A rotor blade has a chord and a span length perpendicular to the chord. The rotor blade includes a first skin having an inner surface and a first plurality of elements extending from the inner surface. The first plurality of elements are distributed along at least a portion of the span length and inclined with respect to the chord of the rotor blade. A second skin is attached to the first skin so as to form an outer surface of the rotor blade. The second skin has a second plurality of elements extending towards the inner surface of the first skin and engaging with the first plurality of elements to form a plurality of ribs within the rotor blade.