Research Of Wire Rope Damage Mechanism And Electromagnetic Sensing Detection Technology

The steel wire rope is widely used in many industries of the national economy for its good bearing capacity. Because of the generalized application of the steel wire rope, its safety operation has become the focus of attention. The steel wire rope will appear various forms of damage in use, such as wear, broken wire, corrosion, fatigue, etc. Regular detection of the steel wire rope must be done in order to avoid safety hazards generated from the damages. There are many types of detection sensors at home and abroad at present, and the detection performance of these sensors also differs. Therefore, through the in-depth study of the steel wire rope damage mechanism, this paper aims to design a portable steel wire rope detection sensor.This paper summarized the current situation of nondestructive testing of the steel wire rope at home and abroad, studied the electromagnetic sensing detection technology and introduced the basic knowledge of the steel wire rope damage and damage detection mechanism, including the structure, classification, characteristics and application, damage types and scrapping standards, as well as magnetization modes and intensity of the steel wire rope. The paper also further studied the damage detection mechanism of the steel wire rope based on the main magnetic flux detection principle and the leakage magnetic flux detection principle.Leakage magnetic flux detection was used to detect the LF steel wire rope damage. Firstly simulation model of broken wire using MATLAB was made, and then the simulation graphics about leakage magnetic field were gained. After that, corresponding relations between the length and depth of broken wire and the peak of leakage magnetic field were established according to the characteristics of leakage magnetic field. On this basis, permanent magnet excitation equipment that makes steel wire rope reach magnetic saturation was designed. According to the distribution characteristics of the leakage magnetic field, detection circuit boards composed by hall elements was designed and preliminary tests to the circuit were done.LMA steel wire rope damage detectionwas conducted through detecting the main magnetic flux. Firstly simulation model of the metallic section loss of the steel wire using MATLAB was made, and then the distribution diagram and condition of magnetic fluxline when steel wire ropes with different diameters show different degrees of section loss was gained. After that, corresponding relations between section loss percentages and number of magnetic flux line were established according to characteristics of magnetic lines across the steel wire rope, and then induction coil to detect LMA steel wire rope damage was chosen.Make sensors and perform damage detection experiments. The first step was the construction of the experimental platform, including the design of the sensor bracket, the choice of movement types of the steel wire rope, etc. Then, the sensor performance testing experiment and the steel wire rope damage signal detective experiment were conducted. Detection signal waveforms of different damages were gained through designing various damages of the steel wire rope, and the influence law of broken wire number and fracture width on detection signals was summarized by analyzing characteristics of the detection signal.This paper preliminary verified the feasibility of detecting sensor through the theoretical and experimental study of the steel wire rope damage, which laid a solid foundation for further study on nondestructive testing of the steel wire rope.