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Stability improvement and regenerative chatter suppression in nonlinear milling process via tunable vibration absorber

Moradi, H ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jsv.2012.05.032
  3. Publisher: 2012
  4. Abstract:
  5. In this paper, a tunable vibration absorber set (TVAs) is designed to suppress regenerative chatter in milling process (as a semi-active controller). An extended dynamic model of the peripheral milling with closed form expressions for the nonlinear cutting forces is presented. The extension part of the cutting tool is modeled as an Euler-Bernoulli beam with in plane lateral vibrations (x-y directions). Tunable vibration absorbers in x-y directions are composed of mass, spring and dashpot elements. In the presence of regenerative chatter, coupled dynamics of the system (including the beam and x-y absorbers) is described through nonlinear delay differential equations. Using an optimal algorithm, optimum values of the absorbers' position and their springs' stiffness in both x-y directions are determined such that the cutting tool vibration is minimized. Results are compared for both linear and nonlinear models. According to the results obtained, absorber set acts effectively in chatter suppression over a wide range of chatter frequencies. Stability limits are obtained and compared with two different approaches: a trial and error based algorithm and semi-discretization method. It is shown that in the case of self-excited vibrations, the optimum absorber improves the process stability. Therefore, larger values of depth of cut and consequently more material removal rate (MRR) can be achieved without moving to unstable conditions
  6. Keywords:
  7. Chatter frequencies ; Chatter suppression ; Closed-form expression ; Coupled dynamics ; Cutting forces ; Dashpots ; Depth of cut ; Euler Bernoulli beams ; Extended dynamics ; Lateral vibrations ; Material removal rate ; Milling process ; Non-linear model ; Nonlinear delay differential equation ; Optimal algorithm ; Optimum value ; Peripheral milling ; Process stability ; Regenerative chatters ; Self-excited vibrations ; Semi-active controllers ; Semi-discretization method ; Stability improvement ; Stability limit ; Tool vibrations ; Trial and error ; Tunable vibrations ; Algorithms ; Cutting tools ; Differential equations ; Discrete event simulation ; Speed control ; Milling (machining)
  8. Source: Journal of Sound and Vibration ; Volume 331, Issue 21 , 2012 , Pages 4688-4690 ; 0022460X (ISSN)
  9. URL: http://www.sciencedirect.com./science/article/pii/S0022460X12004178