Abstract: A load carrying structure having a selectively rigid or flexible characteristic includes a thermoplastic material (7) having a softening temperature above the operating temperature range of the load carrying structure, and a heating arrangement (8) provided to selectively heat the thermoplastic material to above its softening temperature. During normal operation, the thermoplastic material is in a rigid state and the overall load carrying structure is rigid to the prevailing loads. By activating the heating arrangement to heat the thermoplastic material to at least its softening temperature, the thermoplastic material and therewith the load carrying structure becomes flexible so that it may be deformed to a different configuration by applying a deforming load.

Abstract: A stiff elongated hollow structural member has a double-walled structure in the shape of a tube made of an interior tube which has an annular cross-section and an exterior tube which has a different cross-section, in a concentric arrangement. The interior and exterior tubes bound a hollow space filled with an incompressible liquid. Responsive to pressure increases in the liquid, the exterior tube in the elastic material range is bendingly deformable in the direction of a ring-circular cross-section or to a ring-circular cross-section. This hollow structural member can be used as an adjustable stiffness torsion member such as a vehicle steering shaft. Another disclosed adjustable stiffness hollow structural member includes a flat plate facing a corrugated plate to form a hollow space for the incompressible liquid. Increases in pressure of the liquid forces the corrugated member to a more flattened configuration.

Abstract: A woven fabric structure impregnated with a hardened resin has first and second warp fabric sections, the second section comprising a plurality of pleats integrally joined to the first section by warp threads of the second section and interwoven with the weft threads of the first section. The fabric is of an industrial yarn such as aramide fiber, carbon fiber, ceramic fiber, glass fiber or a blend of such fibers.

Abstract: Undesirable attenuations are avoided in a light-conducting cable by providing a certain play between the coated light-conducting fiber and its outer protective casing which may include a reinforcing sheathing surrounding the coating and surrounded by an outer casing. Such play is achieved by temporarily providing a removable material radially inwardly, or in, or radially outwardly of the sheathing and then removing such temporary layer by chemically dissolving the layer, or melting, or evaporating the layer through the outer casing which is made permeable for this purpose.