scholarly journals Semi-Active Magnetorheological Damper Device for Chatter Mitigation during Milling of Thin-Floor Components

2020 ◽  
Vol 10 (15) ◽  
pp. 5313 ◽  
Author(s):  
Santiago Daniel Puma-Araujo ◽  
Daniel Olvera-Trejo ◽  
Oscar Martínez-Romero ◽  
Gorka Urbikain ◽  
Alex Elías-Zúñiga ◽  
...  

The productivity during the machining of thin-floor components is limited due to unstable vibrations, which lead to poor surface quality and part rejection at the last stage of the manufacturing process. In this article, a semi-active magnetorheological damper device is designed in order to suppress chatter conditions during the milling operations of thin-floor components. To validate the performance of the magnetorheological (MR) damper device, a 1 degree of freedom experimental setup was designed to mimic the machining of thin-floor components and then, the stability boundaries were computed using the Enhance Multistage Homotopy Perturbation Method (EMHPM) together with a novel cutting force model in which the bull-nose end mill is discretized in disks. It was found that the predicted EMHPM stability lobes of the cantilever beam closely follow experimental data. The end of the paper shows that the usage of the MR damper device modifies the stability boundaries with a productivity increase by a factor of at least 3.

Author(s):  
Alex Elías-Zúñiga ◽  
Jovanny Pacheco-Bolívar ◽  
Francisco Araya ◽  
Alejandro Martínez-López ◽  
Oscar Martínez-Romero ◽  
...  

The aim of this paper is to obtain the stability lobes for milling operations with a nonlinear cutting force model. The work is focused on the generation of stability lobes based on a formulation with Chebyshev polynomials and the semidiscretization method, considering a nonlinear cutting force model. Comparisons were conducted between experimental data at 5% radial immersion with aluminum workpiece and predictions based on Chebyshev and semidiscretization. In all cases, the use of nonlinear cutting force model provides better prediction of process stability conditions.


2017 ◽  
Vol 11 (6) ◽  
pp. 958-963
Author(s):  
Koji Teramoto ◽  
◽  
Takahiro Kunishima ◽  
Hiroki Matsumoto

Elastomer end-milling is attracting attention for its role in the small-lot production of elastomeric parts. In order to apply end-milling to the production of elastomeric parts, it is important that the workpiece be held stably to avoid deformation. To evaluate the stability of workholding, it is necessary to predict cutting forces in elastomer end-milling. Cutting force prediction for metal workpiece end-milling has been investigated for many years, and many process models for end-milling have been proposed. However, the applicability of these models to elastomer end-milling has not been discussed. In this paper, the characteristics of the cutting force in elastomer end-milling are evaluated experimentally. A standard cutting force model and its parameter identification method are introduced. By using this cutting force model, measured cutting forces are compared against the calculated results. The comparison makes it clear that the standard cutting force model for metal end-milling can be applied to down milling for a rough evaluation.


Author(s):  
Tamás G. Molnár ◽  
Tamás Insperger ◽  
S. John Hogan ◽  
Gábor Stépán

Regenerative machine tool chatter is investigated for a single-degree-of-freedom model of turning processes. The cutting force is modeled as the resultant of a force system distributed along the rake face of the tool, whose magnitude is a nonlinear function of the chip thickness. Thus, the process is described by a nonlinear delay-differential equation, where a short distributed delay is superimposed on the regenerative point delay. The corresponding stability lobe diagrams are computed and are shown numerically that a subcritical Hopf bifurcation occurs along the stability boundaries for realistic cutting-force distributions. Therefore, a bistable region exists near the stability boundaries, where large-amplitude vibrations (chatter) may arise for large perturbations. Analytical formulas are obtained to estimate the size of the bistable region based on center manifold reduction and normal form calculations for the governing distributed-delay equation. The locally and globally stable parameter regions are computed numerically as well using the continuation algorithm implemented in dde-biftool. The results can be considered as an extension of the bifurcation analysis of machining operations with point delay.


Author(s):  
Z. C. Wang ◽  
W. L. Cleghorn ◽  
S. D. Yu

Abstract In this paper, the stability analysis of turning process is performed based on a new cutting force model which includes the effect of ploughing force. This approach utilized the Laplace transform to identify the characteristic roots of the examined machining system. The stability of the machining system can then be determined by examining the locations of the characteristic roots. The stability curve for a specific turning process can then be plotted. The effect of different cutting force models on the stability is also investigated. The results clearly demonstrate some chatter phenomena observed by other researchers.


2012 ◽  
Vol 500 ◽  
pp. 20-25 ◽  
Author(s):  
Qing Hua Song ◽  
Xing Ai ◽  
Bing Guo

An alternative physical explanation for process damping where a distributed cutting force model, along with a function distribution over the tool-chip interface, is assumed, is described. An exponential shape function is used to approximate the force distribution on the tool-chip interface. The distributed force model results in a more complicated governing equation, a second-order delayed integrodifferential equation, which involves both a discrete and distributed delay. An approach to transform and normalize the governing equation of motion into a third-order discrete system is described and the state-space representation of the new system is obtained. The semi-discretization method is then used to chart the stability boundaries for turning operation.


Meccanica ◽  
2016 ◽  
Vol 52 (1-2) ◽  
pp. 35-44 ◽  
Author(s):  
Edouard Rivière-Lorphèvre ◽  
Christophe Letot ◽  
François Ducobu ◽  
Pierre Dehombreux ◽  
Enrico Filippi

2006 ◽  
Vol 2 (2) ◽  
pp. 167-179 ◽  
Author(s):  
R. P. H. Faassen ◽  
N. van de Wouw ◽  
H. Nijmeijer ◽  
J. A. J. Oosterling

The efficiency of the high-speed milling process is often limited by the occurrence of chatter. In order to predict the occurrence of chatter, accurate models are necessary. In most models regarding milling, the cutter is assumed to follow a circular tooth path. However, the real tool path is trochoidal in the ideal case, i.e., without vibrations of the tool. Therefore, models using a circular tool path lead to errors, especially when the cutting angle is close to 0 or π radians. An updated model for the milling process is presented which features a model of the undeformed chip thickness and a time-periodic delay. In combination with this tool path model, a nonlinear cutting force model is used, to include the dependency of the chatter boundary on the feed rate. The stability of the milling system, and hence the occurrence of chatter, is investigated using both the traditional and the trochoidal model by means of the semi-discretization method. Due to the combination of this updated tool path model with a nonlinear cutting force model, the periodic solution of this system, representing a chatter-free process, needs to be computed before the stability can be investigated. This periodic solution is computed using a finite difference method for delay-differential equations. Especially for low immersion cuts, the stability lobes diagram (SLD) using the updated model shows significant differences compared to the SLD using the traditional model. Also the use of the nonlinear cutting force model results in significant differences in the SLD compared to the linear cutting force model.


1994 ◽  
Vol 116 (3) ◽  
pp. 324-330 ◽  
Author(s):  
A. E. Bayoumi ◽  
G. Yucesan ◽  
L. A. Kendall

An analytic mechanistic force model has been developed to simulate the cutting forces in milling operations. Steps taken to develop the model consisted of cutter surface representation, chip removal kinematics, cutter force definition, and determination of the integration limits from the force equations. The cutter surface is represented by ruled surfaces that are a function of cutter geometry. Cutter forces are determined by integrating the pressure and friction loads acting on these cutter surfaces. The integration limits that are functions of the rotation angle are established. Several techniques dealing with the process parameters are discussed. The model uses process dependent parameters representing normal pressure, chip flow friction, and chip flow kinematics. The paper discusses how process data can be used to establish values for the parameters.


Sign in / Sign up

Export Citation Format

Share Document