On time-domain methods for milling stability analysis

Abstract

As a basic and advanced machining technique, the high-speed milling process plays an important role in realizing the goal of high performance manufacturing. From the viewpoint of machining dynamics, obtaining chatter-free machining parameters is a prerequisite to guaranteeing machining accuracy and improving machining efficiency. This paper gives an overview on recent progress in time domain semi-analytical methods for chatter stability analysis of milling processes. The state of art methods of milling stability prediction in milling processes and their applications are introduced in detail. The bottlenecks involved are analyzed, and potential solutions are discussed. Finally, a brief prospect on future works is presented. High speed milling is widely utilized in manufacturing of complex surfaces for the fields of aerospace, ship, automotive, dies and molds etc., due to its advantage of obtaining high machining accuracy and high material removal rate with keeping low-amplitude cutting forces. Regarding to modeling of machining processes, the research topics on high speed milling can be categorized as: tool path planning, machining dynamics and machining physical modeling. Tool path planning is to plan the tool path according to the workpiece model, machining strategy and required machined error [1][2][3][4][5]. From the viewpoint of machining dynamics, the relative vibration between the workpiece and cutter in the milling process is the main reason of reducing product surface quality and limiting the production efficiency. To suppress the vibration impact by optimizing the machining parameters, the following two questions need to be addressed.(1) Stability analysis based on the dynamics of milling processes. As far as chatter vibrations are concerned, there are four different mechanisms: regeneration [6], mode coupling [7], friction [8] and thermo-mechanics of chip formation [9]. In milling processes, regenerative chatter is the most common form of self-excited vibration to reduce surface quality and machining efficiency [10,11]. The works on analysis of the stability of milling processes focus on calculating the stability boundary of the machining parameters based on the dynamic models characterizing the milling processes.(2) Machining accuracy analysis on the basis of stability analysis. Due to forced vibrations in milling processes, chatter-free machining parameters cannot ensure high performance machining. Vibration-induced surface errors can be classified as surface location error (SLE) [12] and surface roughness [13]. It is essential to take the stability and dynamical errors into account in machining optimization models to achieve high performance milling.

Milling Stability Prediction with Multiple Delays via the Extended Adams‐Moulton‐Based Method

“…To numerically determine the milling stability, the governing equation (2) should be reexpressed in the state-space form. Specifically, define p( ) = Mq( ) + Cq( )/2 and y( ) = [q( ), p( )] ; (2) can be rewritten aṡ…”

“…The onset of such detrimental instability may result in poor surface roughness, rapid tool wear, and large reduction of tool life. Therefore, many researches on the modelling, prediction, and avoidance of milling chatter have been conducted [1][2][3]. Theoretically speaking, modecoupling, frictional, thermomechanical, and regenerative mechanisms can induce chatter to occur [4].…”

An Efficient Third-Order Full-Discretization Method for Prediction of Regenerative Chatter Stability in Milling

“…e main advance in the study of machining dynamics in the past few years has come in recognizing and interpreting a variety of different delay-differential equations (DDEs) that arise in the milling processes when considering the regenerative effects [4,5]. Stability lobe diagrams (SLDs) obtained with DDEs [6,7] are the most widely applied tools for revealing the boundary between stable (i.e., chatter-free) and unstable (i.e., with chatter) machining and locating their possible optimal chatter-free parameters (e.g., spindle speed and depth of cut). e theoretical advances in numerical analysis methods and the use of on-line computers for solving DDEs in machining process modeling have led to increased interest in creating SLDs for stable machining parameter selection.…”

A novel stability prediction method for milling operations using the holistic-interpolation scheme

“…5,6 The corresponding dynamics model can be formulated as delay differential equations (DDEs) with time-periodic coefficients. 7,8 Milling chatter has harmful effects on the workpiece quality, tool wear, and machining productivity. Consequently, many research efforts have been focused on the modeling, prediction, detection, and suppression of such detrimental vibration.…”