An experimental study of GLARE 2/1 and 3/2 tensile behavior using Digital Image Correlation

Fiber Metal Laminates (FMLs) are a type of composite material known for their high specific strength. These laminates are designed, as being lightweight, to offer exceptional resistance and strength. This characteristic makes FMLs widely utilized in the aviation industry and aircraft body construction. In this research, the tensile behavior of GLARE (Glass Laminate Aluminum Reinforced Epoxy) is experimentally investigated. GLARE specimens are made of aluminum 2024-T3 plates with a thickness of 0.8 mm and woven glass fibers (E-glass, 200g/cm2) reinforced epoxy, known as GFRE. The layering arrangement in GLARE 2/1 and 3/2 samples consists of Al/GFRE/Al and Al/GFRE/Al/GFRE/Al, respectively. The approximate thickness of GLARE 2/1 and 3/2 specimens is 2.32 mm and 3.88 mm, respectively. The samples are produced using the hot plate method. First, samples are cured at room temperature for 7.5 hours and then continued the curing process for an additional 6 hours under 40°C temperature and 3-bar pressure. Tensile test samples are prepared in accordance with the ASTM D3039 standard and tested under quasi-static conditions. The Poisson's ratio of the GLARE samples was evaluated in comparison to that of aluminum using Digital Image Correlation (DIC). The results indicated an 8.8% increase in tensile strength for GLARE 3/2 compared to that obtained for GLARE 2/1. Furthermore, the Poisson's ratio for GLARE 2/1 and 3/2, compared to aluminum, exhibited reductions of 17% and 27%, respectively. Additionally, the mechanical properties of the GFRE layer were accurately predicted using the Rule-of-Mixture.