Research On Cutting Process System Dynamics Based On Receptance Coupling Substructure Analysis

High speed cutting has been widely used in the aerospace, automotive, mold manufactureand other fields owe to it’s outstand advantages, such as high efficiency, low cutting force andhigh precision. However, during the production process, chatter is a key problem, which resultsin poor surface, tools’ wear, even the damage of machine tool. In order to avoid chatter, it hassignificant engineering meaning to predict the cutting process stability，the dynamics of themachine cutting system need to be research thoroughly. Tool point frequency response function,which is reflect the dynamics of the cutting system on the tool point, an essential requirement fordrawing the stability lobes diagram, so it’s obtaining has key significance in the prediction of thecutting process stability. With the purpose of predicting high speed milling system stability, thedynamics of the high-speed milling system and the way to solve the milling stability has beenanalyzed, dynamics characteristics of motorized spindle has been researched. The research worksare as follows:The bearing damp effect was added in the original spindle dynamics model, based on thetransfer matrix method. Typical elements’ states of motorized spindle are established bymathematical method. The natural frequency, main mode and response of spindles are calculatedusing MATLAB.Based on the Euler-Bernoulli beam theory, the receptance coupling substructure analysiswas used to predict the tool point frequency response functions. This model divided the machinetool into three substructures. Determine the receptance of substructure by the Euler-Bernoullibeam model. Develop the connection model compose of linear and rotation springs and dampers,and the connection parameters has been solved. Coupling receptance of every substructure withthe solved connection model based on RCSA to obtain the tool point FRF.The dynamic model in milling process was built based on regenerative chatter vibrationtheory, the stability lobes diagram were drawn by analytical methods. Considering the millingforce coefficients will change with the vibration of spindle speed, a new regenerative chattervibration model was proposed. The milling stability was affect by milling force coefficientsdependent on spindle speed in case of different radial immersion ratios in low-speed andhigh-speed based on full-discretization method. It is found that milling force coefficientsdependent on spindle speed is very important on researching the stability in high speed milling inthe case of low radial immersion ratios.