Question

Calculate the mass (in metric tons) of a blade made of carbon fiber reinforced polymers, M_{blade}^{CFRP}M blade CFRP ​ , setting the stress limit equal to fatigue limit of the material \sigma_0^{CFRP}= 300MPaσ 0 CFRP ​ =300MPa. GIVEN DATA: Length of the blade L=86mL=86m Rated wind speed V_r=11 m/sV r ​ =11m/s Density of air \rho_{air} = 1.2 kg/m^3ρ air ​ =1.2kg/m 3 Acceleration of gravity g= 10 m/s^2g=10m/s 2 Blade height at root section h_0^{flap} = 2mh 0 flap ​ =2m Blade width at root section h_0^{edge} = 4mh 0 edge ​ =4m Data The properties of the three materials to be investigated are given in Table 1. The composite material data is for unidirectional (UD) composites with a fibre volume fraction of 55-60 \%55−60% . The carbon fibre composite data is for a low cost carbon fibre. The provided data for fatigue limits corresponds to approximately 10^8 -10^910 8 −10 9 cycles. Material Density (\rhoρ) Stiffness Strength Fatigue limit Aluminium 2700 kg/m^32700kg/m 3 70 GPa70GPa 300 MPa300MPa 150 MPa150MPa UD glass fibre composite 1900 kg/m^31900kg/m 3 44 GPa44GPa 1000 MPa1000MPa 180 MPa180MPa UD carbon fibre composite 1600 kg/m^31600kg/m 3 120 GPa120GPa 2000 MPa2000MPa 300 MPa300MPa Table 1. Properties of three materials

Answer 1

Answer:

Calculate the mass of the blade