Statistical assessment of natural frequency values obtained from numerical analyses in the tapered composite laminated beams

Abstract

In the last years, the glass/epoxy laminated composites which are a combination of glass reinforcement and epoxy matrix are widely used in the field of automotive and aerospace due to their strength/weight ratio. The proposed study statistically evaluates the natural frequency data obtained by the numerical analysis of glass reinforced epoxy matrix beams with Taguchi method. Accordingly, numerical analyzes were performed based on L27 orthogonal array at different levels of tapered angle (0, 0.25, and 0.5), fiber orientation angle (30?, 600?, and 900?), and a/l ratio (delamination ratio) (0, 0.25, and 0.5). The obtained results were evaluated with analysis of variance (ANOVA), regression analysis, main effects, and interactions plots. Lastly, it was observed that the tapered angle changes directly with the natural frequency and inversely with a/l delamination rate, and there is a dramatic increase in the natural frequency at the 30? angle. With regression analysis, the effects of main, interaction, and squares of factors on natural frequency are predicted with a coefficient of determination of 95.63%. Finally, the optimum natural frequency is obtained at third level of the tapered angle (A = 0,5), the first level of angle (B = 30?) and a/l ratio (C = 0) as 40.091 Hz.