Investigation of Drilling Parameters Using Grey Relational Analysis and Response Surface Methodology of Biaxial Glass Fibre Reinforced with Modified Epoxy Resin Composite

Table 3

ANOVA analysis for surface roughness.

Analysis of variance
Source	DF	Seq SS	Contribution	Adj SS	Adj MS	value	value
Model	13	247.686	95.33%	247.686	19.053	50.3	0
Linear	4	159.384	61.35%	163.418	40.855	107.86	0
Drill bit	1	142.891	55%	140.711	140.711	371.47	0
Feed	1	2.901	1.12%	4.785	4.785	12.63	0.001
Speed	1	12.277	4.73%	14.827	14.827	39.14	0
Square	3	30.065	11.57%	28.381	9.46	24.97	0
Drill bit  drill bit	1	22.863	8.80%	10.112	10.112	26.69	0
Feed  feed	1	6.474	2.49%	10.199	10.199	26.92	0
2-way interaction	6	58.237	22.42%	58.237	9.706	25.62	0
Thickness  drill bit	1	44.192	17.01%	50.761	50.761	134.01	0
Thickness  feed	1	10.067	3.87%	10.476	10.476	27.66	0
Drill bit  speed	1	2.308	0.89%	2.322	2.322	6.13	0.019
Error	32	12.121	4.67%	12.121	0.379
Total	45	259.808	100.00%
S	R-sq	R-sq (adj)	PRESS	R-sq (pred)
0.615460	95.33%	93.44%	24.3310	90.63%