The Effect of Process Damping On Stability and Hole Form in Drilling

Whitehead, Brian T.; Bayly, Philip V.; Calvert, Sean G.

doi:10.4271/2001-01-2605

Cited by 5 publications

(4 citation statements)

References 6 publications

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“…We found that the wavelength dependence of the force was determined by the length of the relief face of the cutter relative to the wavelength of the oscillation: for long relative relief length the maximum force increased with increasing wavelength, for short relative relief length it decreased, and for intermediate relative relief length the dependence was indeterminent. This expands the intuition of Whitehead et al, [1] who used a process damping model that depended inversely on wavelength, as it would for a short tool. Since the wavelength of the oscillation equals the cutting speed divided by the oscillation frequency, this means the damping is proportional to the cutting speed for short tools, and inversely proportional to the cutting speed for long tools.…”

Section: Discussionsupporting

confidence: 63%

“…Tests were performed to determine the frequency response (FRF) of the cutting system, and these FRF were used to parameterize a single degree of freedom model for the cutting process. This model was developed in part by Brian Whitehead, who describes in his thesis [1] an attempt to include friction on the rake face of the tool by incorporating a weighting function that models the variation of forces as the chip slides up the rake face of the tool, after Stépán [5]. One of the parameters of the model is the contact length, L, between the tool relief face and chip.…”

Section: Wavy Surface Force Predictionsmentioning

confidence: 99%

“…The quantitative difference between the three sets of runs concerns the dependence of the maximum force value vs. wavelength of oscillation. In Whitehead [1], a model for process damping due to rubbing on the relief face is proposed that depends inversely on the wavelength of the vibration, based on a suggestion by Tobias [9]. This translates to a term in his linear model that is directly proportional vibration velocity (which depends directly on vibration frequency) and inversely proportional to cutting speed.…”

Section: Crushing Force Simulationsmentioning

confidence: 99%

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Investigations of Nonlinear Forces in Metal Cutting

Stone¹,

Askari²,

Tat³

2006

Computing Letters

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During chatter in metal cutting the tool vibration would cause a variation in "effective" rake angle of the cutter, generating a force variation that depends on penetration rate: a kind of process damping. This effect is examined for forces computed both from a theoretical Merchant-type model, and from a numerical database of forces for metal cutting constructed from a suite of AdvantEdge simulations. Since the tool can potential vibrate at any angle relative to the workpiece, the forces for varying angle of vibration were computed, and the dynamic stability consequences considered. It is found that the two models lead to similar forces for varying vibration angle, at least through first order. Depending on the vibration angle the force will either increase or decrease with both chip load and penetration rate, reflecting the difference in the effect on the chipload and cutting speed with varying vibration direction. Second order terms in penetration rate were different in the two formulations, possibly a result of approximations used in the calculations involved in the Merchant formulation. Dynamically this means that the linear stability of each vibration angle is the similar for the two models, while the differences in nonlinear terms results in differences in the type Hopf bifurcation observed upon loss of stability.

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Section: Discussionsupporting

confidence: 63%

Section: Wavy Surface Force Predictionsmentioning

confidence: 99%

Section: Crushing Force Simulationsmentioning

confidence: 99%

See 1 more Smart Citation

Investigations of Nonlinear Forces in Metal Cutting

Stone¹,

Askari²,

Tat³

2006

Computing Letters

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“…among them, M, C, K are the mass matrix, damping matrix and stiffness matrix of the tap respectively, and they are all second-order matrices. Whitehead [26] and Towfighian [27] mentioned that the vibrations to cause roundness errors are divided into two categories: chatter and low frequency vibration. In tapping process, the speed of the tap is usually low, and the frequency is much lower than the lowest natural frequency of the tool.…”

Section: Introductionmentioning

confidence: 99%

Mathematical Model for Tapping Simulation to Predict Radial Pitch Diameter Difference of threads

Ren

Yan

2021

Preprint

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As the most important component of parts, thread has a great influence on the mechanical properties and service performance of parts. In order to ensure the quality of the thread, the thread quality inspection standard involves 11 main thread characteristics, of which the surface roughness of the thread is the most studied, and the research on Radial Pitch Diameter Difference (RPDD) is still blank. In this paper, a quasi-static model of the tapping process is developed based on the roundness error mechanism of the hole, which includes cutting force and cutting damping force. Due to the regenerative nature of cutting, the force on each cutting edge depends on both the tool’s current position and previous position. According to the eigenvalues and eigenvectors of the discrete state-transition matrix, RPDD is finally determined, and the influence of the chamfer length and the spindle speed on RPDD is simulated by this model. The results demonstrate that the chamfer length and spindle speed will affect RPDD, and the RPDD is the smallest when the chamfer length is 2 threads and the spindle speed is 1400 rev/min. The development of this model not only provides a cheap and effective method for the study of RPDD, but also lays a foundation for further experimental research.

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Tapping simulation to reduce radial pitch diameter difference of threads

Ren

Yan

2022

Int J Adv Manuf Technol

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The Effect of Process Damping On Stability and Hole Form in Drilling

Cited by 5 publications

References 6 publications

Investigations of Nonlinear Forces in Metal Cutting

Investigations of Nonlinear Forces in Metal Cutting

Mathematical Model for Tapping Simulation to Predict Radial Pitch Diameter Difference of threads

Tapping simulation to reduce radial pitch diameter difference of threads

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