Research On Characteristic Identification Of Typical Joint Of Precision Machining Center Tool System

Chatter results in poor processing quality,excessive noise,potential damage to the spindle,and reduced tool life.Currently,the most effective way to avoid chatter is to plot the stability lobe diagram(SLD),and optimize cutting parameters to achieve stable cutting state.Plotting the SLD implies knowing tool point frequency response functions(FRFs),therefore,this paper is focused on the technology of dynamic characteristic identification with regard to typical joint of tool system during the prediction of tool point FRF.The main results are as follows:(1)Based on Timoshenko beam theories and Finite Element Method(FEM),the dynamic model of substructure is established.Using ABAQUS software to solve certain fixed beam four order natural frequencies,and comparing with the analytical solutions,the validity and accuracy of the ABAQUS software for solving the problem of substructure dynamics are verified.(2)Based on Receptance Coupling Substructure Analysis(RCSA),Timoshenko beam theories,and Particle Swarm Optimization(PSO),the spindle-holder cone joint equivalent dynamic parameters are identified.Comparing calculation and measurement of the FRFs of the spindle-holder end point,the results show the equivalent dynamic parameters of the identified spindle-holder cone joint are correct.(3)Based on the improved RCSA and Timoshenko beam theories,the identification model of tool-holder joint is established.The tool-holder joint equivalent dynamic parameters are identified by using PSO and Particle Swarm Optimization with Simulated Annealing Algorithm(SAPSO).The results show that the errors,refering to natural frequencies and FRFs magnitudes,between predictions and the experimentations are 3.48%and 9.49%,respectively.(4)A novel approach is described for quickly and accurately predicting machining center tool FRFs based on the improved RCSA and SAPSO.Taking the tool NO.2 as an example,the results show that the errors,refering to FRFs magnitudes and natural frequencies,between predictions and the experimentations are 9.37%and 4.02%,respectively.It verifies the robustness and accuracy of the proposed method.(5)Based on the Matlab GUI,a typical joint identification software of tool system is developed.Engineers can not only use this software to swiftly identify the equivalent dynamic parameters of tool-holder joint,but also predict FRFs of tool point when different tools are clamped.The research above provides a new idea to quickly and accurately identify the equivalent dynamic parameters of the typical joint on the precision machining center.