Their strength from their curved, shell-like forms, distributing loads efficiently. Comprising a thin, curved shell, often made of reinforced concrete or steel, shell structures eliminate the need for internal supports.

It serves both as a structural framework and an outer covering. Unlike conventional structures, shell structures are self-supporting, eliminating the need for internal beams, columns, or walls.

Their efficiency arises from the curvature, whether single or double, enabling diverse stress paths and optimal load transmission.