Forming systems and methods for forming an elongate charge of composite material
Forming systems and methods for forming an elongate charge of composite material are disclosed herein. The forming systems include an elongate forming tool having an elongate forming surface with a forming surface shape. The forming systems also include an elongate end effector, which is configured to tension the elongate charge of composite material across the elongate forming surface. The elongate end effector includes an elongate vacuum distribution manifold, a porous elongate vacuum region that is defined by a strip of porous material, and an elongate friction surface that is defined by a strip of friction material. The strip of friction material is proximate a trailing edge of the elongate end effector relative to the strip of porous material. The methods include tensioning an elongate charge of composite material across an elongate forming surface of an elongate forming tool utilizing an elongate end effector.
1 . A forming system configured to form an elongate charge of composite material to a predefined material shape, the forming system comprising:
an elongate forming tool having an elongate forming surface with a forming surface shape that corresponds to the predefined material shape; and
an elongate end effector, wherein the elongate end effector is configured to tension the elongate charge of composite material across the elongate forming surface, and further wherein the elongate end effector includes:
(i) an elongate vacuum distribution manifold including a vacuum inlet, which is configured to receive an applied vacuum, and a vacuum outlet;
(ii) a porous elongate vacuum region, which is defined by a strip of porous material and is configured to receive the applied vacuum from the vacuum outlet to generate a pressure differential that is configured to retain the elongate charge of composite material in contact with the porous elongate vacuum region; and
(iii) an elongate friction surface, which is defined by a strip of friction material and extends along a length of the strip of porous material, wherein the elongate friction surface is configured to generate a frictional force that resists a sliding motion between the elongate end effector and the elongate charge of composite material, and wherein the strip of friction material is proximate a trailing edge of the elongate end effector relative to the strip of porous material;
wherein at least one of:
(i) a coefficient of static friction between the elongate charge of composite material and the elongate friction surface is greater than a coefficient of static friction between the elongate charge of composite material and the porous elongate vacuum region; and
(ii) a coefficient of kinetic friction between the elongate charge of composite material and the elongate friction surface is greater than a coefficient of kinetic friction between the elongate charge of composite material and the porous elongate vacuum region.
2 . The forming system of claim 1 , wherein the strip of friction material extends adjacent the strip of porous material along the length of the elongate end effector.
3 . The forming system of claim 1 , wherein the strip of friction material is within 5 millimeters (mm) of the trailing edge of the elongate end effector.
4 . The forming system of claim 1 , wherein the elongate friction surface has a friction surface width of at least 2 mm and at most 8 mm.
5 . The forming system of claim 1 , wherein the porous elongate vacuum region has a vacuum region width of at least 2 mm and at most 8 mm.
6 . The forming system of claim 1 , wherein the elongate friction surface has a friction surface aspect ratio of at least 100.
7 . The forming system of claim 1 , wherein the elongate friction surface has a friction surface area, wherein the porous elongate vacuum region has a vacuum surface area, and further wherein the friction surface area has at least 0.1 times and at most 2 times the vacuum surface area.
8 . The forming system of claim 1 , wherein the strip of porous material projects from an external body surface of a manifold body that defines the elongate vacuum distribution manifold by a body projection distance of at least 0.1 mm and at most 1 mm.
9 . The forming system of claim 1 , wherein the strip of friction material projects from an external body surface of a manifold body that defines the elongate vacuum distribution manifold by a body projection distance of at least 0.1 mm and at most 1 mm.
10 . The forming system of claim 1 , wherein the forming system further includes an end effector positioning structure configured to operatively translate the elongate end effector relative to the elongate forming surface to tension the elongate charge of composite material across the elongate forming surface.
11 . The forming system of claim 1 , wherein the forming system further includes a compaction structure configured to compact the elongate charge of composite material against the elongate forming surface.
12 . The forming system of claim 11 , wherein the compaction structure is configured to compact the elongate charge of composite material while the elongate end effector maintains tension within the elongate charge of composite material.
13 . The forming system of claim 11 , wherein the compaction structure is configured to urge the elongate end effector out of contact with the elongate charge of composite material during compaction of the elongate charge of composite material.
14 . The forming system of claim 11 , wherein the forming system is configured to coordinate motion of the elongate end effector and the compaction structure to simultaneously tension and compact the elongate charge of composite material.
15 . The forming system of claim 1 , wherein the forming system further includes a vacuum source configured to generate the applied vacuum and to provide the applied vacuum to the vacuum inlet of the elongate end effector.
16 . The forming system of claim 1 , wherein the strip of porous material includes at least one of:
i) a strip of open cell foam;
(ii) a strip of open cell polyethylene foam;
(iii) a strip of sintered material; and
(iv) a strip of perforated material.
17 . A method of operating the forming system of claim 1 , the method comprising:
positioning the elongate charge of composite material on the elongate forming surface;
attaching an attached region of the elongate charge of composite material to the elongate forming surface;
applying the applied vacuum to generate the pressure differential across the porous elongate vacuum region of the elongate end effector;
retaining a retained region of the elongate charge of composite material on the porous elongate vacuum region via the pressure differential;
during the retaining, moving the elongate end effector away from the attached region of the elongate charge of composite material to tension the elongate charge of composite material across the elongate forming surface; and
during the moving and with the elongate end effector, resisting the sliding motion between the elongate charge of composite material and the elongate end effector when a shear force between the elongate charge of composite material and the elongate end effector is less than a threshold shear force magnitude and permitting the sliding motion between the elongate charge of composite material and the elongate end effector when the shear force is greater than the threshold shear force magnitude;
wherein the elongate end effector further includes the elongate friction surface that extends adjacent to the porous elongate vacuum region; and
wherein the moving includes moving such that the elongate friction surface is proximate the trailing edge of the elongate end effector relative to the porous elongate vacuum region.
18 . The method of claim 17 , wherein the method further includes releasing the elongate charge of composite material from the porous elongate vacuum region prior to releasing the elongate charge of composite material from the elongate friction surface.
19 . The method of claim 17 , wherein the moving includes sliding an edge of the elongate charge of composite material across the porous elongate vacuum region prior to sliding the edge across the elongate friction surface.
20 . The method of claim 17 , wherein during the moving, the elongate friction surface is within 5 millimeters (mm) of the trailing edge of the elongate end effector.