Machining Dynamics

Abstract This paper is concerned with the dynamic stability of nonlinear chatter leading to instability machining at a Hopf bifurcation point. Regions of stable and unstable chatter machining are identified in an infinite-dimensional space for a reasonable and fixed time delay between successive cuts. The influence of nonlinear cutting force as a function of the chip thickness and feed rate, and parametric excitations on machining dynamics have been characterized.

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An Optimal Feed Interpolation Algorithm for High-Speed Five-Axis Machining

Materials Science Forum ◽

10.4028/www.scientific.net/msf.532-533.873 ◽

2006 ◽

Vol 532-533 ◽

pp. 873-876 ◽

Cited By ~ 4

Author(s):

Yu Han Wang ◽

Jing Chun Feng ◽

Yu Hao Li ◽

Ming Chen

Keyword(s):

High Speed ◽

Tool Path ◽

Upper Bounds ◽

Interpolation Algorithm ◽

Sharp Corner ◽

Machining Dynamics ◽

Linear Distance ◽

Smooth Motion ◽

Optimal Feed ◽

Five Axis

To alleviate the feed fluctuation and maintain a smooth feed in five-axis machining, this paper takes the following two constraints into account: (1) the machining dynamics, including the constraints of power, velocity and acceleration represented by upper bounds for each axis (2) the contour constraints of the tool path, including the linear distance of the segment and sharp corner at the segment junctions. With the analysis of these constraints, the optimal feed is derived and the corresponding adjusted interpolation algorithm is presented such that a smooth motion during the machining can be obtained. The presented algorithm is demonstrated by the simulation result.

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An Optimal Feed Interpolation with Jerk-Limited Acceleration for Five-Axis Grinding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.359-360.204 ◽

2007 ◽

Vol 359-360 ◽

pp. 204-209

Author(s):

Jing Chun Feng ◽

Yu Hao Li ◽

Yu Han Wang ◽

Ming Chen

Keyword(s):

Upper Bounds ◽

Interpolation Algorithm ◽

Sharp Corner ◽

Machining Dynamics ◽

Linear Distance ◽

Smooth Motion ◽

Optimal Feed ◽

Five Axis

To overcome the acceleration discontinuity and feed fluctuation of the conventional five-axis grinding interpolator, a jerk-limited acceleration is utilized and two aspects of constraints is taken into account: (1) the machining dynamics, including the constraints of power, velocity, acceleration and jerk represented by upper bounds for each axis (2) the contour constraints of linear segments, including the linear distance of the segment and sharp corner at the segment junctions. With the analysis of these constrains, the optimal feed for each segment and the joint feed at the segment junctions is derived. The corresponding adjusted interpolation algorithm with jerk-limited acceleration is presented such that a smooth motion during the machining can be maintained. The presented algorithm is demonstrated by the simulation result.

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