Damage Formation And Evolution Characteristics Of High Energy Efficiency Milling Cutter And Its Trans-scale Design Method

Under the influence of a high-speed,interrupted-cutting impact load,the damage degree quickly increases following any structural damage in the milling cutter.The presence of structural damage must be explored given that these conditions may result in irreparable and serious accidents if not immediately detected.The milling cutter damage has multi-scale characteristics,thereby the single-scale damage research method can not reveal the formation and evolution of multi-scale damage of milling cutter,which makes it difficult to identify and control the damage of milling cutter.Under the support of National Natural Science Fund,named as “Multi-scale coupling mechanism of nonlinear friction dynamics wear of high energy efficiency milling cutter”(51875145),the multi-scale damage characteristics of milling cutter are studied,and the formation and evolution process of milling cutter damage are revealed.Then,the damage response characteristics of milling cutter and and its influencing factors are analyzed,and a trans-scale correlation design method of milling cutter is put forward.The damage scales of a milling cutter are divided according to the multi-scale characteristics of milling cutter damage.Based on continuum mechanics,the dislocation theory,and molecular dynamics,the damage characterization method of the macrostructure,lattice structure,and mesoscopic structure of a milling cutter were proposed in this study.Utilizing the multi-scale finite element method and the force connection method,the loading boundary conditions of the multi-scale damage of a milling cutter were established in order to achieve a trans-scale load transfer.The damage characteristics of the macrostructure,lattice structure,and mesoscopic structure of the milling cutter were studied,and the critical value of the multi-scale damage characteristic variable of the milling cutter was obtained.Thereby,the damage position,types,size,and damage occurrence sequences of the milling cutter were revealed,and the damage formation process and the characteristics of the milling cutter were clarified.Based on this,a method for recognizing the multi-scale damage in a milling cutter was proposed and verified by experiments.According to the dynamic characteristics of the cutting load of the milling cutter,the multi-scale damage identification method of the milling cutter is used to reveal the multi-speed change process of the damage variable of the macro and meso structure of the milling cutter.Based on the transformation characteristics of the valence bond fracture quantity,potential energy and damage equivalent value-added rate of the super-cell of the milling cutter components,the criterion of the mesoscopic damage nucleation and damage extension of the milling cutter is constructed,and the formation and evolution process of the mesoscopic damage of the milling cutter is identified.Based on the response characteristics of the mechanical properties of the milling cutter components,the effective correlation of the multi rate damage process of the macro and meso structure of the milling cutter is realized.The diversity of damage formation and evolution process of milling cutter is characterized by Deborah number,and the damage formation and evolution mechanism of macro and meso structure of milling cutter is identified.The response surface method is used to design the simulation scheme,and the damage response surface models of the macrostructure,lattice structure and mesoscopic structure of the milling cutter are established.Thereby,the relationship between the damage influencing factors of milling cutter and the damage characteristics is revealed.Under the interaction of rake angle,rotation speed,cutting depth and feed per tooth,the response characteristics of damage formation and evolution process of milling cutter and the damage degree of milling cutter are analyzed.The sensitivity of damage of milling cutter with different sizes and types to the damage influencing factors is analyzed,and the optimal scheme of influencing factors of milling cutter damage is given,which provides the basis for trans-scale correlation design of milling cutter damage.The damage model control variables of the milling cutter components are extracted,and the function of the milling cutter parameters is decomposed based on the axiomatic design.The evaluation model of damage degree and evolution mechanism of milling cutter is established,and a method for trans-scale correlation design of milling cutter is proposed.This method can restrain the damage of milling cutter by controlling the formation and evolution process of damage,and the effectiveness of the method is verified by comparative experiments.