Peripheral Milling Operations Research Articles

Stability Prediction for Low Radial Immersion Milling

Traditional regenerative stability theory predicts a set of optimally stable spindle speeds at integer fractions of the natural frequency of the most flexible mode of the system. The assumptions of this theory become invalid for highly interrupted machining, where the ratio of time spent cutting to not cutting (denoted ρ) is small. This paper proposes a new stability theory for interrupted machining that predicts a doubling in the number of optimally stable speeds as the value of ρ becomes small. The results of the theory are supported by numerical simulation and experiment. It is anticipated that the theory will be relevant for choosing optimal machining parameters in high-speed peripheral milling operations where the radial depth of cut is only a small fraction of the tool diameter.

Integration of Process Simulation in Machining Parameter Optimization

In recent years, simulation tools have proven valuable for the prediction of machining state variables over a wide range of operating parameters. Such simulation packages, however, are seldom an integral part of machining parameter optimization modules. This paper proposes a methodology for incorporating simulation feedback to fine-tune analytic models during the optimization process. Through a limited number of calls to the computationally expensive simulation tools, process parameters may be generated that satisfy the design constraints within the accuracy of the simulation predictions, while providing an efficient balance among parameters arising from the functional form of the optimization model. The following iterative algorithm is presented: (i) a non-linear programming (NLP) optimization technique is used to select process parameters based on closed-form analytical constraint equations relating to critical design requirements, (ii) the simulation is executed using these process parameters, providing predictions of the critical state variables. (iii) Constraint equation parameters are dynamically adapted using the feedback provided by the simulation predictions. This sequence is repeated until local convergence between the simulation and constraint equation predictions has been achieved. A case study in machining parameter optimization for peripheral finish milling operations is developed in which constraints on the allowable form error,Δ and the peripheral surface roughness, Ra, drive the process parameter selection for a cutting operation intended to maximize the material removal rate. Results from twenty machining scenarios are presented, including five workpiece/tool material combinations at four levels of precision. Achieving agreement (within a 5% deviation tolerance) between the simulation and constraint equation predictions required an average of 5 simulation execution cycles (maximum of 8), demonstrating promise that simulation tools can be efficiently incorporated into parameter optimization processes.

An accuracy model for the peripheral milling of aluminum alloys using response surface design

In the peripheral milling process, the helical end mill is deflected easily by cutting forces, which results in inaccuracy of the machined surface of the workpiece. Since the cutting conditions involve various cutting parameters and working materials, how to model the multi-variable cutting process and select the appropriate cutting conditions which satisfies the accuracy requirement is an important problem in the present work. A dimensional-accuracy model for the peripheral milling of aluminum alloys under dry and down-milling conditions is presented. The model is postulated as a second-order equation and developed in terms of the Brinell hardness of the workpiece, the cutting speed, the feed, radial and axial depths of cut. To build the quadratic model and minimize the number of experiments for the design parameters, response surface methodology (RSM) with an orthogonal rotatable central composite design is used. By means of variance analyses and additional experiments, the adequacy of this model is confirmed. The model will be very useful in selecting cutting conditions to meet the accuracy requirement in peripheral milling operations. Using the model, the effect of each of the cutting parameters on the dimensional accuracy is analyzed. It is shown that the peripheral milling accuracy will be reduced with increasing values of workpiece hardness, feed, radial and axial depths of cut, but increased when a high cutting speed is employed. It is found also that the radial and axial depths of cut have the most significant influence on the accuracy in the peripheral milling aluminum alloys.

Force prediction models and CAD/CAM software for helical tooth milling processes. II. Peripheral milling operations

The domain of the many process variables for peripheral milling operations has been established and used for the identification, numerical assessment and experimental verification of the appropriate predictive force model as well as the development of cutter design strategies. The ‘eccentricity’ model has been shown to be the appropriate model for peripheral milling operations where the average, peak and fluctuating forces, torque and power are to be predicted. The simpler ‘ideal case’ model proved useful for predicting the average forces and torque as well as locating the conditions for zero or minimum fluctuations from explicit mathematical equations derived from the model. The ‘eccentricity’ model has been experimentally verified and shown to give good quantitative predictions. Based on the models strategies for cutter design have been developed and used to explain, and recommend improvements to, the rationalized commercial cutter designs. The unified mechanics of cutting approach and modular software ...

A Note on the Significance of the Quasi-Mean Resultant Force and the Modelling of Instantaneous Torque and Forces in Peripheral Milling Operations

Technical Briefs A Note on the Significance of the Quasi-Mean Resultant Force and the Modelling of Instantaneous Torque and Forces in Peripheral Milling Operations I. Yellowley I. Yellowley Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada L8S4L7 Search for other works by this author on: This Site PubMed Google Scholar Author and Article Information I. Yellowley Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada L8S4L7 J. Eng. Ind. Aug 1988, 110(3): 300-303 https://doi.org/10.1115/1.3187885 Published Online: August 1, 1988 Article history Received: December 10, 1987 Online: July 30, 2009

Analysis of cutting forces in peripheral and face milling operations

The paper describes au analytical method for evaluating the cutting forces arising in (i) peripheral and (ii) face milling operations. A single shear plane model has been used to analyse the cutting action at. each tooth. A good correlation between the analytical force values and the corresponding values obtained experimentally has been observed.