A structural element for use in aerospace applications such as a structural element suitable as an aircraft component is described. In one embodiment of the invention, the composite structure comprises: (a) at least one member having an inner surface and an outer surface; (b) a rib having a first end and a second end; (c) a rib-receiving member integral to the inner surface of the at least one member, wherein the rib-receiving member comprises a plurality of rib-receiving elements and openings therein for receiving the first end of the rib and at least one cover sheet having an opening therein for receiving the first end of the rib; and (d) at least one anchoring element interconnecting the rib-receiving elements. In another embodiment of the invention, the composite structure comprises: (a) at least one member having an inner surface and an outer surface; (b) a rib having a first end and a second end; and (c) a rib-receiving member integral to the inner surface of the at least one member, wherein the rib-receiving member comprises a rib-receiving sleeve having an open end for receiving the rib and a closed end, and two sleeve support members, wherein the sleeve support members are disposed on opposite sides of the sleeve and interconnect the sleeve to the inner face of the at least one member.