What is claimed is:
1. A method for forming panel stiffeners, comprising:
inserting one or more flexible mandrels into each of one or more channels of a tool having a three-dimensional contour, the one or more flexible mandrels being composed of silicone rubber;
hardening the flexible mandrels while inserted in the one or more channels of the tool; and
forming stiffeners using the hardened one or more mandrels.
2. The method of claim 1 , wherein hardening the flexible mandrels while inserted in the one or more channels comprises inserting a hardening substance into the flexible mandrels.
3. The method of claim 2 , wherein inserting a hardening substance into the flexible mandrels comprises applying vacuum pressure at one end of the flexible mandrels to draw the hardening substance into the mandrel.
4. A method for forming panel stiffeners, comprising:
inserting one or more flexible mandrels into each of one or more channels of a tool having a three-dimensional contour, wherein the tool is composed of foam;
hardening the flexible mandrels while inserted in the one or more channels of the tool; and
forming stiffeners using the hardened one or more mandrels.
5. The method of claim 1 , wherein forming stiffeners using the hardened one or more mandrels comprises:
wrapping the mandrels with a stiffener material; and
forming the stiffener material into a stiffener shape.
6. The method of claim 5 , wherein the stiffener shape is selected from the group consisting of an I-stiffener, a J-stiffener, and a blade stiffener.
7. The method of claim 1 , further comprising:
placing a vacuum bag over the flexible mandrels and the tool, wherein the mandrels are disposed between the vacuum bag and the tool; and
applying vacuum pressure between the vacuum bag and the tool.
8. The method of claim 7 , further comprising placing a breathable material over the flexible mandrels, wherein the breathable material is disposed between the flexible mandrels and the vacuum bag.
9. The method of claim 1 , wherein the tool is formed using a panel having a three-dimensional contour, and the method further comprises coupling the stiffeners to the panel.
10. The method of claim 4 , wherein hardening the flexible mandrels while inserted in the one or more channels comprises inserting a hardening substance into the flexible mandrels.
11. The method of claim 10 , wherein inserting a hardening substance into the flexible mandrels comprises applying vacuum pressure at one end of the flexible mandrels to draw the hardening substance into the mandrel.
12. The method of claim 4 , wherein forming stiffeners using the hardened one or more mandrels comprises:
wrapping the mandrels with a stiffener material; and
forming the stiffener material into a stiffener shape.
13. The method of claim 12 , wherein the stiffener shape is selected from the group consisting of an I-stiffener, a J-stiffener, and a blade stiffener.
14. The method of claim 4 , further comprising:
placing a vacuum bag over the flexible mandrels and the tool, wherein the mandrels are disposed between the vacuum bag and the tool; and
applying vacuum pressure between the vacuum bag and the tool.
15. The method of claim 14 , further comprising placing a breathable material over the flexible mandrels, wherein the breathable material is disposed between the flexible mandrels and the vacuum bag.
16. The method of claim 4 , wherein the tool is formed using a panel having a three-dimensional contour, and the method further comprises coupling the stiffeners to the panel.