Effect of Core Material on Random Vibration Behaviour of Foam-based Laminated Sandwich Panels Using a Modified Layerwise Theory

The vibration response of foam-based laminated sandwich panels (FLSP) under random loading has been investigated. A modified layerwise displacement theory has been employed to account for the variable material properties of layers through the thickness. The dynamic behaviour of the FLSP was determined using random input excitation. Various foam materials have been used to investigate the effect of core material on the random vibration behaviours of FLSPs. The influencing random parameters, including mean, standard deviation, variance, and autocorrelation, have been determined for various core materials. A proof-of-concept experimental setup was devised to illustrate the performance and accuracy of the proposed modified layerwise theory in random vibration analysis of FLSPs. It was observed that as the softness of the core material increases, the natural frequency of FLSP decreases. Furthermore, the higher the core stiffness, the higher the response parameters of random vibration response, including mean value, standard deviation, and variance. In addition, the FLSP filled with stiffer core material exhibits a higher signal correlation than softcore material.