Research On TBM Cutter Head Wear And Evaluation In Manufacturing

As the core component of the tunnel boring machine,the remanufacturing of the cutter head is the key part of the remanufacturing of the tunnel boring machine.Cutting disc wear reflects the mechanical properties of the cutting disc and the damage life,which are the key factors for remanufacturing.Based on the analysis of related research at home and abroad,this paper establishes a simulation model of cutter head excavation;based on the calculation of the excavation model,systematically analyzes the wear rule of the cutter head;based on a number of condition parameters that affect wear,a model of cutter wheel wear life prediction Based on the topology optimization analysis combined with the cutter head wear rule,the cutter head structure is optimized;the cutter head wear and other factors are used to comprehensively evaluate the cutter head remanufacturing.The specific research content is as follows:(1)In order to carry out a series of studies on cutter head wear,a simulation model of cutter head driving was established.Based on the calculation of the rock-breaking volume of the hob and the distribution of rock rock,the bed model of the rock particles was bonded in the EDEM.The constrained cutter head and hob model are imported into the established rock mass particle bed model for simulation analysis.In order to verify the correctness of the model,the cutter head load obtained by the simulation model of the tunnel was used as the input of the finite element mechanical model.The stress and strain of the cutter head was calculated and compared with the actual engineering statistical results to obtain a higher consistency.The establishment of cutterhead driving model has high reliability.At the same time,the load acquisition method is compared with the commonly used cutter disk load analysis method,which illustrates the simplicity of this method to obtain the cutter disk load.(2)Obtain the cutter wear rule.According to the simulation analysis of the cutting head driving simulation model,it is found that the areas where the cutting head wear first appeared in the panel near the exit groove and near the outside of the center hob,and then the wear spread from the outside to the inside.In order to further obtain the wear rule in each area of the cutter head,the analysis of the cutter head area shows that the areas where the hobs are densely distributed on the cutter head,the center panel and the panel near the exit groove are more severely worn.Finally,a detailed regularanalysis is made on the impact of cutter head driving distance,cutter head speed,wear layer height and wear constant on cutter head wear,laying a foundation for the wear prediction model and guiding the remanufacturing strategy of cutter head.(3)In order to improve the overall performance of the cutterhead,a topologically optimized method is combined with the analysis of the wear of the cutterhead panel to design a wear-resistant structure of a miter cutterhead panel.Compared with the old cutter head,it is obtained that the optimized cutter head has significantly reduced the stress and strain in the worn-out danger zone of the older cutter head,and the average wear amount is reduced by nearly double.Modal analysis shows that the natural frequencies of the first three orders of the rear panel are improved by 4.2%,3.4%,and6.5%,respectively,compared to the old cutter panel,which effectively enhances the rigidity of the cutter structure.The improved new cutter head panel has been significantly improved in terms of mechanical properties,abrasion resistance and stiffness,effectively extending the service life of the cutter head panel.(4)In order to obtain the cutter wheel wear life prediction model,the BP neural network optimized by genetic algorithm was used to predict the cutter wheel wear life.The predicted results fit well with the expected output.The accuracy of the cutter disk wear life prediction model is calculated to be 96.23%,which indicates that the model has a higher prediction accuracy,and it has a certain guiding effect on the cutter disk wear life prediction.(5)In order to establish a remanufacturing evaluation system for cutter heads,the TBM cutter heads after service are used as remanufacturing evaluation objects,and the remanufacturing value of cutter heads is evaluated step by step by using expert scores and layered analysis.First,quantitative analysis is performed on the nine indicators under the evaluation criterion layer(three parameters).Secondly,the quantified values of the three parameters introduced into the evaluation criterion layer are modified to obtain the comprehensive evaluation index of remanufacturing of the cutter head.Finally,based on this index,the remanufacturing of the cutter head is evaluated,so as to establish a relatively complete evaluation system.Based on the law of cutter head wear,reasonable suggestions for remanufacturing and repair are put forward.