In this article, three small wind turbine blades of different materials were manufactured. Finite element analysis was carried out using finite element software ANSYS 14.5 on modeled blades of National Advisory Committee for Aeronautics 4412 airfoil profile. From finite element analysis, first, two flap-wise natural frequencies and mode shapes of three different blades are obtained. Experimental vibration analysis of manufactured blades was carried out using fast Fourier transform analyzer to find the first two flap-wise natural frequencies. Finally, the results obtained from the finite element analysis and experimental test of three blades are compared. Based on vibration analysis, we found that the natural frequency of glass fiber reinforced plastic blade reinforced with aluminum sheet metal (small) strips increases compared with the remaining blades. An increase in the natural frequency indicates an increase in the stiffness of blade.

Modal analysis is a technique which is used to find natural frequency and mode shape of structure. In wind turbine blade specific weight and specific stiffness ratios must be high so that material selection becomes vital problem. GFRP gives high value of these ratios but some reinforcement of strips of steel wire mesh and aluminum sheet metal in GFRP can improve stiffness of blade without much increase in weight of blade. In this paper three wind blades were manufactured from GFRP, GFRP with steel wire mesh reinforcement and GFRP with Aluminum sheet metal reinforcement and modal analysis was carried out on manufactured blades using finite element analysis (FEA) method by using ANSYS 14.5 software and verification of result by experimental modal analysis by using FFT analyzer. Also we suggest best material for wind turbine rotor blade by comparison based on natural frequencies and weight of blades.