Application of integrated soft computing techniques for optimisation of hybrid CO2 laser–MIG welding process

•Three soft computing based integrated models such as, ANN–GA, ANN–SA and ANN–Quasi Newton have been developed.•Those models predicted and optimised welding strength during hybrid CO2 laser–MIG welding process.•Best ANN architecture (3-11-1 network) predicts welding strength with mean absolute percentage errors less than 2%.•ANN–GA shows best optimisation performance with only 0.09% experimental validation error.•Welding speed shows maximum influence on welding strength and an increase in welding speed decreases welding strength.

In this paper, artificial neural networks (ANNs), genetic algorithm (GA), simulated annealing (SA) and Quasi Newton line search techniques have been combined to develop three integrated soft computing based models such as ANN–GA, ANN–SA and ANN–Quasi Newton for prediction modelling and optimisation of welding strength for hybrid CO2 laser–MIG welded joints of aluminium alloy. Experimental dataset employed for the purpose has been generated through full factorial experimental design. Laser power, welding speeds and wires feed rate are considered as controllable input parameters. These soft computing models employ a trained ANN for calculation of objective function value and thereby eliminate the need of closed form objective function. Among 11 tested networks, the ANN with best prediction performance produces maximum percentage error of only 3.21%. During optimisation ANN–GA is found to show best performance with absolute percentage error of only 0.09% during experimental validation. Low value of percentage error indicates efficacy of models. Welding speed has been found as most influencing factor for welding strength.

Graphical abstractThree integrated ANN–GA, ANN–SA and ANN–Quasi Newton methodology has been developed and implemented according to the following way to determine optimised input parameter setting for maximum welding strength during laser–MIG hybrid welding of aluminium alloy plates. Finally, significance of optimised parameters has been determined by ANOVA. Variation of welding strength with individual process parameters have been tested through main effect plots and interaction plots.Figure optionsDownload full-size imageDownload as PowerPoint slide