Masters Theses

Keywords and Phrases

Abrasive waterjet cutting; Box-Behnken design; Graphite/Epoxy composite; Response surface methodology; Surface roughness; Ra


"In the present work, surface roughness after machining of composite material was the main focus of study. Response surface methodology with Box- Behnken experimental design was applied in predicting the surface roughness (Ra) of abrasive waterjet cut 1-inch-thick graphite/epoxy composite. Second order response equations for Ra were generated with minitab, a statistical software as a function of pressure, traverse speed and isolated abrasive mesh size. Influence of each of these factors on the response were analyzed with 3D response surface plots. Abrasive mesh size was also found be a factor influencing Ra along with traverse speed and pressure. Using 80 HPX Barton garnet in the linear cuts, model equations were generated including abrasive flow rate as a factor. The model equations were well verified with experimental data. As a result, these response equations would be able to predict Ra values within the range of input parameters without actually performing the experiments. Stacking of 1/4" thick composites was done and compared with 1" thick material in terms of Ra. With abrasive size as focus, particle size distribution of Barton garnet was analyzed before and after entering the cutting head. A large fragmentation of the garnet occurred during acceleration in mixing tube and focusing tube. Over 50-60% of the garnet was less than the size of screen #100 mesh size. Pressure has significant influence on abrasive disintegration rather than abrasive flow rate. GMA Australian garnet, Wesjet garnet and Barton garnet were compared for particle size distribution after sieving"--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


Missouri University of Science and Technology

Publication Date

Summer 2016


xi, 109 pages

Note about bibliography

Includes bibliographical references (pages 106-108).


© 2016 Prabhakar Bala, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Water jet cutting
Surface roughness
Graphite composites
Response surfaces (Statistics)
Experimental design

Thesis Number

T 10946

Electronic OCLC #


Included in

Manufacturing Commons