命要長(zhǎng)。
3. The structure of steel wire rope has a great influence on its life. Because of the large contact stress between steel wires, the crossing of steel wires increases the transverse pressure, the strength loss is larger than that of the first contact type, and the fatigue resistance is also poor, so the life of the wire contact wire rope is longer than that of the point contact wire rope.
4、當(dāng)鋼絲繩一個(gè)捻距間的斷絲達(dá)到全部鋼絲繩的10%的時(shí)候，繼續(xù)使用鋼絲繩的斷絲速率明顯加快，短期內(nèi)即會(huì)出現(xiàn)斷股。
4. When the wire breakage between twists of a wire rope reaches 10% of the total wire rope, the wire breakage rate of using the wire rope is obviously accelerated, and the strand breakage will occur in a short time.
5、當(dāng)其他條件相同時(shí)，選用的鋼絲繩安全系數(shù)越高，其使用壽命越長(zhǎng)。
5. When other conditions are the same, the higher the safety factor of the selected wire rope is, the longer its service life is.
