Kerf geometry, kerf wall features, and cutting front characteristics of an Abrasive Waterjet (AWJ) machined Graphite/Epoxy (Gr/Ep) laminate were studied. A macroscopic analyses suggests that geometrical features associated with AWJ machining of Gr/Ep laminates are influenced by three macro regions along the cutting depth. The presence of these regions, including initial damage at jet entry, smooth cutting, and rough cutting near the jet exit, depends on the operating conditions. Design of experiments and analysis of variance were used to determine the effect of cutting parameters on kerf characteristics and to develop empirical models for kerf profile and features of the three distinct macroscopic regions. Cutting front analysis revealed that the mechanisms of material removal in AWJ machining of Gr/Ep do not change over the jet penetration depth. In general, high quality uniform cuts may be obtained by minimizing initial damage at the jet entry and by extending the smooth cutting region beyond the laminate thickness through the appropriate choice of cutting parameters.

Issue Section:
Technical Papers
Topics:
Composite materials, Epoxy adhesives, Epoxy resins, Graphite, Machining, Cutting, Laminates, Damage, Experimental design, Geometry, Surface roughness
1.
Byrne, G., and Wunsch, U. E., 1986, “Composite Materials in Manufacturing Engineering, Technical Developments and Application,” NBST, Dublin, Ireland.
2.
Wang
D. H.
,
Ramulu
M.
, and
Wern
C. W.
,
1992
, “
Orthogonal Cutting Characteristics of Graphite/Epoxy Composite Materials
,”
Transactions of NAMRI/SME
, Vol.
XX
, pp.
159
–
165
.
3.
Colligan
K.
,
Ramulu
M.
,
1992
, “
The Effect of Edge Trimming on Composite Surface Plies
,”
Manufacturing Review
, Vol.
5
, No.
4
, pp.
274
–
283
.
4.
Ramulu
M.
,
Faridnia
M.
,
Garbini
J. L.
, and
Jorgensen
J. E.
,
1991
, “
Machining of Graphite/Epoxy Composite Materials with PolyCrystalline Diamond Tools
,”
ASME JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY
, Vol.
113
, No.
4
, pp.
430
–
436
.
5.
Ramulu
M.
,
Wern
C. W.
, and
Garbini
J. L.
,
1993
, “
Effect of Fiber Direction on Surface Roughness Measurements of Machined Graphite/Epoxy Composite
,”
Composite Manufacturing
, Vol.
4
, No.
1
, pp.
39
–
51
.
6.
Konig
W.
,
Wulf
Ch.
,
Grab
P.
, and
Wilershied
H.
,
1985
, “
Machining of Fiber Reinforced Plastics
,”
Annals of the CIRP
, Vol.
34
, No.
2
, pp.
537
–
547
.
7.
Abrate, S., and Walton, D., 1992, “Machining of Composite Materials. Part II: Nontraditional Methods,” Composite Manufacturing, No. 2, pp. 85–94.
8.
Ramulu
M.
, and
Arola
D.
,
1993
, “
Waterjet and Abrasive Waterjet Cutting of Unidirectional Graphite/Epoxy Composite
,”
Composites
, Vol.
24
, No.
4
, pp.
299
–
308
.
9.
Geskin, E. S., Tisminetski, L., Verbitsky, D., Ossikou, V., Scotton, T., and Schmitt, T., 1992, “Investigation of Waterjet Machining of Composites,” Proceedings of the Machining of Composite Materials Symposium, ASM Materials Week, Chicago, Illinois, Nov. 1–5, pp. 81–88.
10.
Ramulu
M.
, and
Arola
D.
,
1994
, “
The Influence of Abrasive Waterjet Cutting Conditions on the Surface Quality of Graphite/Epoxy Laminates
,”
Int. J. of Mach. Tool & Manuf.
, Vol.
34
, No.
3
, pp.
295
–
313
.
11.
Hamatani
G.
, and
Ramulu
M.
,
1990
, “
Machinability of High Temperature Composites by Abrasive Waterjet
,”
ASME JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY
, Vol.
112
, No.
4
, pp.
381
–
386
.
12.
Arola, D., and Ramulu, M., 1993, “Mechanisms of Material Removal in Abrasive Waterjet Machining of Common Aerospace Materials,” presented at 7th US WJTA Conference, Seattle, WA, August, 29–31, pp. 43–64.
13.
Friest, H., Haferkamp, H., Laurinat, A., and Louis, H., 1989, “Abrasive Jet Machining of Ceramic Products,” 5th American WJ Conference, August 29–31, Paper 19, pp. 191–204.
14.
Blickwedel, H., Guo, N. S., Haferkamp, H., and Louis, H., 1991, “Prediction of Abrasive Jet Cutting Performance and Quality,” Proceedings of the 10th International Conference on Jet Cutting Technology, pp. 163–179.
15.
Hashish
M.
,
1989
, “
Characteristics of Surfaces Machined with Abrasive-Waterjets
,”
ASME Bound Volume
, MD-Vol.
16
, pp.
23
–
32
.
16.
Hashish
M.
,
1989
, “
Machining of Advanced Composites with Abrasive-Waterjets
,”
Manufacturing Review
, Vol.
2
, No.
2
, pp.
142
–
150
.
17.
Konig, W., and Wulf, Ch., 1984, “The Influence of the Cutting Parameters on Jet Forces and Geometry of the Kerf,” Proceedings of the 7th International Symposium on Jet Cutting Technology, Ottowa, Canada, June 26–28, pp. 1–13.
18.
Hashish
M.
,
1988
, “
Visualization of the of the Abrasive Waterjet Cutting Process
,”
J. Exp. Mech.
, Vol.
28
, No.
2
, pp.
159
–
169
.
19.
Ross, P., 1988, “Taguchi Techniques for Quality Engineering,” McGraw Hill Publications, pp. 115–131.
This content is only available via PDF.
Copyright © 1996
 by The American Society of Mechanical Engineers
You do not currently have access to this content.