Composite structure and method of making a composite structure

A composite structure comprising:

• a first fiber composite layer having a relative fiber direction of about 0°;
• and at least a second fiber composite layer having a relative fiber direction of between about 60° and 31 60°, inclusive, compared to the first composite layer, the layers being secured together and adjacent each other in an overlapping manner;
• and
• a plurality of inter-layer fibers knit into both the first and second composite layers.

A composite structure comprising:

• a first unit fiber composite layer;
• a second unit fiber composite layer;
• at least a third unit fiber composite layer;
• and
• resin secured to at least one of the composite unit layers, the unit layers being three-dimensionally woven together with fibers from the first unit composite layer being mechanically linked to fibers from the at least unit third or a deeper composite layer, and fibers from the first unit composite layer being mechanically linked to fibers from the unit second layer.

A composite structure comprising:

• a first tubular member;
• a second tubular member annularly disposed about the first tubular member;
• and
• a third tubular member having a smaller cross sectional size compared to the first tubular member;
• and
• a linking fiber phase disposed between the first, second and third tubular member, wherein each of the tubular members includes at least two composite sheets with offset angled fibers from one sheet relative to an adjacent sheet, the first, second and third tubular members having a fiber bundle woven between the first and second tubular members at an angle less than 10° relative to a tangent to the first tubular member.

A method of making a composite structure, the method comprising:

• (a) locating a first circular row of fibers oriented with a first fiber direction;
• (b) locating a second circular row of fibers interposed with the first circular row, oriented with a second fiber direction offset from the first fiber direction by about 60° −60°, inclusive;
• (c) locating a third circular row of fibers oriented with the first fiber direction;
• (d) knitting a plurality of fibers in both the first and third circular rows to form a 3A Q3D reinforcement phase;
• (e) impregnating the first, second, and third circular rows with uncured epoxy;
• (f) applying a vacuum to the sheets;
• (g) curving at least a portion of the sheets;
• and
• (h) curing resin in the sheets so that the sheets are bonded together, the curved portion remaining curved after the curing.