The present disclosure is directed to a rotor blade that includes a shell defining an interior cavity. The rotor blade also includes exterior surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge. Each of the pressure side, the suction side, the leading edge, and the trailing edge extends between a tip and a root. The shell defines a span and a chord. A shear web is positioned in the interior cavity and coupled to the shell. The shear web includes a lattice structure.