Experimental and statistical investigation of the three-point bending strength of the composite sandwich beams with trapezoidal core

Abstract

This paper aims to evaluate the influence of graphene nanoparticles and the structural configuration of the core as independent variables on the flexural strength of the composite sandwich beams by combining experimental and statistical methods. Composite sandwich beams with trapezoidal cores were fabricated using carbon fiber/epoxy and vacuum infusion process. Central composite design (CCD), a subset of response surface methodology (RSM), was employed to statistically analyze the main effect of three input variables, core height, core angle, and graphene content on the flexural strength of the beams. The flexural properties of the beams were derived using a three-point bending test. The experimental and statistical results indicated that the maximum bending load was increased by increasing the height and angle of the core, and the optimal mixing percentage of graphene and epoxy was 0.2 to 0.3 weight percentage. In addition, the experimental results were compared with the numerical simulation obtained from ABAQUS finite element software and the numerical results were found to be in good agreement with the experimental results.