Shape Factor Effects in Material Selection: Humanpowered-Plane Spars
· The diagram shows two spars in a human-powered plane. The tailplane is on a spar cantilevered from the cockpit area, and the wing-spars define the wing structure. Both these components must be resistant to bending and torsional deflection if the aerodynamic integrity of the plane is to be preserved.
· The shape independent performance index required is (E/ρ2), as minimizing bending is the goal. Candidate materials are wood (spruce), aluminum alloy tubing, and carbon fiber reinforced polymer (CFRP).