Modelling and optimisation of adhesive bonded joint strength of composites for aerospace applications

In recent past, adhesive bonding gain much attention world-wide in joining of engineered parts namely, automotive and aerospace structures. The strength of adhesive bonded composite joints is studied by conducting experiments based on the matrices of central composite design. The collected data was analysed using response surface methodology. The mathematical model was established to express the load carrying capacity and joint strength as a function of input variables. Further, analysis of variance was carried out to ensure good fit to the experimental data. Moreover, the statistical methods determine significant interaction effects among the factors. Finally, genetic algorithm was used to locate the optimum points of joint strength for the set of inputs, i.e., 40 mm overlap length, 0.2 mm adhesive thickness and 4.526 μm surface roughness. The results showed that adhesively bonded single lap joints strength was influenced by overlap length (8%), adhesive thickness (78.56%), and surface roughness (1.43%). Statistical experimental design techniques were found to be useful in understanding the complex relationships seen in the data, and also in interpreting the results.