A shell element that is well suited for the analysis of folded plate and shell structures is presented. In contrast to unfolded plates, the walls of folded plates can undergo substantial amount of transverse as well as membrane bending. For instance, in a rotor blade, the flange and web of a spar undergo transverse and membrane bending under flap bending, respectively, and the reverse occurs under lag bending. Therefore, a suitable shell-element technology should accurately model the transverse-bending and membrane-bending deformations, while maintaining kinematic compatibility along the element edges. The new shell element incorporates the Assumed Natural DEviatoric Strain (ANDES) and anisoparametric element formulations. The element robustness is established by comparisons with experimental measurements and other numerical predictions.