钢丝微动磨损的评定参数及理论模型研究

Research on the Evaluation Parameters and Theory Model of Fretting Wear between Steel Wires

以6×19点接触式提升钢丝绳作为研究对象,对其钢丝微动损伤过程进行了实验室模拟;在自制的钢丝微动磨损试验机上考察了钢丝试样磨损深度随微动磨损试验时间的变化,并采用接触应力与微动速度的乘积(pv值)和pv值与微动时间的乘积(pvt值)作为评价钢丝微动磨损深度变化的综合参数.结果表明:在相同接触载荷下,钢丝微动磨损深度随pv值增加而减小,磨损深度同pvt值之间基本呈线性关系;根据这种线性关系建立了钢丝微动磨损的理论模型,并用试验结果进行了验证;试验结果和理论计算结果吻合,误差较小,且该模型可应用于其它微动磨损工况.

A 6 × 19 point contact hoisting rope was used as an example to develop a model to evaluate the fretting wear behavior of a steel wire pair. Thus a series of tests were performed on a fretting wear test rig constructed in our lab to evaluate the fretting wear behavior of the steel wire pair in dry friction condition. The wear depth were measured and taken as the characterization parameter to describe the fretting wear in relation to fretting time. And the integrated parameter pv value and pvt value were introduced to replace the parameters such as contact load, fretting time, and fretting amplitude so as to depict the fretting wear behavior more thoroughly and to reveal the effects of those parameters on the fretting wear behavior more conveniently. Moreover, a theoretic model was developed to examine the fretting wear behavior of the steel wire pair, by fitting the linear proportion between the integrated parameter pvt value and the wear depth. And the applicability of the model was examined by comparing with the corresponding fretting wear test results. It was found that the fretting wear depth of the steel wire increased with increasing fretting time. At a fixed contact load, the decrease of the contact stress conformed to the increase of the contact area, which was related to the increase of the wear depth with increasing fretting time as well. At the same time, the wear depth of the steel wire decreased with increasing pv value and it was almost linearly proportional to the integrated parameter pvt value. Besides, the theoretic calculation results based on the model agreed well with the experimental ones, while the model could also be applied to other fretting conditions.