Preform and method for reinforcing woven fiber nodes
Preforms including fiber reinforced nodes for use in fiber reinforced composite structures and methods for making fiber reinforced composite structures. Preforms with woven fabric elements extending radially from a common node include at least one reinforcing fiber interwoven between at least two elements and passing through the node. A method of assembling preform structures using the preforms to provide a structure with reinforced nodes.
1. A reinforced preform comprising:
a plurality of commonly woven fabric elements edgewise joined and radially extending from a common node,
wherein at least one reinforcing fiber from each of the plurality of elements is woven through the node and into at least one other of the plurality of elements;
wherein the elements further comprise major surfaces; and wherein at least some of the plurality of elements are arranged in pairs of adjacent elements such that opposite facing adjacent major surfaces are spaced apart a distance and form a void therebetween, and
wherein the plurality of elements comprise at least two sets of the elements arranged in pairs, and at least two singular elements.
2. The preform of claim 1 wherein all of the plurality of elements are arranged in pairs.
3. The preform of claim 1 , wherein the plurality of elements comprises
two sets of the elements arranged in pairs, and two singular elements.
4. A composite structure comprising:
a plurality of preforms, each comprising a plurality of commonly woven fabric elements edgewise joined and radially extending from a common node, the fabric elements comprising major surfaces and having at least one reinforcing fiber from each of the plurality of elements woven through the node and into at least one other of the plurality of fabric elements;
wherein a first of the plurality of preforms comprises adjacent woven fabric elements arranged in pairs such that opposite facing adjacent major surfaces are spaced apart a distance and form a first void therebetween; and
the structure further comprising a secondary element, a first end of which is at least partially received within the first void.
5. The composite structure of claim 4 further comprising:
a second preform of the plurality of preforms comprising adjacent elements arranged in pairs such that opposite facing adjacent major surfaces are spaced apart a distance and form a void therebetween; and
a second end of the secondary element is at least partially received within the second void formed in the second preform, at least partially overlapping and abutting at least one of the opposite facing adjacent major surfaces thereof.
6. The composite structure of claim 5 wherein the secondary element comprises a woven fabric.
7. The composite structure of claim 4 comprising at least one preform wherein all of the plurality of elements are arranged in pairs.
8. The composite of claim 4 , comprising at least one preform wherein the plurality of elements comprises:
at least one set of the elements is arranged in pairs, and at least one singular element.
9. The composite structure of claim 8 wherein each preform comprises
two sets of the elements arranged in pairs, and two singular elements, and
the composite structure is assembled such that each single element is accepted within the void formed between the pairs of elements.
10. A method of forming a reinforced composite structure comprising the following steps
fabricating a first reinforced preform comprising a plurality of commonly woven fabric elements edgewise joined and radially extending from a common node wherein at least one reinforcing fiber from each of the plurality of elements is woven through the node and into at least one other of the plurality of elements, wherein the fabric elements of the first reinforced preform comprise major surfaces;
fabricating a second preform comprising at least one secondary element the second preform further comprising a plurality of secondary elements, the secondary elements comprising major surfaces; and
the first reinforced preform and the second preform each having longitudinal axes;
arranging the first reinforced preform and the second preform with their longitudinal axes generally parallel; and
positioning the first reinforced preform and the second preform such that a portion of at least one of the major surfaces of the first reinforced preform at least partially overlaps and abuts a portion of at least one of the major surfaces of a secondary element of the second preform;
arranging at least some of the fabric elements of the first reinforced preform in pairs of adjacent elements such that opposite facing adjacent major surfaces are spaced apart a distance and form a void therebetween; and
positioning at least a portion of a first end of one of the plurality of secondary elements within one of the voids formed in the first reinforced preform, overlapping and abutting at least a portion of one of the opposite facing adjacent major surfaces thereof; and
processing the preform assembly to form a composite structure.
11. The method of claim 10 , further comprising;
fabricating the second reinforced preform comprising a plurality of commonly woven fabric elements edgewise joined and radially extending from a common node, the fabric elements comprising major surfaces and having at least one reinforcing fiber from each of the plurality of elements woven through the node and into at least one other of the plurality of elements;
arranging at least some of the fabric elements of the second reinforced preform in pairs of adjacent elements such that opposite facing adjacent major surfaces are spaced apart a distance and form a void therebetween; and
positioning a second end of the secondary element such that it is at least partially received in one of the voids formed in the second reinforced preform, overlapping and abutting at least a portion of one of the opposite facing adjacent major surfaces thereof.