Composite tubular elements

A composite drive shaft for transmitting forces comprising:

• a cylindrical tubular metal core having a layer of structural metal adhesive from the circumference of the tubular metal core in an amount ranging from about 0.020 to about 0.040 lb/ft.sup.2 ;
• a plurality of layers of resin impregnated unidirectional continuous reinforcing fibers wrapped around said metal core, the fibers in said fiber reinforcing layers being selected from carbon and graphite fibers having a Youngs modulus of elasticity of about 30.times.10.sup.6 to about 50.times.10.sup.6 psi and a tensile strength of about 300,000 to about 400,000 psi, each layer of said resin impregnated fibers being generally quadrangular in shape, each layer of said resin impregnated fibers having a width of at least twice the circumference of the tubular core and only in full increments thereof, each layer of said resin impregnated fibers disposed in an opposite angled orientation with respect to the preceding layer of said resin impregnated fibers, said angle of orientation being between about 5.degree. and 12.degree. with respect to the longitudinal axis of the tubular metal core;
• and
• layers of woven fiberglass cloth interposed between alternating layers of said resin impregnated fibers, the fibers of the woven fiberglass cloth being oriented at 0.degree. and 90.degree. with respect to the longitudinal axis of the tubular metal core.

A composite drive shaft for a truck or car comprising:

• a tubular metal core formed from an alloy of aluminum having an inner diameter in the range of from about 21/4" to about 41/2" and having an outer diameter in the range of from about 21/2" to about 5", said metal core having a layer of structural metal adhesive on the periphery thereof in the range of about 0.020 to 0.040 lb/ft.sup.2 ;
• and,
• bonded to said core by said adhesive from about 2 to 10 plies of fiberglass scrim and an epoxy impregnated unidirectional continuous graphite fiber sheet material,
• each ply consisting of a layer of said scrim and a layer of the fiber sheet material, the orientation of the fibers of the fiberglass scrim being at 0.degree. and 90.degree. with respect to the longitudinal axis of the tubular core, and the orientation of the graphite fibers in said graphite fiber sheet material being at about 10.degree. with respect to the longitudinal axis of the metal core, each layer of graphite fiber sheet material having the same angle of orientation but of opposite direction from the next preceding layer.