Study On Friction And Wear Characteristics Of Braided Wire Rope In Drawing Process

Braided wire rope is widely used in tension wire erection construction because of its unique braided structure,high strength,strong torsion resistance and good flexibility.In the process of wire erection,the working conditions of braided wire rope are complex,and it is repeatedly subjected to various loads such as tension,bending and torsion,and its working environment is harsh.It is often eroded by acid rain.Impurities such as sand and stone,rope shedding and other impurities stick to the rope body.Under the combined influence of the above factors,the rope body wears and accelerates fatigue fracture failure.The results show that the surface wear of the rope has a great influence on the mechanical properties of the rope,which is the main reason for the premature fracture failure of the rope.As the braided wire rope is pulled through the drum,the load is the most complex and the rope body is the most vulnerable to wear and tear.Therefore,this paper takes YS9-8*19 braided wire rope as the research object,carries out the research on the traction process mechanics and wear and fracture failure mechanism of braided wire rope,and provides theoretical support for the prediction of rope life and the optimization of traction mechanism,which has important theoretical value and engineering significance.Specific research contents are as follows:(1)Analysis of abrasion and broken wire mechanism of scrapped rope body: The splitting test and sample preparation of braided steel wire rope for scrap traction on site are carried out.The macro and micro morphology detection and analysis are carried out to observe the wear and wire breakage position.The micro morphology,structure and energy spectrum detection and analysis of the worn surface and wire breakage are carried out.The wear and wire breakage failure mechanism is determined based on the analysis of Tribological principle.According to the wear location,the rope wear can be divided into external wear and internal wear.(2)Research on External Wear and Construction of Wear Rate Model: The "winding-in-out" traction drum of the rope body passes through three states of "straight line-transition-bending" in turn.The contact wear between the rope body and the drum groove belongs to the external wear.The variation law of the tension of the wire rope in this processis analyzed,and the maximum tension position and the variation law of the tension are explored.The "rope-wheel" contact model is constructed to solve the number of contact points and contact stress between rope and groove.According to the basic principle of N.B.Cragelski's solid fatigue wear theory and the actual working conditions of tension line,the specific parameters are determined,and the relative wear model in winding process is constructed.Based on the model,the influencing factors of the external wear of rope are obtained.(3)Research on Internal Wear and Construction of Wear Rate Model: In the process of wire rope traction,the contact wear between the interstrand wire,the same core wire and the inner wire,the inner wire and the outer wire belongs to internal wear.According to the structure of the rope and its loading characteristics,the contact wear between strands is the main form of internal wear;The contact state between wire and rope during winding process is analyzed,and the number of contact points,the fretting distance between strands in transition and bending section and contact pressure are calculated;Two kinds of internal wear models are constructed: based on the geometric characteristics of wear marks,the geometric model Wj of interstrand wear is constructed;based on Archard's adhesion wear theory,the theoretical model Wl of interstrand wear is constructed,and the main factors affecting internal wear are obtained.(4)Friction and wear test in winding and traction process: Taking YS9-8*19 braided wire rope as a sample,the winding and traction process was simulated by means of the wire rope bending friction and wear test device,and the friction and wear test of the rope body was carried out.The wear and fracture position of the test sample,its macro and micro morphology and structure were tested and compared with the test results of scrap samples under actual working conditions.The wear width and depth of the rope were tested to obtain the test wear volume,and the wear volumes of the two internal wear models were calculated.The correctness of the internal wear model was verified by comparing the test and calculated values.The degree of internal and external wear under wheel diameter verifies the rationality of theoretical analysis of external wear and internal wear.