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 4

Comparison between experimental and predicted values of tensile strength at = 99.5.

0; (°)	1; (KN)	2; (rpm)	3; (mm/s)	4; (mm)	Tensile strength (MPa)		Error	Linear regression	Error
					Experimental	GP
3	2	600	75	4	201.4173	201.4149	0.002396	199.4963	1.92105
3	2	600	90	4	207.5238	206.971	0.552811	199.6827	7.8411
3	2	900	115	4	200.4701	200.8218	−0.35167	204.3825	−3.91235
3	2	1200	115	4	210.9491	211.2845	−0.33536	208.7715	2.17765
3	2.5	600	75	4	212.8087	212.9875	−0.17885	204.0413	8.76745
3	2.5	600	90	4	214.7545	214.4605	0.294006	204.2277	10.5268
3	2.5	900	90	4	226.1082	226.7305	−0.62225	208.6167	17.4915
3	2.5	1200	115	4	221.0869	221.4523	−0.36539	213.3165	7.77045
3	3	600	75	4	208.9469	208.806	0.140945	208.5863	0.36065
3	3	600	115	4	217.343	217.9036	−0.56067	209.0835	8.25955
3	3	900	75	4	229.8519	229.2028	0.649048	212.9753	16.87665
3	3	900	90	4	233.5722	233.628	−0.0558	213.1617	20.4105
3	3	900	90	5	233.9161	233.6219	0.29422	213.2857	20.6304
3	3	900	115	4	242.6929	242.4103	0.282562	213.4725	29.22045
3	3	1200	75	3	227.4726	227.1649	0.307632	217.2403	10.23235
3	3	1200	75	4	227.1322	227.1745	−0.04233	217.3643	9.76795
3	3	1200	75	5	226.8476	227.184	−0.33641	217.4883	9.35935
3	3	1200	115	3	227.9172	227.7119	0.205277	217.7375	10.17975
3	3	1200	115	4	228.1085	227.7122	0.396347	217.8615	10.24705
3	3	1200	115	5	228.2549	227.7125	0.54248	217.9855	10.26945
4	2	600	75	4	197.3443	196.8444	0.499908	198.4663	−1.12195
4	2	600	75	5	197.1878	196.8481	0.339767	198.5903	−1.40245
4	2	600	90	3	212.6613	212.6237	0.037552	198.5287	14.1326
4	2	600	90	4	213.2592	212.7725	0.486725	198.6527	14.6065
4	2	900	75	3	213.7823	213.4791	0.303131	202.7313	11.05105
4	2	900	75	4	213.8493	214.1454	−0.29617	202.8553	10.99405
4	2	900	75	5	214.0453	214.1446	−0.09932	202.9793	11.06605
4	2	900	90	4	227.3222	227.8775	−0.55531	203.0417	24.2805
4	2	900	90	5	227.7843	227.8655	−0.08118	203.1657	24.6186
4	2	900	115	3	226.5605	227.1803	−0.61986	203.2285	23.33205
4	2	900	115	4	226.9803	227.1879	−0.20764	203.3525	23.62785
4	2	900	115	5	227.3916	227.191	0.200684	203.4765	23.91515
4	2	1200	90	3	216.5077	217.1303	−0.62257	207.3067	9.201
4	2	1200	90	4	217.0157	217.0639	−0.04823	207.4307	9.585
4	2	1200	90	5	217.5187	217.2333	0.2854	207.5547	9.964
4	2	1200	115	3	215.5096	215.5605	−0.05092	207.6175	7.89215
4	2	1200	115	4	215.2814	215.5672	−0.28584	207.7415	7.53995
4	2	1200	115	5	215.202	215.5741	−0.37207	207.8655	7.33655
4	2.5	600	75	3	210.9097	211.1155	−0.20586	202.8873	8.02245
4	2.5	600	75	4	210.9576	210.9654	−0.00786	203.0113	7.94635
4	2.5	600	75	5	210.8665	210.847	0.019516	203.1353	7.73125
4	2.5	600	90	4	205.5315	205.905	−0.37355	203.1977	2.3338
4	2.5	600	90	5	206.0258	206.0515	−0.02574	203.3217	2.7041
4	2.5	600	115	3	209.6681	209.8436	−0.17548	203.3845	6.28365
4	2.5	900	75	4	225.0363	224.4874	0.548965	207.4003	17.63605
4	2.5	900	90	4	220.4077	220.5082	−0.10057	207.5867	12.821
4	2.5	900	115	4	227.377	227.1711	0.205856	207.8975	19.47955
4	2.5	1200	75	4	216.1377	216.0029	0.134796	211.7893	4.34845
4	2.5	1200	90	4	215.9696	215.655	0.314621	211.9757	3.9939
4	2.5	1200	115	4	220.2623	219.8801	0.382263	212.2865	7.97585
4	3	600	75	4	204.118	204.1865	−0.06847	207.5563	−3.43825
4	3	600	115	4	217.8454	218.1242	−0.27884	208.0535	9.79195
4	3	900	115	4	238.2042	238.2691	−0.06488	212.4425	25.76175
4	3	1200	75	4	218.2925	218.8536	−0.56111	216.3343	1.95825
3	2	1200	115	5	211.2005	211.2984	−0.09787	208.8955	2.30505
3	2.5	600	75	5	213.5635	213.1032	0.460327	204.1653	9.39825
3	2.5	900	75	5	224.5181	225.1232	−0.60516	208.5543	15.96385
3	2.5	1200	115	5	220.9586	221.4597	−0.50114	213.4405	7.51815
3	3	600	75	5	209.4358	208.8087	0.627182	208.7103	0.72555
3	3	900	75	5	230.5879	230.988	−0.4001	213.0993	17.48865
3	3	900	90	5	233.9161	233.6219	0.29422	213.2857	20.6304
3	3	1200	75	5	226.8476	227.184	−0.33641	217.4883	9.35935
3	3	1200	115	5	228.2549	227.7125	0.54248	217.9855	10.26945
4	2	600	75	5	197.1878	196.8481	0.339767	198.5903	−1.40245
4	2	900	75	5	214.0453	214.1446	−0.09932	202.9793	11.06605
4	2	900	90	5	227.7843	227.8655	−0.08118	203.1657	24.6186
4	2	900	115	5	227.3916	227.191	0.200684	203.4765	23.91515
4	2	1200	90	5	217.5187	217.2333	0.2854	207.5547	9.964
4	2	1200	115	5	215.202	215.5741	−0.37207	207.8655	7.33655
4	2.5	600	75	5	210.8665	210.847	0.019516	203.1353	7.73125
4	2.5	600	90	5	206.0258	206.0515	−0.02574	203.3217	2.7041
4	2.5	900	75	5	225.7942	225.9323	−0.13811	207.5243	18.26995
4	2.5	900	90	5	220.4536	220.4198	0.033768	207.7107	12.7429
4	2.5	900	115	5	228.0017	228.3694	−0.36765	208.0215	19.98025
4	2.5	1200	75	5	216.5734	216.9923	−0.41885	211.9133	4.66015
4	2.5	1200	90	5	216.3825	215.9084	0.474014	212.0997	4.2828
4	2.5	1200	115	5	220.4091	219.8816	0.527542	212.4105	7.99865
4	3	600	75	5	204.4071	204.1895	0.217575	207.6803	−3.27315
4	3	600	115	5	217.7037	218.1192	−0.4155	208.1775	9.52625
4	3	900	90	5	226.0705	226.6372	−0.56667	212.2557	13.8148
4	3	1200	75	5	219.0428	219.1528	−0.11002	216.4583	2.58455
4	3	1200	90	5	219.528	219.6197	−0.09166	216.6447	2.8833