In this numerical and statistical study, lift and drag coefficient performances of NACA-0009 and NACA-4415 airfoils were evaluated in accordance with various attack angle at constant velocity of wind. Lift and drag coefficients of airfoils was numerically determined by computational fluid dynamics code ANSYS FLUENT. Analysis design of numerical calculations was implemented using L16 orthogonal array based on Taguchi method. Angles of attack and airfoil types were considered as control factors. The optimum level and effect of each control factor on responses was statistically implemented using analyses of Signal-to-Noise ratio and variance. As a result of this study, maximum lift and minimum drag coefficient were achieved by using NACA4415 airfoil compared to NACA0009 airfoil. The increase of the angle of attack leads to the increase on the lift and drag coefficients for both airfoils.

In this experimental and statistical study, free vibration behavior of laminated composite beams with functionally graded fiber orientation angles was investigated under clamped-free boundary conditions. The beams were manufactured using E-glass/epoxy. Fiber orientation angles of the beams were analyzed based on Taguchi’s L9 (3³) orthogonal array. The effect of fiber orientation angles and beams with optimum levels were assessed using analysis of signal-to-noise ratio. Significant laminates of the beams and their percent contributions on the free vibration responses were obtained using analysis of variance. According to this study, the increase of fiber orientation angle from 0° to 80° causes a decrease in the fundamental frequency behavior of laminated composite beams. The most effective control factors were found to be the first and the second laminates symbolized as L1 with 85.86% contribution, the third and the fourth laminates symbolized as L2 with 12.29% contribution, the fifth and the sixth laminates symbolized as L3 with 1.84% contribution, respectively. This study can be used as a reference for free vibration analysis of cantilever laminated composite beams made of functionally graded fiber orientation angles as experimentally and statistically.

The aim of this numerical and statistical study was to investigate the buckling analysis of laminated composite plates containing functionally graded fiber orientation angles. The laminated composite plates had functionally graded fiber orientation angles based on Taguchi’s L18 (2¹ × 3²) orthogonal array. The fiber orientation angles were considered to be control factors. Numerical analyses were performed using finite element software ANSYS. The optimum critical buckling load and the effects of fiber orientation angles for maximum data were determined using the analysis of the signal-to-noise ratio. The importance levels of laminates and their percent contribution on the buckling characteristics were calculated using analysis of variance. Regression analysis was employed to investigate the effects of control factors on buckling responses mathematically. The effects of laminate stacking sequence, mesh size, element type, mode number, and boundary condition were carried out using laminates with the optimum levels.

In this study, the deflection response of cantilever laminated composite square plates subjected to the weight of itself was analyzed using finite element and Taguchi methods. The plates with 12 plies were made of glass fiber reinforced polymer composites (GFRP). The arrangements and fiber orientation angles of the plies were conducted using Taguchi’s L9 (33) orthogonal array. Each four plies was assumed to be control factor. Fiber orientation angles were varied from 10 to 90 in degree. Plates were modelled using finite element software ANSYS Parametric Design Language. Analysis of signal-to-noise (S/N) ratio was used in order to evaluate the control factors with the optimum levels for minimum deflection response. Analysis of variance was carried out in order to analyze the powerful influential control factors and their percent contributions on responses.

In this study, effect of square cutout and beam widths on eigenvalue buckling analysis of beams is evaluated using finite element and Taguchi methods. ANSYS software is used to perform the finite element analyses and the analyses were conducted Taguchi L9 orthogonal array with three control factors. Each control factor has three levels. The first control factor is considered as position of square cutout whereas the second control factor was assumed as beam widths. The influence of levels of the beam widths and square cutouts on responses is determined using analysis of signal-to-noise ratio whereas variance analysis was operated to notice the effect of each control factor on the buckling behavior of the beams. According to results obtained from the study, the buckling value of the beams increase as the square cutout get closer to the free edge. Increase of the beam widths leads to an increase on buckling result of the beams. The effect of beam width on the buckling analysis is higher than square cutout.

In this numerical study, natural frequency analysis of layered functionally graded beams in the thickness direction under clamped-free boundary condition was investigated using finite element program ANSYS. The layer arrangements were performed according to Taguchi L9 (3*3) orthogonal array. Mechanical properties of the layers made of different volume fractions of Ti-6Al-4V and ZrO2 materials was assumed as control factors. In order to determine the optimum layers and their levels, signal-to-noise (S/N) analysis is used. Significant layers and their percent contributions on the natural frequency are carried out using Analysis of Variance (ANOVA). In addition, the effects of the boundary conditions (B.C.) such as clamped-free (C-F) and clamped-clamped (C-C) and positions of the optimum layers were evaluated. According to results evaluated, maximum natural frequency for first mode were found to be top and bottom layers with metal-rich and middle layer with ceramic-rich. The most effective layers on the responses was obtained as Layer1 with 48.45%, Layer2 with 16.16% and Layer3 with 34.98%. Layer arrangements play important role on the natural first mode frequency.