Effect of Elevated Temperature on Harmonic Interlaminar Shear Stress in Graphite/Epoxy FRP Simply Supported Laminated Thin Plate Using Finite Element Modeling

Graphite/Epoxy Fiber Reinforced Polymer (FRP) plates are used widely due to their high strength to weight ratio. Current work is concerned about investigating the harmonic interlaminar shear stresses existing between laminates in a simply supported composite Graphite/Epoxy FRP plate under elevated temperatures and for different fiber orientation schemes using finite element modeling. Interlaminar shear stress which is affected by temperature plays a major role in composite material delamination. The simply supported composite plate under study consists of eight laminated layers with different orientation schemes ([0°]8, [0°/15°]4, [0°/30°]4, [0°/45°]4, [0°/60°]4, [0°/75°]4, and [0°/90°]4). Modal analysis is performed to find the natural frequencies for all fiber orientations and temperatures considered. However, harmonic analysis is carried out to study the transverse deflection and interlaminar dynamic shear stress for orientation schemes and temperatures considered at the interfacial of the 7th ply. It is found that increasing temperature leads to slight drop in natural frequency at each orientation scheme but leads to higher deflection and shear stress. Furthermore, it is observed that orientation scheme [0o/45o]4 is the best case for all the temperatures considered since minimum transverse deflection and interfacial shear stress are obtained for almost all the driving frequency range.