Research On Quasi Intermittent Vibration Assisted Swing Turning Cutting Force And Tool-chip Friction Characteristics

Difficult-to-process materials such as titanium alloys,ceramics,and ferrous metals are widely used in many fields such as aerospace,weapons,and biomedicine.While how to process difficult-to-process materials with high efficiency and low cost is the main problem at present.Vibration assisted swing cutting(VASC)is a quasi-intermittent cutting method for difficult-to-process materials.At present,the researches about VASC mainly focus on device designing,cutting performance testing and so on.However,the cutting force and tool-chip contact friction characteristics during the process of VASC cutting have not been effectively revealed.Therefore,this thesis conducts research mainly from these perspective.The main research contents are as follows:(1)First,the cutting principle of the VASC device was explained and analyzed with combination with the VASC device independently designed by this research group,and the tool point movement trajectory model was established in this thesis.This thesis also discussed how the tool point movement trajectory was generated and the change rule of the movement trajectory.(2)Second,a cutting force model of VASC was proposed in this thesis.This thesis analyzed the change relationship between instantaneous shear angle and cutting speed in VASC cutting process by using thin shear surface theory,and discussed the change of cutting force in normal plane,rake face and shear plane.Moreover,according to the geometric relationship between the maximum shear stress theory and the force in the cutting process,it also analyzed the relationship between the relevant angles and time “t” to establish an analytical model of cutting force.The influence of cutting angle,amplitude,cutting speed and cutting depth on cutting force was analyzed by ABAQUS simulation software.(3)Third,this thesis established a tool-chip chip friction model that considers cutting transition layer.Shear slip theory was used to analyze the friction characteristics of tool-chip contact during VASC cutting.This model incorporated a chip conversion layer that is often overlooked by conventional friction models.The simulation of tool-chip friction,tool-chip contact length,stress-strain and other changes were analyzed by MATLAB simulation.The obtained simulation results were compared with existing data to verify the correctness of the proposed model.(4)The fourth part of thesis is about cutting experiments and verification of VASC.In order to verify the effectiveness of the proposed force model,cutting experiments were performed on commonly used copper rod materials.The Kistler three-way force gauge was used to collect the force data in the VASC process,and the collected force data was compared with the results predicted by the cutting force model to verify the correctness of the model.