Analytical Chatter Stability And The Factors Affecting The Stability Of Milling System

The cutting chatter in milling process is the main factor which affects the stability of the system,prevents high efficiency and high precision in machining.Choosing reasonable machining parameters such as radial cutting depth and the axial cutting depth and the spindle speed is a precondition of avoiding chatter during the machining process.This text aimed at the reseach of milling chatter has done the following work:1.Establishing the geometry model and dynamic model of spiral milling cutting system according to the straight tooth cutter and vertical tooth cutter respectively.2.This paper expounds the Floquet stability criterion and then introduces the time finite element analysising method(TFEA)adopting the method of piecewise cubic Hermite interpolation to solve the differential equation of the milling system with time-delay motion.Then the finite element method is used for mapping the stability lobes diagram of system considering the spiral angle,radial immersed in the cutting process and the modal parameters of the cutter arbor.Getting the cutting force and vibration displacement diagrams and the Poincare maps of the tip point by using time-domain simulation method for some specific working conditions.Judging the stability of the system under certain working condition by using the simulation graphics.Then estimating the accuracy of the SLD used time domain method by comparing the consequences got from the time-domain simulation and TFEA respectively.In addition,this article also discusses the method of single frequency principle and steps of the mapping SLD.3.When the spindle speed of the milling system is greater than ten thousand(rpm),the influence of the gyroscopic effect on the stability of the system is non-ignorable.In this paper,the last chapter discusses the gyroscopic impact on the natural frequency of the tool.By the relationship between natural frequency of tool and the rotational speed of tool the consequence is got.By comparing the amplitude-frequency curves of the tip point displacement transfer function considering and not considering gyroscopic effect the following consequence is got.At last the stability lobes diagram of milling system considering the gyroscopic effect is got.