Influence of graphene fillers on vibration characteristics of tapered hybrid GFRP composite beams under elevated temperature condition: Numerical and experimental study

In this study, numerically and experimentally the dynamic characteristics of graphene-reinforced glass fiber–reinforced polymer hybrid uniform and thickness tapered laminated composite beams were investigated. First, the graphene-epoxy nanocomposite solution without and with 0.25, 0.50, and 0.75 wt.% of graphene reinforcement is prepared by the heat shearing technique and then used for the fabrication of glass fiber–reinforced polymer hybrid uniform and thickness tapered composite beams using the hand lay-up method. The elastic properties of the hybrid beams were evaluated using the impulse excitation of vibration technique (ASTM E1876-15) under elevated temperature. Further, the numerical and experimental modal analysis of the hybrid beams with uniform and tapered configurations were conducted with variation in wt.% of graphene particles under fixed-fixed and fixed–free end supports. The results reveal that the natural frequencies of the glass fiber–reinforced polymer hybrid uniform and tapered configurations with 0.25 wt.% of graphene are greater than those of the glass fiber–reinforced polymer beams without graphene reinforcement and observed lesser for 0.5 and 0.75 wt.% of graphene under fixed-fixed and fixed-free end supports, respectively, due to unavoidable agglomeration effects. Furthermore, the parametric study was performed with the influence of weight fraction of graphene and temperature on the transverse response of the tapered composite beam. Hence, it can be concluded that the use of graphene filler in the glass fiber–reinforced polymer composites in the tapered composite beams improves the bending natural frequencies significantly when the weight fraction of the graphene is used lesser as agglomeration is unavoidable in practical condition. Therefore, the comprehensive numerical and experimental work presented in this study will be useful to the designers while using graphene fillers to improve the bending characteristics of the tapered composite beams.