Finite Element Method and Analytical Studies on Fiber-Metal Laminates under Multiaxial Loadings

Fiber-metal laminates (FMLs) are composites materials that are commonly used in areas such as aircraft industry. They are composed of ductile metal layers with high strength fiber reinforced polymer layers. So far, however, only uniaxial tests have been used to characterize the quasistatic mechanical properties, which cannot reflect the real loading situation of the FML applications. In this work biaxial tensile behavior of FMLs with glass and Kevlar fibers based on aluminum alloy is studied with finite element method simulation. The simulation is run to find the stress-strain relationship for FMLs at the off-axis angles of 0˚ and 45˚ for glass and Kevlar fibers. The “composites layups” are constructed for the 3D FML part. Two different elements C3D8R (8-node linear) and C3D20R (20-node quadratic) are used to carry out the simulation. The results show that C3D20R shows major advantages. Analytical solutions based on the classical laminate theory are obtained to compare with the finite element method (FEM) solutions. The results show good consistency.