Mathematical Modelling of a Friction Stir Welding Process to Predict the Joint Strength of Two Dissimilar Aluminium Alloys Using Experimental Data and Genetic Programming

Table 6

Comparison between experimental and predicted values of impact strength at = 99.4.

0; (°)	1; (KN)	2; (rpm)	3; (mm/s)	4; (mm)	Impact strength (J/m^2)		Error	Linear regression	Error
					Experimental	GP
3	2	600	115	3	0.62	0.627465	−0.007465129	0.130185	0.489815
3	2.5	600	115	3	0.56	0.56651	−0.006510201	−0.05781	0.617815
3	3	900	75	3	0.89	0.888732	0.001268461	−0.21518	1.105175
3	3	900	90	3	0.95	0.956007	−0.006007421	−0.21339	1.16339
3	3	1200	75	3	0.9	0.90866	−0.008660352	−0.17978	1.079775
3	3	1200	90	3	0.89	0.890057		−0.17799	1.06799
4	2	600	115	3	0.89	0.890585	−0.000584826	0.133285	0.756715
4	2	900	75	3	0.88	0.876978	0.003022139	0.163925	0.716075
4	2	900	115	3	0.9	0.898867	0.001133347	0.168685	0.731315
4	2	1200	90	3	0.81	0.810876	−0.000875952	0.20111	0.60889
4	2.5	900	75	3	0.95	0.956236	−0.006236064	−0.02408	0.974075
4	2.5	900	115	3	0.89	0.880833	0.009166732	−0.01932	0.909315
4	2.5	1200	90	3	0.91	0.912273	−0.002273049	0.01311	0.89689
4	3	600	90	3	0.718	0.716218	0.001782065	−0.24569	0.96369
4	3	900	75	3	0.73	0.724777	0.005222838	−0.21208	0.942075
4	3	900	90	3	0.745	0.739808	0.005191798	−0.21029	0.95529
4	3	1200	75	3	0.72	0.715923	0.004076512	−0.17668	0.896675
4	3	1200	90	3	0.71	0.713943	−0.003943005	−0.17489	0.88489
4	3	1200	115	3	0.72	0.727521	−0.007521241	−0.17192	0.891915
3	2	600	90	4	0.8	0.799481	0.000518906	0.08501	0.71499
3	2.5	600	90	4	0.63	0.630611	−0.00061142	−0.10299	0.73299
3	2.5	600	115	4	0.58	0.575422	0.00457819	−0.10002	0.680015
3	3	900	90	4	0.91	0.918671	−0.008671191	−0.25559	1.16559
3	3	1200	75	3	0.9	0.90866	−0.008660352	−0.17978	1.079775
3	3	1200	90	3	0.89	0.890057		−0.17799	1.06799
4	2	600	75	4	0.65	0.651921	−0.001920617	0.086325	0.563675
4	2	600	115	3	0.89	0.890585	−0.000584826	0.133285	0.756715
4	2	600	115	5	0.82	0.813068	0.006931789	0.048885	0.771115
4	2	900	75	3	0.88	0.876978	0.003022139	0.163925	0.716075
4	2	900	115	3	0.9	0.898867	0.001133347	0.168685	0.731315
4	2	900	115	5	0.865	0.865083		0.084285	0.780715
4	2	1200	75	5	0.71	0.712427	−0.002426603	0.114925	0.595075
4	2	1200	90	3	0.81	0.810876	−0.000875952	0.20111	0.60889
4	2	1200	90	5	0.77	0.777844	−0.007843952	0.11671	0.65329
4	2	1200	115	4	0.78	0.78315	−0.003149838	0.161885	0.618115
4	2.5	600	90	4	0.86	0.860959	−0.000958576	−0.09989	0.95989
4	2.5	1200	75	4	0.8	0.808779	−0.008778763	−0.03088	0.830875
4	2.5	1200	90	4	0.93	0.931005	−0.001005299	−0.02909	0.95909
4	3	600	75	4	0.72	0.717328	0.002671809	−0.28968	1.009675
4	3	900	75	4	0.74	0.737732	0.002268126	−0.25428	0.994275
4	3	1200	75	4	0.725	0.715911	0.009089208	−0.21888	0.943875
4	3	1200	90	4	0.718	0.713928	0.004072254	−0.21709	0.93509
3	2	600	90	4	0.8	0.799481	0.000518906	0.08501	0.71499
3	2.5	600	90	4	0.63	0.630611	−0.00061142	−0.10299	0.73299
3	2.5	600	115	4	0.58	0.575422	0.00457819	−0.10002	0.680015
3	3	900	90	4	0.91	0.918671	−0.008671191	−0.25559	1.16559
3	3	1200	75	3	0.9	0.90866	−0.008660352	−0.17978	1.079775
3	3	1200	90	3	0.89	0.890057		−0.17799	1.06799
4	2	600	75	4	0.65	0.651921	−0.001920617	0.086325	0.563675
4	2	600	115	3	0.89	0.890585	−0.000584826	0.133285	0.756715
4	2	600	115	5	0.82	0.813068	0.006931789	0.048885	0.771115
4	2	900	75	3	0.88	0.876978	0.003022139	0.163925	0.716075
4	2	900	115	3	0.9	0.898867	0.001133347	0.168685	0.731315
4	2	900	115	5	0.865	0.865083		0.084285	0.780715
4	2	1200	75	5	0.71	0.712427	−0.002426603	0.114925	0.595075
4	2	1200	90	3	0.81	0.810876	−0.000875952	0.20111	0.60889
4	2	1200	90	5	0.77	0.777844	−0.007843952	0.11671	0.65329
4	2	1200	115	4	0.78	0.78315	−0.003149838	0.161885	0.618115
4	2.5	600	90	4	0.86	0.860959	−0.000958576	−0.09989	0.95989
4	2.5	1200	75	4	0.8	0.808779	−0.008778763	−0.03088	0.830875
4	2.5	1200	90	4	0.93	0.931005	−0.001005299	−0.02909	0.95909
4	3	600	75	4	0.72	0.717328	0.002671809	−0.28968	1.009675
4	3	900	75	4	0.74	0.737732	0.002268126	−0.25428	0.994275
4	3	1200	90	4	0.718	0.713928	0.004072254	−0.21709	0.93509