Reduction of Bending Moment at the Root of a Rotor Blade: Effects of Replacing Elastic Beam‐type Flapping Hinge by Leaf Springs

It is shown that a reduction of the bending moments in a helicopter rotor blade may be achieved by replacing an elastic beam‐type flapping hinge by a stack of leaf‐springs having the same overall bending stiffness but no shear stiffness. This reduction becomes more pronounced when the tensile load on the flapping hinge is increased.