Discrete Element Modeling Of Grinding Wheel Considering Surface Topography And Grinding Numerical Simulation

Compared with other machining methods,grinding is still an important method to achieve high-performance machining of parts.As the requirements for precision,reliability and service life of mechanical products continue to increase,higher requirements are put forward for grinding machining.Grinding is essentially a process in which a large number of discretely distributed abrasive particles on the surface of the grinding wheel interact with the material to be processed to achieve material removal.Each abrasive grain on the surface of the grinding wheel micro-cuts the material.However,due to its high cutting speed,strong randomness,and complex interaction between abrasive particles and work-piece,it makes the research of the material removal process more complicated.Most of the existing researches are based on the use of a single specific shape of abrasive particles instead of all abrasive particles of the grinding wheel.The simulation idea is not completely scientific.Since discrete element has certain advantages in modeling the topography of the grinding wheel,it can be further study the modeling of the topography of the grinding wheel and the law of material removal.This thesis introduces the discrete element method into the research of material grinding process,it realizes the discrete element modeling and grinding process simulation of the grinding wheel considering the surface topography.the thesis takes nickel-based alloy grinding as the research object.According to the inspection results of the surface morphology of the grinding wheel,several abrasive grains that conform to the actual contour are defined.The surface morphology of the grinding wheel is modeled,and the discrete element model of the nickel-based alloy is constructed and calibrated.The experiment and numerical simulation are used to study the influence of grinding wheel by morphology parameters and grinding parameters on the grinding process of nickel-based alloys.The specific research work is as follows:(1)Taking the surface morphology of 120# ceramic bond CBN grinding wheel as the simulation prototype,the super depth microscopic system inspects and analyzes of the grinding surface morphology of the sample block of 120# ceramic bond CBN grinding wheel and the production of 120#CBN powder of the grinding wheel,it is obtained the shape of the related abrasive particles,the particle size of the abrasive particles and the distribution of the abrasive particles on the surface of the grinding wheel.It provides a basis for the subsequent establishment of the surface shape model of the grinding wheel.(2)Based on the surface morphology of the grinding wheel and the detection results of the abrasive particles,the arc angle random cut method is used to profile and distribute geometric modeling of the abrasive particles on the surface of the grinding wheel.the thesis defined four types of random and two types of regularly arranged abrasive particles model for research;The nickel-based alloy material model was established using particle flow PFC2 D software;The parallel bond bonding linear calibration method was used to calibrate the mechanical properties of the material model to match the simulated mechanical properties with the actual material mechanical properties.The calibrated material model is used as a work-piece to study the simulation of grinding wheel grinding.(3)Combined with the grinding wheel surface morphology model and the nickel-based alloy model,a discrete element simulation of the dynamic grinding of the grinding wheel nickel-base alloy was established.Under different processing parameters,the influence of abrasive grain profile and arrangement on the grinding process was studied.In order to verify the simulation results,experiments related to the grinding of nickel-based alloys were carried out.It performs quantitative or qualitative analysis on the discrete element simulation model of the grinding wheel with randomly distributed abrasive particles.The feasibility of discrete element method for nickel-based alloy grinding simulation is verified,and it provides reference for the research of material grinding process.