0
Research Papers

A Model for Bending, Torsional, and Axial Vibrations of Micro- and Macro-Drills Including Actual Drill Geometry—Part II: Model Validation and Application

[+] Author and Article Information
Sinan Filiz

Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213

O. Burak Ozdoganlar1

Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213ozdoganlar@cmu.edu

1

Corresponding author.

J. Manuf. Sci. Eng 132(4), 041018 (Aug 06, 2010) (10 pages) doi:10.1115/1.4001721 History: Received June 22, 2009; Revised April 28, 2010; Published August 06, 2010; Online August 06, 2010

In Part II of this work, an experimental study is conducted to validate the three-dimensional (3D-ST) drill dynamics model. Modal experiments on macro- and micro-drills are performed by exciting the drills with small piezoelectric elements directly attached to the drill body. The response measurements are conducted in a noncontact manner using a laser Doppler vibrometer system. In addition, to perform the comparison on a complete frequency response function, rather than on only natural frequencies and mode shapes, an impact hammer test with a miniature hammer and a small accelerometer was conducted on one of the macro-drills. In the validation study, five macro-drills and three micro-drills with different geometric parameters are used. It was concluded that the 3D-ST model can capture both bending and torsional-axial natural frequencies and mode shapes of macro-drills (up to 15 kHz) and micro-drills (up to 90 kHz) with better than 4.5% accuracy, and with an average absolute error of 1.5%. For each case, the natural frequencies are also compared with those from detailed solid-element finite-elements (FEs) model to gain further insight about the 3D-ST model. The natural frequencies from the FE and 3D-ST models are seen to match with better than 1.5% accuracy. Subsequently, the effects of tool geometry (diameter, aspect ratio, helix angle, and web-taper) and axial (thrust) force on dynamics of macro- and micro-drills are analyzed.

Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Experimental setup for piezoelectric element/laser Doppler vibrometer tests: (a) the laser Doppler vibrometer coupled with a microscope, and (b) the measurement area

Grahic Jump Location
Figure 2

Measurement area of the piezoelectric element/laser Doppler vibrometer setup for the micro-drills

Grahic Jump Location
Figure 3

Cross sections of the drill slices for (ad) 6.27 mm regular helix drill (D2), and (eh) 6.27 mm low helix drill (D3)

Grahic Jump Location
Figure 4

SEM images of the micro-drill cross sections at the tip for (a) MD1 and (b) MD3, and (c) the side image of MD1

Grahic Jump Location
Figure 5

FRF amplitudes for the D1-drill from the impact hammer/accelerometer tests (solid line), and from the 3D-ST model (dashed line)

Grahic Jump Location
Figure 6

Frequency response function for the D2-drill from the piezoelectric element/LDV tests

Grahic Jump Location
Figure 7

Mode-shapes for the D2-drill: (a) first bending mode, (b) second bending mode, (c) first torsional-axial mode, and (d) third bending mode

Grahic Jump Location
Figure 8

Three-dimensional mode-shapes of a macro-drill: (a) first bending mode, (b) second bending mode, (c) first torsional-axial mode, and (d) second torsional-axial mode

Grahic Jump Location
Figure 9

(a) FRF for the D3-drill, (b) first bending mode-shape, (c) second bending mode-shape, (d) first torsional-axial mode-shape, and (e) third bending mode-shape. Solid lines represent the model-predicted mode-shapes and triangles represent the experimental mode-shapes.

Grahic Jump Location
Figure 10

Experimentally obtained FRF magnitude for the MD1-drill

Grahic Jump Location
Figure 11

Mode-shapes for the MD1-micro-drill. Solid lines represent the model-prediction, triangles represent the experimental mode-shapes, and dotted lines represent the mode-shape from the FEM solution. (a) First bending mode, (b) second bending mode, (c) third bending mode, and (d) first torsional-axial mode. Solid lines represent the model-predicted mode-shapes and triangles represent the experimental mode-shapes.

Grahic Jump Location
Figure 12

Change in the natural frequencies for varying fluted section aspect ratio. (a) First natural frequency pair, (b) second natural frequency pair, (c) first torsional-axial mode, and (d) third natural frequency pair.

Grahic Jump Location
Figure 13

Change in the natural frequencies for varying drill diameter. (a) First natural frequency pair, (b) second natural frequency pair, (c) first torsional-axial mode, and (d) third natural frequency pair, for low ((L) for Lt/d=5), medium ((M) for Lt/d=10), high ((H) for Lt/d=15) aspect ratios.

Grahic Jump Location
Figure 14

Change in the natural frequencies for varying helix angle: (a) first natural frequency pair, (b) second natural frequency pair, (c) first torsional-axial mode, and (d) third natural frequency pair. Solid lines are the bending mode pair from the three-dimensional model, dashed lines are the bending mode pair from the one-dimensional model.

Grahic Jump Location
Figure 15

Change in the natural frequencies of the micro-drill for varying tool diameter. (a) First natural frequency pair, (b) second natural frequency pair, (c) third natural frequency pair, and (d) first torsional-axial mode.

Grahic Jump Location
Figure 16

Change in the natural frequencies of the micro-drill for varying aspect ratio. (a) First natural frequency pair, (b) second natural frequency pair, (c) third natural frequency pair, and (d) first torsional-axial mode.

Grahic Jump Location
Figure 17

Change in the natural frequencies of the micro-drill for varying helix angle. (a) First natural frequency pair, (b) second natural frequency pair, (c) third natural frequency pair, and (d) first torsional-axial mode.

Tables

Errata

Discussions

Related

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In