Bending of composite sandwich beams with metal facesheets

Abstract

This study investigates the bending behaviour of sandwich structures via the application of the three-point bending test. The specimens were composed of Unifoam Polystyrene foam core sandwiched between two aluminium face sheets. Numerical analysis was carried out via the use of Finite Element Software, ANSYS. Experimental data from previous study was carefully analysed and compared with the results of the numerical study to validate the finite element model. Different finite element models were explored to find the optimal model to be used. Four Specimens of different layout and dimensions were modelled and subjected to finite element analysis. Two core only specimens were used as validation test as previous studies had been done on the same materials, and this allowed the comparison between numerical and experimental results. Two other specimens were sandwich structures with the same core and facesheets materials but different core thickness. Results showed that specimens with facesheets had higher flexural stiffness and with increasing core thickness led to an increase in force reaction. Experimental results from previous studies shows significantly more core indentation in a thicker core specimen as compared to more bending stress in thinner cores. This phenomenon was not captured in the main finite element models in this study. However additional models using different material properties did observe significant core indentation. Overall, the study provided an insight into the bending behaviours of sandwich structure and the benefits of finite element modelling and analysis.