Numerical Studies on the Effect of Core Metal Type and Thickness on the Mechanical Behaviour of Fiber Metal Laminates

Abstract

Fiber Metal Laminates are advanced materials that combine the properties of metals with Fiber Reinforced Plastics to attain enhanced mechanical performance. The desired mechanical properties can be achieved by hybridizing the different FRP and/or Metal layers. The research focuses on numerical studies on the effect of core metal type and its thickness on the tensile and impact behavior of fiber metal laminates. At the beginning of the research, the effect of fiber hybridization is considered to study the low velocity impact behavior of FMLs. In the early stage, two types of FML were modeled: i) GFML is based on GFRP, and ii) HFML is based on CFRP and GFRP. Numerical simulations were performed to predict the behavior of FMLs under low-velocity impact loading. The results of the simulation show that the hybridization of CFRP with GFRP enhances the maximum force but reduces the maximum displacement and energy absorption. Furthermore, studies were carried out to analyze the effect of the GFRP and CFRP layer positioning and their thickness along the thickness of the laminate. When GFRP layers are positioned close to the impact side, fiber hybridization enhances maximum contact force and energy absorption while delaying the onset of damage. The significance of optimal stacking sequences is apparent because hybridization also causes enhanced delamination at the material interfaces. In addition, the effect of the thickness of the core metal layer on the low velocity impact behavior of FMLs was considered. The simulation considers two types of FMLs with thinner and thicker cores. The results show that adding a thicker layer of aluminum to the middle of the laminate enhances energy absorption and reduces permanent displacement due to higher plastic dissipation. Laminates with thicker aluminum cores exhibit superior impact resistance, making them more suitable for impact-prone applications. Initial studies found that the metal layer in the fiber metal laminates plays a dominant role in achieving the desired properties. Hence, the present study focuses on the role of core metal type and its thickness on the tensile, low velocity, and high velocity impact behavior of fiber metal laminates. Aluminum 2024 T3 - GFRP-based FML with a titanium 6Al 4V core layer and Titanium 6Al 4V - GFRP-based FML with an aluminum 2024 T3 core layer are considered