| Cutting force is one of the most important physical quantities in CNC turning.The establishment of accurate prediction model of cutting force can provide an important basis for process parameter optimization,tool and fixture design,material machinability evaluation and tool wear estimation.In this paper,taking the CNC turning of 304 stainless steel as the research object,the prediction model of cutting force is established.The cutting parameters are optimized and the reliability analysis of the cutting system is carried out.The main research in this paper is as follows:Firstly,the finite element prediction model of cutting force based on ABAQUS is established,the finite element theory and modeling process are introduced,the distribution of workpiece stress and the change and distribution of tool and work-piece temperature are analyzed by finite element model,and the cutting force under different cutting conditions is predicted;In order to verify the validity of the finite element model to predict the cutting force,an unequal shear zone model based on the cutting mechanism was established.By using MATLAB numerical iterative analysis,the change law of the physical quantity and the cutting force value in the shear zone are calculated.The comparison between the finite element model,the shear zone model and the literature data,the validity of finite element model was verified and the accuracy of finite element model for predicting cutting force was higher than that of shear zone model.Secondly,to improve the efficiency of rough machining and minimize the cutting force,the multi-objective optimization software ISIGHT is integrated with ABAQUS to complete the simulation process automatically.NCGA multi-objective optimization algorithm is applied to optimize cutting parameters.In this process,in order to extract cutting parameters and simulation results,Python was used to ABAQUS further development.The script program for finite element simulation,the program for calculating the objective function and the program to read the objective function value from the result file were compiled.Thirdly,this paper take the cutting power in cutting process as the object of study,using the Optimal Latin Hypercube method extract sample points of the cutting parameters as input variables,calculate the corresponding cutting power as the output variable,establish the mathematical relationship between cutting power and cutting parameters was by response surface fun ction fitting and a performance function established on such a basis.Then,the reliability of the cutting process and the reliability of the failure probability to each cutting variable are analyzed by using the Monte Carlo digital simulation method and the AFOSM method respectivel. |
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