초록

An impact resistant composite sandwich structure includes least one laminate face sheet joined to a stiffening element. The stiffening element includes a plurality of fibers and a resin for binding the fibers. The resin has a strain-to-failure greater than approximately 6%.

대표청구항 ▼

1. A composite sandwich structure, comprising: a stiffening element including a plurality of randomly oriented fibers;a resin for binding the fibers, the resin having a strain-to-failure greater than approximately 6%; andat least one laminate facesheet joined to the stiffening element. 2. The compos

1. A composite sandwich structure, comprising: a stiffening element including a plurality of randomly oriented fibers;a resin for binding the fibers, the resin having a strain-to-failure greater than approximately 6%; andat least one laminate facesheet joined to the stiffening element. 2. The composite sandwich structure of claim 1, wherein the fibers are carbon fibers arranged in, non-woven mat. 3. The composite sandwich structure of claim 1, wherein the fibers are glass fibers arranged in non-woven mat. 4. The composite sandwich structure of claim 1, wherein the laminate facesheet includes carbon fiber reinforced epoxy resin. 5. The composite sandwich structure of claim 1, wherein the stiffening element is a honeycomb core. 6. The composite sandwich structure of claim 1, wherein the resin includes benzoxazine. 7. The composite sandwich structure of claim 1, wherein the fibers constitute between approximately 20% and 65% by weight of the stiffening element. 8. A panel, comprising: a first facesheet;a second facesheet; anda core sandwiched between the first and second facesheets, the core including a plurality of randomly oriented non-woven fibers and a high strain resin binding the non-woven fibers together. 9. The panel of claim 8, wherein the fibers are carbon fibers. 10. The panel of claim 8, wherein the fibers are glass fibers. 11. The panel of claim 8, wherein: the core is a honeycomb core, andthe high strain resin has a strain-to-failure of greater than approximately 6%. 12. The panel of claim 8, wherein the panel further comprises: a plurality of fibrids binding the randomly oriented fibers together. 13. A method of making a core for aircraft structures, comprising: forming fiber sheets containing at least one of glass fibers and carbon fibers, wherein the fibers constitute between approximately 20 to 65% by weight of the sheet, including binding the fibers using a resin having a strength-to-failure greater than approximately 6%, and wherein the fibers are randomly oriented;bonding two or more of the fiber sheets using an adhesive;curing the adhesive;forming cells between the fiber sheets by expanding the fiber sheets;applying a high strain resin to the two or more expanded fiber sheets; andcuring the high strain resin. 14. The composite sandwich structure of claim 1 wherein the fibers comprise poly p-pheneylene-2,6-benzobisoxazole (PBO). 15. The composite sandwich structure of claim 14 wherein the PBO fibers are bound in a plurality of fibrids. 16. The panel of claim 8 wherein the resin comprises polybenzoxazine. 17. The panel of claim 8 wherein the fibers comprise poly p-pheneylene-2,6-benzobisoxazole (PBO). 18. The composite sandwich structure of claim 1, wherein the fibers are preimpregnated with the resin. 19. The composite sandwich structure of claim 1 further comprising a second facesheet. 20. A structure comprising: a stiffening element comprising a plurality of poly p-pheneylene-2,6-benzobisoxazole (PBO) fibers;a resin binding the PBO fibers, the resin comprising polybensoxazine; andat least one laminate facesheet joined to the stiffening element wherein the fibers are randomly oriented. 21. The structure of claim 20, wherein the resin and PBO fibers are bonded so as to comprise a strain-to-failure greater than approximately 6%. 22. The composite sandwich structure of claim 1 wherein the composite and face sheet comprise a panel. 23. The composite sandwich structure of claim 22 wherein the panel is disposed in an aircraft.