Hybrid three-dimensional woven/laminated struts for composite structural applications

Abstract

A woven preform used to reinforce a composite structure which includes a central portion having a plurality of inter-woven layers. The preform also includes first and second end portions having a plurality of independent woven layers that are integrally woven with the plurality of interwoven layers in the central portion and which extend along the entire length the preform. Interspersed between the plurality of independent woven layers in the first and second end portions are bias plies.

What is claimed is: 
     
       1. A woven preform used to reinforce a composite structure comprising:
 a central portion having a plurality of interwoven layers;   a first end portion having a plurality of independent woven layers;   a second end portion having said plurality of independent woven layers;   wherein plies of said plurality of independent woven layers extend through the entire length of said preform wherein said plies are integrally woven in said central portion to form a three dimensional fabric construction; and   wherein said plies are independently woven in said end portions to form a stack of woven fabric;   wherein bias plies are interspersed between said plurality of independent woven layers plies in said first and second end portions.   
     
     
       2. The woven preform as claimed in  claim 1 , wherein said central portion comprises a plurality of layers that extend long the entire length of said woven preform and a plurality of layers that partially extend along the length of said woven preform. 
     
     
       3. The woven preform as claimed in  claim 2 , wherein said partially extending layers are formed by warp fibers or yarns that weave out of said woven preform and provide a transition from said central portion to said first and second end portions. 
     
     
       4. The woven preform as claimed in  claim 2 , wherein gaps for said bias plies between said independent woven layers in said first and second end portions are a result of warp fibers or yarns that weave out of said woven preform. 
     
     
       5. The woven preform as claimed in  claim 1 , wherein said first end portion is a lug having a male or a female configuration. 
     
     
       6. The woven preform as claimed in  claim 1 , wherein said second end portion is a lug having a male or a female configuration. 
     
     
       7. The woven preform as claimed in  claim 1 , wherein said first end portion is collinear with or angled relative to said central portion. 
     
     
       8. The woven preform as claimed in  claim 1 , wherein said second end portion is collinear with or angled relative to said central portion. 
     
     
       9. The woven preform as claimed in  claim 3 , wherein said transition between said column portion and said first and second end portions is a smooth tapered transition or a staggered transition. 
     
     
       10. The woven preform as claimed in  claim 1 , wherein said central portion is bifurcated at an end of said central portion. 
     
     
       11. The woven preform as claimed in  claim 10 , wherein said bifurcated end forms two halves of a female lug or clevis. 
     
     
       12. The woven preform as claimed in  claim 1 , wherein said central portion is thicker than said first and second end portions. 
     
     
       13. The woven preform as claimed in  claim 1 , wherein said central portion is thinner than said first and second end portions. 
     
     
       14. The woven preform as claimed in  claim 1 , wherein said first end portion and said second end portion are woven with warp and weft fibers or yarns. 
     
     
       15. The woven preform as claimed in  claim 1 , wherein said layers in said central portion are woven layers woven with warp and weft fibers or yarns. 
     
     
       16. The woven preform as claimed in  claim 1 , wherein said central portion has a fiber architecture selected from the group consisting of ply-to-ply, through thickness, orthogonal, and angle interlock. 
     
     
       17. The woven preform as claimed in  claim 14  or  15 , wherein said warp and weft fibers or yarns are selected from the group of synthetic or natural materials consisting of carbon, nylon, rayon, polyester, fiberglass, cotton, glass, ceramic, aramid, and polyethylene. 
     
     
       18. The woven preform as claimed in  claim 1 , wherein said woven preform is overbraided with a ply of glass. 
     
     
       19. A method of manufacturing a woven preform used to reinforce a composite structure comprising the steps of:
 weaving a plurality of layers together to form a monolithic central portion;   weaving a plurality of independent layers to form a first end portion;   weaving said plurality of independent layers to form a second end portion, wherein plies of said plurality of independent woven layers extends through the entire length of said preform, wherein said plies are integrally woven in said central portion to form a three dimensional fabric construction, and wherein said plies are independently woven in said end portions to form a stack of woven fabric; and   interspersing bias plies between said plurality of independent woven plies in said first and said second end portions.   
     
     
       20. The method as claimed in  claim 19  further comprising the step of weaving warp fibers or yarns out of said woven preform in order to provide a transition from said central portion to said first and second end portions. 
     
     
       21. The method as claimed in  claim 19  further comprising the step of weaving warp fibers or yarns out of said woven preform to form independent woven layers in said first and second end portions thereby providing a gap between said independent woven layers for said bias plies. 
     
     
       22. The method as claimed in  claim 19 , wherein said first end portion is a lug having a male or a female configuration. 
     
     
       23. The method as claimed in  claim 19 , wherein said second end portion is a lug having a male or a female configuration. 
     
     
       24. The method as claimed in  claim 19 , wherein said first end portion is collinear with or angled relative to said central portion. 
     
     
       25. The method as claimed in  claim 19 , wherein said second end portion is collinear with or angled relative to said central portion. 
     
     
       26. The method as claimed in  claim 20 , wherein said transition between said column portion and said first and second end portions is a smooth tapered transition or a staggered transition. 
     
     
       27. The method as claimed in  claim 19 , wherein said central portion is woven to have bifurcation at an end of said central portion. 
     
     
       28. The method as claimed in  claim 27  wherein said bifurcated end forms two halves of a female lug or clevis. 
     
     
       29. The method as claimed in  claim 19 , wherein said central portion is thicker than said first and second end portions. 
     
     
       30. The method as claimed in  claim 19 , wherein said central portion is thinner than said first and second end portions. 
     
     
       31. The method as claimed in  claim 19 , wherein said central portion, said first end portion and said second end portion are woven with warp and weft fibers or yarns. 
     
     
       32. The method as claimed in  claim 19 , wherein said central portion is woven with a fiber architecture selected from the group consisting of ply-to-ply, through thickness, orthogonal, and angle interlock. 
     
     
       33. The method as claimed in  claim 19 , wherein said warp and weft fibers or yarns are selected from the group of synthetic or natural materials consisting of carbon, nylon, rayon, polyester, fiberglass, cotton, glass, ceramic, aramid, and polyethylene. 
     
     
       34. The method as claimed in  claim 19 , wherein said woven preform is overbraided with a ply of glass. 
     
     
       35. A three-dimensional composite structure reinforced with a woven preform comprising:
 a central portion having a plurality of interwoven layers;   a first end portion having a plurality of independent woven layers;   a second end portion having said plurality of independent woven layers;   wherein plies of said plurality of independent woven layers extend through the entire length of said preform wherein said plies are integrally woven in said central portion to form a three dimensional fabric construction; and   wherein said plies are independently woven in said end portions to form a stack of woven fabric;   wherein bias plies are interspersed between said plurality of independent woven layers plies in said first and second end portions; and   a matrix material.   
     
     
       36. The composite structure as claimed in  claim 35 , wherein said central portion comprises a plurality of layers that extend along the entire length of said woven preform and a plurality of layers that partially extend along the length of said woven preform. 
     
     
       37. The composite structure as claimed in  claim 36 , wherein said partially extending layers are formed by warp fibers or yarns that weave out of said woven preform and provide a transition from said central portion to said first and second end portions. 
     
     
       38. The composite structure as claimed in  claim 36 , wherein gaps for said bias plies between said independent woven layers in said first and second end portions are a result of warp fibers or yarns that weave out of said woven preform. 
     
     
       39. The composite structure as claimed in  claim 35 , wherein said first end portion is a lug having a male or a female configuration. 
     
     
       40. The composite structure as claimed in  claim 35 , wherein said second end portion is a lug having a male or a female configuration. 
     
     
       41. The composite structure as claimed in  claim 35 , wherein said first end portion is collinear with or angled relative to said central portion. 
     
     
       42. The composite structure as claimed in  claim 35 , wherein said second end portion is collinear with or angled relative to said central portion. 
     
     
       43. The composite structure as claimed in  claim 37 , wherein said transition between said column portion and said first and second end portions is a smooth tapered transition or a staggered transition. 
     
     
       44. The composite structure as claimed in  claim 35 , wherein said central portion is bifurcated at an end of said central portion. 
     
     
       45. The composite structure as claimed in  claim 44 , wherein said bifurcated end forms two halves of a female lug or clevis. 
     
     
       46. The composite structure as claimed in  claim 35 , wherein said central portion is thicker than said first and second end portions.  
     
     
       47. The composite structure as claimed in  claim 35 , wherein said central portion is thinner than said first and second end portions. 
     
     
       48. The composite structure as claimed in  claim 35 , wherein said first and said second end portions are quasi-isotropically or multi-directionally reinforced. 
     
     
       49. The composite structure as claimed in  claim 35 , wherein said first end portion and said second end portion are woven with warp and weft fibers or yarns. 
     
     
       50. The composite structure as claimed in  claim 35 , wherein said layers in said central portion are woven layers woven with warp and weft fibers or yarns. 
     
     
       51. The composite structure as claimed in  claim 35 , wherein said woven central portion has a fiber architecture selected from the group consisting of ply-to-ply, through thickness, orthogonal, and angle interlock. 
     
     
       52. The composite structure as claimed in  claim 49  or  50 , wherein said warp and weft fibers or yarns are selected from the group of synthetic or natural materials consisting of carbon, nylon, rayon, polyester, fiberglass, cotton, glass, ceramic, aramid, and polyethylene. 
     
     
       53. The composite structure as claimed in  claim 36 , wherein said composite structure is formed from a process selected from the group consisting of resin transfer molding and chemical vapor filtration. 
     
     
       54. The composite structure as claimed in  claim 53 , wherein said matrix material is selected from the group consisting of epoxy, polyester, vinyl-ester, ceramic, and carbon. 
     
     
       55. A woven preform used to reinforce a composite structure comprising:
 a column portion having a plurality of interwoven layers; and   a lug end portion having a plurality of independent woven layers, wherein plies of said plurality of independent woven layers extend through the entire length of said preform wherein said plies are integrally woven in said column portion to form a three dimensional fabric construction; and   wherein said plies are independently woven in said end portion to form a stack of woven fabric;   wherein bias plies are interspersed between said plurality of independent woven layers plies in said lug end portion.   
     
     
       56. The woven preform as claimed in  claim 55 , wherein said lug end portion has a male or female configuration. 
     
     
       57. The woven preform as claimed in  claim 55 , wherein said lug end portion is collinear with or angled relative to said column portion. 
     
     
       58. The woven preform as claimed in  claim 55 , wherein said column portion is thicker than said lug end portion. 
     
     
       59. The woven preform as claimed in  claim 55 , wherein said column portion is thinner than said lug end portion. 
     
     
       60. The woven preform as claimed in  claim 55 , further comprising a matrix material. 
     
     
       61. A woven preform for use as reinforcement in a composite structure comprising:
 a three-dimensional central portion having a plurality of warp fibers interwoven with a plurality of weft fibers in three dimensions (X, Y, and Z);   a first end portion; and   a second end portion;   wherein said woven preform comprises one or more warp fibers on an outer surface of said preform that extend continuously on the outer surface along the entire length of said woven preform; and   wherein said woven preform comprises one or more warp fibers that extend along the entire length of said woven preform and a plurality of warp fibers that weave out of said woven preform and provide a transition from said central portion to at least one of said first and second end portions.   
     
     
       62. A method of manufacturing a woven preform for use as reinforcement in a composite structure comprising the steps of:
 weaving a plurality of warp fibers with a plurality of weft fibers in three dimensions (X, Y, and Z) to form a three-dimensional central portion;   weaving a plurality of the warp fibers with a plurality of weft fibers in three dimensions (X, Y, and Z) to form a three-dimensional first end portion;   weaving a plurality of the warp fibers with a plurality of weft fibers in three dimensions (X, Y, and Z) to form a three-dimensional second end portion;   wherein the woven preform comprises one or more warp fibers on an outer surface of said woven preform are woven to extend along the entire length of said woven preform; and   wherein said woven preform comprises one or more warp fibers that extend continuously on outer surface along the entire length of said woven preform and a plurality of warp fibers that weave out of said woven preform and provide a transition from said central portion to at least one of said first and second end portions.   
     
     
       63. A woven preform for use as reinforcement in a composite structure comprising:
 a three-dimensional central portion having a plurality of warp fibers interwoven with a plurality of weft fibers in three dimensions (X, Y, and Z); and   wherein said woven preform comprises one or more warp fibers on an outer surface of said woven preform that extend continuously on the outer surface along the entire length of said woven preform; and   wherein two or more warp fibers in adjacent layers exchange position through a thickness of the central portion at a bifurcation at an end of said central portion.   
     
     
       64. A method of manufacturing a woven preform for use as reinforcement in a composite structure comprising the step of:
 weaving a plurality of warp fibers with a plurality of weft fibers in three dimensions (X, Y, and Z) to form a three-dimensional central portion of the woven preform such that one or more warp fibers extend continuously on an outer surface of the three-dimensional central portion of the preform and extend along the entire length of said woven preform;   wherein two or more warp fibers in adjacent layers of the central portion are woven to exchange position through a thickness of the central portion at a bifurcation at an end of said central portion.   
     
     
       65. A woven preform for use as reinforcement in a composite structure comprising:
 at least one end portion; and   a three-dimensionally woven central portion comprising a plurality of warp fibers interwoven with a plurality of weft fibers in three dimensions (X, Y, and Z) comprising:
 the plurality of weft fibers comprising first yarns extending in a weft direction; 
 the plurality of warp fibers comprising second yarns extending in a warp direction, wherein the first and second yarns form interwoven layers in the central portion; 
 wherein there is a greater number of second yarns in a first region of the woven central portion than in a second region of the woven central portion. 
   
     
     
       66. A method of forming a woven preform comprising a three-dimensionally woven central portion and at least one end portion for use as reinforcement in a composite structure comprising the steps of:
 weaving first yarns extending in a weft direction and second yarns extending in a warp direction to form the three-dimensionally woven central portion at a first region of the preform;   weaving out select second yarns in three dimensions (X, Y, and Z) in a second region of the preform to reduce a thickness of the three-dimensionally woven central portion in the second region.   
     
     
       67. A woven preform for use as reinforcement in a composite structure comprising:
 at least one end portion; and   a three-dimensionally woven central portion comprising a plurality of warp yarns interwoven with a plurality of weft yarns in three dimensions (X, Y, and Z),   wherein one or more warp yarns extend along the entire length of said preform, and one or more warp yarns extend less than the entire length of said preform.