Detection Principle And Experiment Research Of Wire Rope's Tension Based On The Magnetic Parameters

Because of its advantages of stable and reliable operation,good bending property and flexibility,the wire rope is often regarded as an ideal tension member and widely used in elevator lifting,transportation and mining.As a key component of equipment subjected to tension,the wire rope not only withstand normal working load,but also by the impact of uncertain load.The actual state of the wire rope is a reference to judge the safety of its use.The safe use of wire rope are closely related.to the normal production and life safety.Therefore,the research of rope tension detection method has important practical significance.In this paper,the method of detecting the tension of steel wire rope based on magnetic characteristic parameters is studied emphatically.The research work has been completed as follows:(1)The wire rope is a ferromagnetic material.Starting from the material characteristics of the wire rope,the source of the magnetism is explained.The influence of the external excitation field on the magnetic domain structure of the ferromagnet is analyzed,which is mainly through the movement of the magnetic domain and the displacement of the domain wall to reached.Summed up the characteristics of the various stages of magnetization.(2)The magnetostrictive effect and magnetophoretic effect of ferromagnet were studied.The influence of tension on the magnetic domain structure of ferromagnet was deeply analyzed from two aspects of microstructure and energy change.The relationship of tension and magnetic flux density,permeability is analyzed.The calculation method of magnetic induction and magnetic permeability are deduced.Finally,the mathematic model of tension detection of steel wire rope based on magnetic induction and permeability are established.(3)The characteristics of wire rope tension detection devices for all kinds of closed magnetic circuits and non-closed magnetic circuits are analyzed and compared.An open structure sensor and a sleeve structure sensor were developed.By comparing the excitation uniformity of the two,the experimental results show that two sensors can achieve the effect of uniform excitation in a certain area.Compared with the open structure sensor,the magnetic induction generated by the sleeve structure sensor is higher.The design criteria of field magnetic circuit are summarized and the magnetic field generated by the coil is analyzed to determine the length and diameter of the coil,designing the magnetic circuit structure,analysing the magnetic circuit to determine the parameters such as the number of turns,the diameter and the working point of the sensor.Based on these,design and manufacture the sleeve rope tension detection sensor.(4)Design and manufacture the wire rope tension testing system based on the magnetic characteristics of the parameters,validated by the above theoretical analysis of the rationality.There are many factors that affect the output signal of the sensor.In this paper,the experimental program are designed according to the six parameters of excitation frequency,excitation voltage and type,specimen size,lift-off value and tension.Analysis their respective effects on the sensor output signal,as well as the impact of multiple parameters on the sensor output signal,which can provide a reference for the future selection of reasonable experimental parameters.