Research On Coupled Vibration Of Cable And Motion Characteristics Of Internal Wire In Construction Shaft

Wire rope is widely used in all kinds of hoisting system because of its good mechanical properties and characteristics of easy storage. However, the mechanical properties as stiffness and the relative motion of wires inside it should be investigated due to complex dynamic characteristics of hoisting system and special structure of wire rope itself. Wire rope is twisted by strands which is twisted by wires, so its structure is rather complex. When the wire rope in hoisting system is vibrating, the relative motion between the steel wires inside the wire rope will be generated, which may cause wear of wires and affect its service life. Cable guide is used on construction shaft, and the connection between hoisting cable and conveyance is usually constrained torsion or free torsion. The large torque caused by axial load will do damage to the connecting device and the hoisting cable itself when torsion is constrained. And hoisting cable’s rotation motion will be large when torsion is free. There is no reasonable evaluation of the two kinds of connection for the moment. The coupled vibration of hoisting sysetm in construction shaft, mechanical characteristics of wire rope, relative motion of the steel wire inside the wire rope under vibration condition and design method of steel wire rope according to different working conditions are invstigated by the method of theoretical analysis combining, computer simulation and field experiment.Firstly, this paper begins with studying the coupled vibration of hoisting sysetm in construction shaft. Vibration model of cable-guided hositing system is established based on Lagrange’s equations of the first kind. After that the vibration control equations are discrated by finite element, while the geometric matching conditions at the interfaces of the cables and conveyance are accounted for by the Lagrange’s multipliers. The ordinary differential equations are solved by numerical method. And the dynamic response of hoisting system are obtained while both the torsion is constrained and free.Secondly, studying on the mechanical characteristics of hoisting wire rope 18×7+IWS by numerical simulation. The finite element model of wire rope is established by software package ANSYS. The axial, torsional and coupled stiffness coefficient are given. And the influence of axial load on the distribution of stress and deformation inside wire rope is analysed.Then, studying on the realitive motion of wires inside wire rope. The linear expression of relative motion between steel wires is derived according to wire rope theory of Costello. The relative motion mainly is the rotate angle between cord core with inner strand and inner strand with outer strand. And its connection with vibration response of calble is established. The relation motion at the conditions of both the torsion is constrained and free is analysed and compared by example calculation.Finally, studying on the design method of wire rope considing the anti-rotation performance, tensile property, bending flexibility and contact condition. Analyse the main parameter that affect the performance of wire rope. And the theoretical reference to design wire rope according to different working condition is given.