Masters Theses


"Graphite-epoxy composites are being widely used in many aerospace and structural applications because of their properties: which include lighter weight, higher strength to weight ratio and a greater flexibility in design. However, the inherent anisotropy of these composites makes it difficult to machine them using conventional methods. To overcome the major issues that develop with conventional machining such as fiber pull out, delamination, heat generation and high tooling costs, an effort is herein made to study abrasive waterjet machining of composites. An abrasive waterjet is used to cut 1" thick graphite epoxy composites based on baseline data obtained from the cutting of 1/4" thick material. The objective of this project is to study the surface roughness of the cut surface with a focus on demonstrating the benefits of using higher pressures for cutting composites. The effects of major cutting parameters: jet pressure, traverse speed, abrasive feed rate and cutting head size are studied at different levels. Statistical analysis of the experimental data provides an understanding of the effect of the process parameters on surface roughness. Additionally, the effect of these parameters on the taper angle of the cut is studied. The data is analyzed to obtain a set of process parameters that optimize the cutting of 1" thick graphite-epoxy composite. The statistical analysis is used to validate the experimental data. Costs involved in the cutting process are investigated in term of abrasive consumed to better understand and illustrate the practical benefits of using higher pressures. It is demonstrated that, as pressure increased, ultra-high pressure waterjets produced a better surface quality at a faster traverse rate with lower costs"--Abstract, page iii.


Galecki, Greg

Committee Member(s)

Summers, David A.
Liou, Frank W.


Mechanical and Aerospace Engineering

Degree Name

M.S. in Manufacturing Engineering


Missouri University of Science and Technology. Center for Aerospace Manufacturing Technologies
KMT Waterjet Systems Inc.
Boeing Company


Missouri University of Science and Technology

Publication Date



viii, 111 pages

Note about bibliography

Includes bibliographical references (pages 106-110).


© 2014 Aiswarya Choppali, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Water jet cutting
Graphite composites
Surface roughness

Thesis Number

T 10932

Print OCLC #


Electronic OCLC #


Included in

Manufacturing Commons