| Transportation is an important link in mine production.Mine transportation accidents have always accounted for a large proportion of various mine safety accidents.At present,inclined shaft hoisting transportation accounts for a significant proportion in the entire mine transportation system.The steel rope used for inclined shaft hoisting is an elastic body.During the hoisting process,if the movement state changes(acceleration,deceleration,etc),the steel rope will store or release energy,causing severe vibration of the hoisting container.Due to the presence of wheel-rail defects such as unevenness of the rail and wheel damage,vibration phenomena commonly occur when the mine truck run on the track.In order to avoid abnormal vibration of the traction steel rope and inclined shaft mining trucks during the operation of the inclined shaft hoisting system and improve the safety and stability of the inclined shaft hoisting system,it is necessary to clarify the dynamic characteristics of the traction steel rope and the vertical vibration characteristics of the inclined shaft mining trucks during the working of the inclined shaft hoisting system.This article adopts theoretical analysis,experimental verification and comparative analysis methods to conduct a systematic study on the dynamic characteristics of traction steel ropes and the vertical vibration characteristics of inclined shaft mining trucks,which provides analytical ideas and theoretical basis for the related research of the inclined shaft hoisting system.The calculation formula of quasi-static tension of traction steel rope was given.Based on the "energy method",the calculation formulas of the maximum deformation and maximum tension of the traction steel rope after the inclined shaft hoisting system loosening and emergency braking were derived.Based on the lumped parameter method and Rayleigh method,the axial vibration mechanical model of the rope end of the inclined shaft hoisting system was established.Based on the kinetic energy theorem,the axial vibration equation of the rope end was derived.Simulink was used to simulate the axial vibration response of the rope end when the inclined shaft hoisting system is lifted and lowered under heavy load.The control variates method was used to study the influence of different acceleration,acceleration change rate,load mass and maximum running speed on the axial vibration and dynamic tension of the rope end.Based on the structural characteristics of large mining trucks,a vertical vibration model of inclined shaft mining trucks was established with a 1/2 structure.Based on the structural characteristics of the track and the low-speed operation characteristics of the inclined shaft mining truck,the track system was simplified as an Euler-Bernoulli beam placed on a single-layer continuous viscoelastic foundation.The vertical coupling vibration model of mining truck and rail includes the vertical vibration model of mining truck and the rail vibration model.Their coupling relationship is specifically reflected in the interaction force between the wheel and rail.The Newmark-β integral method was used to numerically solve the vertical vibration response of the inclined shaft mining truck.Based on the power spectrum of track irregularity,the inverse Fourier method was used to achieve numerical simulation of vertical random track irregularity time-domain samples.In the time-domain dynamic simulation of mining trucks,it is necessary to input the geometric irregularities of the track as excitation into the dynamic model.A vertical vibration experimental platform of inclined shaft mining trucks was built.The vertical coupling vibration model of mining trucks and tracks was experimentally verified.Based on the vertical coupling vibration model of mining trucks and track,the control variates method was used to analyze the influence of tramcar running speed,car body mass(load)and shaft stopper stiffness on the vertical vibration of mining trucks.This thesis has 54 figures,9 tables,and 92 references. |
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