Modeling and optimization of mechanical behavior of bonded composite-steel single lap joints by response surface methodology

The curing time and temperature of a paste adhesive were found to be one of the most effective parameters in the behavior of the bonded composite-steel joints. These parameters were utilized in modeling and optimization, using response surface methodology to achieve a good joint strength and a reasonable joint elongation. The central composite second-order rotatable design has been utilized to conduct the experimental matrix planning. Analysis of variance has been employed successfully to test the adequacy, significance and meaningfulness of the developed mathematical model. Numerical analyses indicated the optimized curing temperature and time as 40 °C and 180 min, respectively. The predicted values were verified by mechanical tests, optical microscopy and scanning electron microscopy; thus the developed mathematical models can predict the responses adequately and optimize the key process parameters quickly and precisely.