초록 ▼

A method for forming complexly shaped composite laminate assemblies. A pair of dry fiber preforms are placed on a tool with a thin film adhesive layer therebetween. A vacuum bag encloses the preforms and the adhesive layer. The preforms are heated to a temperature sufficient to cause the adhesive to

A method for forming complexly shaped composite laminate assemblies. A pair of dry fiber preforms are placed on a tool with a thin film adhesive layer therebetween. A vacuum bag encloses the preforms and the adhesive layer. The preforms are heated to a temperature sufficient to cause the adhesive to become viscous and to wet several plys of each of the preforms. The preforms are then allowed to cool slightly before resin is infused via a vacuum source through each of the preforms to thoroughly wet each of the preforms. The resulting joint formed at the bond line of the two preforms is stronger than what would be formed simply by adhering two otherwise completely formed preforms together because the dry fiber preforms, in connection with the heating of the preforms, allow wetting of several plys of each of the preforms at the joint area, rather than just the surface ply of each preform.

대표청구항 ▼

What is claimed is: 1. A method for forming a composite skin panel from first and second independent dry fiber preforms, each said independent dry fiber preform including a plurality of layers of fiber material without any adhesive between adjacent layers within each respective dry fiber preform, t

What is claimed is: 1. A method for forming a composite skin panel from first and second independent dry fiber preforms, each said independent dry fiber preform including a plurality of layers of fiber material without any adhesive between adjacent layers within each respective dry fiber preform, the method comprising: disposing an adhesive only at one or more interfaces of the dry fiber preforms before the dry fiber preforms are infused with resin; placing the dry fiber preforms with the adhesive therebetween within an airtight enclosure; heating the adhesive to a temperature sufficient to cause the adhesive to become viscous; applying a vacuum to the airtight enclosure to cause the viscous adhesive to flow into and at least substantially saturate a subplurality of layers of each said dry fiber preform; after the subplurality of layers are substantially saturated with the viscous adhesive, then infusing a resin into the dry fiber preforms and using the vacuum to draw the resin through the dry fiber preforms to substantially saturate the preforms with resin; and curing the adhesive and the resin within the preforms to form a composite skin panel in which one of said preforms comprises a skin and the other of said preforms comprises a stiffener bonded to the skin. 2. The method of claim 1, wherein the adhesive at least partially bonds the preforms to one another before the preforms are infused with resin. 3. The method of claim 1, wherein the method includes assembling the dry fiber preforms with adhesive therebetween on a tool of a vacuum assisted resin transfer molding apparatus. 4. The method of claim 3, wherein the placing, heating, applying, infusing, and curing are each performed while the preforms are on the tool. 5. The method of claim 3, wherein the assembling, placing, heating, applying, infusing, and curing are all performed in a single manufacturing operation. 6. The method of claim 1, wherein the method includes enhancing bonding of the preforms to one another by causing increased migration of viscous adhesive into the subplurality of layers of the dry fiber preforms. 7. The method of claim 6, wherein the method includes further enhancing bonding of the preforms to one another by causing the resin to substantially backfill interstices and voids in areas of the subplurality of layers where the adhesive has not saturated. 8. The method of claim 1, wherein the adhesive disposed only at the one or more interfaces is a self-supporting film of adhesive. 9. A method for forming first and second dry fiber preforms into a composite laminate structure, each said dry fiber preform including a plurality of layers of fiber material, the method comprising: placing an adhesive against only a surface of the first dry fiber preform which is to be bonded to a surface of the second dry fiber preform; placing the second dry fiber preform against the adhesive such that the adhesive is only between the surfaces of the dry fiber preforms to be bonded to one another; placing the first and second dry fiber preforms with the adhesive therebetween within an airtight enclosure; heating the adhesive to a temperature sufficient to cause the adhesive to become viscous; causing the viscous adhesive to flow into and at least substantially saturate a subplurality of layers of each said dry fiber preform; and after the subplurality of layers of the dry fiber preforms are substantially saturated with the viscous adhesive, then infusing a resin into the dry fiber preforms to thoroughly wet the dry fiber preforms. 10. The method of claim 9, further comprising curing the adhesive and the resin in the preforms whereupon curing the preforms are bonded to one another to form the composite laminate structure. 11. The method of claim 10, wherein the curing comprises heating the preforms to a temperature between about 200 degrees Fahrenheit and 400 degrees Fahrenheit for a predetermined period of time. 12. The method of claim 9, wherein: the airtight enclosure comprises a vacuum bag; and the causing includes applying a vacuum to the vacuum bag to cause the viscous adhesive to flow into the subplurality of layers of each said dry fiber preform. 13. The method of claim 9, wherein the heating includes heating the dry fiber preforms to a temperature of between about 150 degrees Fahrenheit and 300 degrees Fahrenheit. 14. The method of claim 13, wherein the method includes, after the subplurality of layers of the dry fiber preforms are substantially saturated with the viscous adhesive, allowing the dry fiber preforms to cool to a temperature of between about 70 degrees Fahrenheit and 200 degrees Fahrenheit before beginning to infuse the resin into the dry fiber preforms. 15. The method of claim 9, wherein the adhesive at least partially bonds the first dry fiber preform to the second dry fiber preform before beginning to infuse the resin into the dry fiber preforms. 16. The method of claim 9, wherein the heating, causing, and infusing are all performed while the preforms are on a tool of a vacuum assisted resin transfer molding apparatus. 17. The method of claim 9, wherein the adhesive placed against the surface of the first dry fiber preform is a self-supporting film of adhesive. 18. The method of claim 9, wherein the method includes enhancing bonding of the preforms to one another by causing increased migration of viscous adhesive into the subplurality of layers of the dry fiber preforms. 19. The method of claim 18, wherein the method includes enhancing bonding of the preforms to one another by causing the resin to substantially backfill interstices and voids in areas of the subplurality of layers where the adhesive has not saturated. 20. A method for forming a composite laminate structure from first and second dry fiber preforms, each said dry fiber preform including a plurality of layers of fiber material, the method comprising: placing a layer of thin film adhesive against only a surface of the first dry fiber preform which is to be bonded to a surface of the second dry fiber preform; placing a second dry fiber preform against the layer of thin film adhesive such that the layer of thin film adhesive is only between the surfaces of the dry fiber preforms to be bonded to one another, thereby forming a composite laminate assembly without any adhesive between adjacent layers within each respective dry fiber preform; placing the composite laminate assembly within a vacuum bag; heating the composite laminate assembly to a predetermined temperature sufficient to cause the layer of thin film adhesive to become viscous causing the adhesive to flow into a subplurality of layers of each said dry fiber preform, to thereby at least substantially saturate the subplurality of layers; after the subplurality of layers are substantially saturated with the viscous adhesive, then infusing a resin into the dry fiber preforms and applying a vacuum to the vacuum bag to draw the resin through the dry fiber preforms to thoroughly wet the dry fiber preforms; and curing the composite laminate assembly to form the composite laminate structure. 21. The method of claim 20, wherein the composite laminate assembly is heated to a temperature between about 150 degrees Fahrenheit and 300 degrees Fahrenheit to cause the layer of thin film adhesive to become viscous. 22. The method of claim 20, wherein the composite laminate assembly is heated to a temperature of approximately 250 degrees Fahrenheit to cause the layer of thin film adhesive to become viscous. 23. The method of claim 20, wherein the composite laminate assembly is allowed to cool to a temperature below the predetermined temperature that caused the layer of thin film adhesive to become viscous after the viscous adhesive has at least substantially saturated the subplurality of layers of the dry fiber preforms and before infusing the resin into the dry fiber preforms. 24. The method of claim 20, wherein: the composite laminate assembly is heated to a temperature of between about 150 degrees Fahrenheit and 300 degrees Fahrenheit to cause the layer of thin film adhesive to become viscous; and the dry fiber preforms are allowed to cool to a temperature of between about 70 degrees Fahrenheit and 200 degrees Fahrenheit after the viscous adhesive has at least partially saturated the subplurality of layers of the dry fiber preforms and before infusing the resin into the dry fiber preforms. 25. The method of claim 20, wherein the curing is accomplished by heating the composite laminate assembly to a temperature of between about 200 degrees Fahrenheit and 400 degrees Fahrenheit. 26. The method of claim 20, wherein the curing is accomplished by heating the composite laminate assembly to a temperature of approximately 350 degrees Fahrenheit for a predetermined length of time. 27. The method of claim 26, wherein the predetermined length of time comprises a duration of between about fours hours and eight hours. 28. A method for forming at least a pair of independent dry fiber preforms into a composite laminate structure, each said dry fiber preform including a plurality of layers of fiber material, the method comprising: disposing a thin film adhesive layer only between surfaces of the dry fiber preforms which are to be bonded to one another, thereby forming a composite laminate assembly without any adhesive between adjacent layers within each respective dry fiber preform; placing the composite laminate assembly within a vacuum enclosure; heating the composite laminate assembly sufficient to cause the thin film adhesive layer to become viscous; applying a vacuum to the vacuum enclosure to cause the viscous adhesive to flow into a subplurality of the plurality of layers of each said dry fiber preform to substantially saturate the subplurality of layers; waiting a period of time for the dry fiber preforms to cool down to a second temperature; once the dry fiber preforms reach the second temperature, using the vacuum to draw resin from a resin reservoir in communication with the vacuum enclosure through the dry fiber preforms to thoroughly wet the dry fiber preforms; and after the preforms have been thoroughly wetted by the resin, further heating the composite laminate assembly to a third temperature greater than the first temperature to cure the adhesive and the resin in the preforms, whereupon curing the preforms are bonded to one another to form the composite laminate structure. 29. The method of claim 28, wherein the first temperature comprises a temperature within the range of about 150 degrees Fahrenheit to 300 degrees Fahrenheit. 30. The method of claim 28, wherein the second temperature comprises a temperature within the range of about 70 degrees Fahrenheit to 200 degrees Fahrenheit. 31. The method of claim 28, wherein the third temperature comprises a temperature within the range of about 200 degrees Fahrenheit to 400 degrees Fahrenheit. 32. The method of claim 28, wherein the method includes allowing the adhesive to at least partially cure before heating the composite laminate assembly to the third temperature. 33. The method of claim 28, wherein heating the composite laminate assembly to the third temperature fully cures the adhesive and the resin.