Research On Influence Factors Of Wear And Reliability Analysis For Shearer Pick

The process of shearer cutting the coal body is essentially the process of shearer picks cutting the coal body.When picks cut the coal body,the coal body also reacts on the picks,resulting in the failure of picks.The wear of the picks is the most important reasons of cutter failure.It is of practical significance to grasp the main characteristics that affect the wear of the picks,to reduce the wear of the picks,to reduce the economic loss and improve the cutting efficiency of shearer.First of all,this paper introduced the relevant theory of cutting the coal body.Based on the understanding of the physical properties of the coal body,the force of shearer during cutting and the wear mechanism of shearer picks,the contact model between shearer picks and the coal body,build the abrasive wear model of cutting the coal body and the calculation model of the shearer picks,and then determine the four main parameters affecting wear of shearer picks contains:cutting speed,cutting depth,taper angle and cutting angle.Secondly,this paper uses numerical simulation software to analyze the impact of four main factors on the wear of picks under different parameters.Due to the great heterogeneity of coal,the cutting of the coal body by picks is random.The wear of picks is affected by many factors.In actual working conditions,it is difficult to study the influence of various influencing factors on the performance of the picks.It is difficult to realize the real-time monitoring of the pick status.Therefore,this paper uses the finite element software ANSYS/LS-DYNA simulation model,to establish a simulation model of cutting the coal body.Based on the above four main factors,make corresponding analysis plan,simulate the cutting process of the coal body.Through the dynamic finite element analysis and thermal coupling analysis of cutting the coal body,obtain the influence result of cutting speed,cutting depth,taper angle of picks and taper angle to the wear situation of the shearer picks,under different stress,stress distribution and temperature.Finally,analyze the influence status of the four main parameters,picks'material parameters and coal's material parameters on wear of shearer picks.Ensure several parameters that have a great influence on the life of the picks.On the basis of the simulation model established by ANSYS/LS-DYNA,set the four parameters and the four material parameters as variables.Using ISIGHT Latin sampling extract the samples of random variables and fitted by BP neural network method,Use FOSM method to calculate the reliability of the picks and the reliability sensitivity of each parameter.Verify the accuracy of the reliability by Monte Carlo method.By analyzing the reliability sensitivity of the non-dimensional mean of the picks,obtain the influence of each random variable on the reliability of the picks.It can provide the conclusion for the selection of the picks' parameter.