VIBRATION CHARACTERISTICS OF THERMALLY CYCLED GRAPHENE NANOPLATELET (GNP) REINFORCED 3D-FIBER METAL LAMINATES (3D-FML)

Abstract

Harsh environmental conditions may cause materials to degrade and eventually fail, or even worse, it can be coupled with undesirable vibrations in mechanical systems, resulting in premature failure of the system. Such combined loading scenarios are often encountered by transport vehicles (i.e., airplane cabins, and train and automobile components). Today, fiber metal laminates (FMLs) and sandwich composites are often used in the fabrication of various components of transport vehicles. Therefore, it is of paramount importance to study the static and dynamic characteristics of such materials under combined loading scenarios and ensure their durability and safety. A recently introduced class of 3D fiber metal laminate (3D-FML) in our research group has shown exemplary mechanical response characteristics; however, the vibration characteristic of this novel hybrid material system under harsh environmental conditions has not been studied. Therefore, exploring the effect of environmental parameters on the frequency response of this class of materials shapes the main objective of this research. Specifically, the main goals of this research are to characterize and understand the frequency response of 3D-FMLs under thermal fatigue and attempt to improve their vibration response by incorporation of an effective solution. To do so, 3D-FMLs specimens are exposed to combined thermal and humidity cycles. Subsequently, the vibration characteristics of the system are experimentally evaluated. An attempt is also made to improve the damping characteristics of the material system by incorporation of graphene nanoplatelet within the interface layers of the hybrid system. It is also demonstrated that recently developed nondestructive techniques can be effectively used to assess the influence of environmental conditions on the static and dynamic behavior of 3D-FMLs and evaluate their potential degradation under thermal fatigue.