Abstract: A layout and manufacturing method for fiber-reinforced, laminated composite shells utilizes as a reinforcement a nested assembly of braided sleeves. The original sleeve diameters are selected individually such that, upon being deformed into the final shape, the fibers acquire angular orientations prescribed by the shell design. Shells of desired shapes are obtained either by pulling the sleeves on a rigid mandrel or, alternately, by statically defoming the nested sleeve assembly, thereby eliminating the use of mandrels. The statical means involve proper combinations of tensile edge forces and surface loads exerted, e.g., by a pressurized bladder or by spinning the assembly. In one embodiment, the sleeves are tensioned and, if necessary, vibrated prior to matrix curing so as to force the fibers to approach geodesic trajectories (isotensoid layout). By releasing the sleeve tension after curing, a favorable compressive prestress is induced in the matrix material.

Abstract: Disclosed is a structure of flexible tensile members which requires only two arrays of said members for obtaining lateral stiffness of said structure, the ends of each member being attached to contour elements and the members of each array having opposite curvatures for forming an axisymmetric geodesic network which is a section of a surface of revolution. The members of both arrays are prestressed and said network is geometrically arranged to be torque-balanced within said contour elements.