Effect of various kinematic parameters of mine hoist on fretting parameters of hoisting rope and a new fretting fatigue test apparatus of steel wires

Dynamic friction transmission and creep characteristics between hoisting rope and friction lining

“…The Rayleigh-Ritz method [1,3] is employed to deal with the tail rope one third of which is added to m 1 or m 2 ; the hoisting rope is also dealt with using the Rayleigh-Ritz method as shown in Eqs. (1)-(6).…”

“…During hoisting in deep and ultra-deep coal mines, the changing vertical rope length and inertial loads induce the system vibration and thereby the dynamic tensions of hoisting rope [1,3]. The rope bending over friction lining around the friction pulley subjected to tensions at both ends result in the elastic deformation of bending rope, and thus an elastic slip between the rope and friction lining, i.e.…”

“…Mine hoisting systems, connecting the underground production system and the ground industry square, are employed to hoist the coal, gangues, equipment and workers [1][2][3]. With the development of deep mining and requirements of safe and efficient production in large modern coal mines, multi-rope friction hoist systems, with the large hoisting capacity, large hoisting height, high safety coefficient, low consumed power, small size and the low cost, are widely employed in deep and ultra-deep (N1000 m) mine hoisting [4,5].…”

A Development and Application of the Fretting Fatigue Test Apparatus

“…Literature of fretting fatigue demonstrates that the fatigue load was imposed mostly by hydraulic actuator and occasionally by position control machine [7]; the contact pressure of fretting specimens is induced through the clamping pads attached to the proving ring, spring or other fretting fixtures. Geometries of the pads are flat, spherical, cylindrical, and bridge-type [3], [4], [8]- [10], but most specimens use flat fretting contact surface. Though there are diverse apparatus for fretting fatigue test, the design has to meet certain requirements to obtain efficient operation and results [11]: (i) the ability to produce a constant normal force between pad and specimen and the visibility of pad and specimen, (ii) a few microns relative movements, (iii) very high stiffness of the fixture, (iv) high precision of measurement.…”

“…Fretting is induced by vibrations or the application of bulk fatigue stresses to one or both of the contacting parts and widely occurs at the contact interface between two bodies when there is small amplitude oscillatory relative movement (typically 5-50 micrometers), such as dovetail assemblies in aircraft structures [1], [2], cables in overhead conductors [3] and mine hoist [4], riveted joints [5], prostheses [6], etc. At the edge of the contact there will be a stress singularity which results in early nucleation of cracks at the pad tip.…”