Dynamic and Buckling Analysis of Hybrid Composite Beam Strengthened with Carbon Fibers/Aramid Fibers under Temperature Gradient

Abstract

Dynamic and buckling of a composite beam reinforced with a combination of carbon and aramid fibers is studied in this paper. The beam is under a thermal gradient through the thickness. Timoshenko beam is made of a polymer matrix (epoxy resin) reinforced with layers of high–strength carbon and high-toughness aramid fibers in order to create a balance between stiffness and toughness and create a type of structural composite beam with excellent strength and toughness. The mechanical and thermal properties of the hybrid composite beams are obtained based on the mixed law method. The equations of motion are extracted based on the Hamilton principle and then solved by the generalized differential quadrature method (GDQ). In this study, a thermal gradient is applied to the beam and then the vibration and buckling response of this hybrid composite beam are studied. The main contribution of this paper is the vibration and buckling responses of a hybrid composite structure strengthened by carbon and aramid fibers. The effect of the hybrid ratio as well as the stacking sequence on the free vibrations and critical buckling load are presented. The fundamental frequency and critical buckling load are largely affected by the stacking sequence. The conclusions show that the use of aramid fibers in the composite beam reinforced with carbon fibers decreases the natural frequency as well as the critical buckling load of the beam. The conclusions also show that for the symmetric hybrid composite beam, despite the critical buckling temperature being the same, the critical buckling load is different and depends on the location of the fibers.

Keywords

• carbon fiber
• aramid fiber
• hybrid ratio
• buckling load
• vibration