Impact behavior study of sandwich composites reinforced with metal fiber laminate

The performance of air vehicles can be significantly enhanced by reducing the structural weight of the vehicle and using lightweight and durable materials. Fiber Metal Laminates (FMLs) are composite materials designed and utilized for this application, formed by stacking fiber/epoxy layers between slender metal plates. Honeycomb sandwich panel structures, in contrast, are commonly utilized structural composites across various industries today. They possess many superior properties, such as lightweight, high strength, and energy absorption. Low-velocity impacts typically happen on aircraft during takeoff, landing, or while taxiing at slow speeds, as well as during maintenance and repair when tools or parts might unintentionally fall onto the vehicle's surface. The harm inflicted by these impacts can seriously jeopardize the aircraft's structural integrity and functionality, creating substantial risks that could result in disastrous failures. In this thesis, the mechanical behavior of hybrid honeycomb sandwich panels reinforced with fiber metal laminates, has been studied. The behavior of the hybrid composite with certain size under low-velocity (2 m/s and 4 m/s) impact generated using an impactor with different diameters in spherical geometry. The impact was modeled and analyzed using the finite element method (FEM) under appropriate boundary conditions. The analyses revealed that the highest total deformation and stress occurred at the impact center, where the impact damage was focused, and in many instances, permanent deformation manifested as core collapse at the center. These damages were evenly spread outward from the center. The differences in the damage were noted as impact velocities increased and with impactors of varying diameters.