Simulation Analysis And Experimental Research On Vibration Cutting Mechanism Of Metal Matrix Composites

Particle reinforced metal matrix composites have good mechanical properties,but because of the existence of reinforced particles,it is difficult to process.The ultrasonic vibration cutting technology shows the advantages in the processing of difficult-to-machining materials,but the research on the vibration cutting of the particle reinforced metal matrix composites is more biased in the macro experimental research.The aim of this study is to clarify the mechanism of vibration cutting of particle reinforced metal matrix composites from the meso level,which is of great guiding significance for further optimization of the processing technology.By analyzing the particle reinforcement theory and the composite preparation principle of particle reinforced composite,the geometric parameters of particle reinforced phase were determined.Based on the finite element simulation theory of particle reinforced composites,the characteristics and properties of each phase material,especially the interface,are analyzed,and the geometric and grid models are reasonably simplified.The influence of particle distribution mode on the model is discussed,and the orthogonal cutting geometry model of particle reinforced composites is determined.In addition,based on cutting simulation theory,the material modeling and damage failure model of workpiece is determined.Based on Python language,the secondary exploration of ABAQUS pre-processing process has been carried out,realizing parameterized rapid modeling.The algorithm which can make particles have variable volume fraction,variable size,random particle distribution and no crossover is studied.And,the finite element model is established,which can reasonably reflect the distribution of stress and strain and various working conditions of the material(the position of the particles in the upper,middle and lower positions of the cutting path).By defining the same material properties of the particles as the matrix,the cost of the model verification is reduced,and the purpose of observing the change of the cutting mechanism after the addition of the reinforced particles is realized on the basis of the same geometric model.The rationality of the modeling method is verified by designing vibration cutting experiments.Based on the model,the vibration cutting mechanism of particle reinforced metal matrix composites is studied.The effects of reinforced particles and vibration impact on the cutting force of the workpiece material,the quality of the machined surface,the transfer of stress and the initiation of the initial crack are studied respectively.The stress transmission mechanism of stress tends to be passed between particles pairs is revealed.It also reveals that vibration cutting can make the matrix around the particles produce the starting crack in a moment,and then cut off the 'channel' of the partial stress between the particle pair,which causes the stress concentration at the crack tip to accelerate the vibration cutting mechanism of the crack growth.Making full use of this characteristic and optimizing the processing parameters combined with particle parameters(volume fraction and particle size)is one of the important research directions in the future.