Apparatus and method to enable in-plane bending of high contour composite structures in post-forming operations

Patent metadata

Field	Value
Publication number	US-11766840-B2
Application number	US-202117461606-A
Country	US
Kind code	B2
Filing date	Aug 30, 2021
Priority date	Aug 30, 2021
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

There is provided a forming apparatus for forming a high contour composite structure. The forming apparatus includes an upper die and a lower die between which a composite charge is formed. The forming apparatus further includes a plurality of load cells, a control system, and an overlay tool assembly coupled to the upper die. The overlay tool assembly has scalloped sections positioned between pairs of the plurality of load cells, and positioned against portion(s) of the composite charge. The composite charge has ply discontinuity features through the one or more portions. The overlay tool assembly denies pressure and a through thickness compaction to the one or more portions of the composite charge during a forming process, to allow one or more plies in the one or more portions to move after the forming process, and to enable in-plane bending of the high contour composite structure in post-forming operations.

First claim

What is claimed is:

1. A forming apparatus for forming a high contour composite structure, the forming apparatus comprising:
an upper die and a lower die between which a composite charge is formed, the upper die having upper die portions that are slidably displaceable, via first actuators, and the lower die having pairs of die blocks spaced apart to define a die cavity, and slidably displaceable, via second actuators;
a plurality of load cells coupled to the first actuators, to monitor pressure applied to the composite charge by the first actuators and the second actuators;
a control system having a controller to operably control the first actuators and the second actuators; and
an overlay tool assembly coupled to the upper die, the overlay tool assembly having scalloped sections positioned between pairs of the plurality of load cells along a length of the upper die, and positioned against one or more portions of the composite charge during a forming process, the composite charge having ply discontinuity features formed through the one or more portions and aligned with the scalloped sections,
wherein the overlay tool assembly denies pressure and a through thickness compaction to the one or more portions of the composite charge during the forming process, to allow one or more plies in the one or more portions to move after the forming process, and to enable in-plane bending of the high contour composite structure, formed by the composite charge, in one or more post-forming operations.

2. The forming apparatus of claim 1 , wherein the upper die further comprises a punch designed for at least partial insertion into the die cavity, and the scalloped sections of the overlay tool assembly are attached along sides of the punch.

3. The forming apparatus of claim 2 , wherein the overlay tool assembly further comprises a shape conversion element for coupling over the punch, the shape conversion element having a shape conversion element shape that is different than a punch shape of the punch.

4. The forming apparatus of claim 1 , wherein the overlay tool assembly further comprises a punch element designed for at least partial insertion into the die cavity.

5. The forming apparatus of claim 1 , wherein the ply discontinuity features comprise splices formed through a thickness of the one or more portions of the composite charge, the splices comprising one of a partial splice, and a full zig-zag splice.

6. The forming apparatus of claim 1 , wherein the ply discontinuity features comprise relief cuts formed in the one or more plies through a thickness of the one or more portions of the composite charge, the relief cuts comprising one or more of dart-shaped relief cuts, and diamond-shaped relief cuts.

7. The forming apparatus of claim 1 , wherein the scalloped sections of the overlay tool assembly are positioned against flange areas of the composite charge, and the composite charge is formed into a hat-shaped stringer having flanges, webs, and a cap.

8. The forming apparatus of claim 7 , wherein the ply discontinuity features are formed in the flange areas prior to the forming process.

9. The forming apparatus of claim 1 , wherein the high contour composite structure comprises one of a stringer, an aircraft stringer, a hat-shaped stringer, a C-shaped stringer, an L-shaped stringer, a T-shaped stringer, a stiffener member, a spar, and a beam.

10. A forming apparatus for forming a high contour composite structure, the forming apparatus comprising:
an upper die assembly comprising a plurality of compressor module assemblies comprising compressor modules movably coupled to upper actuator assemblies, and coupled to a pair of lateral pressure plates, with a punch disposed between the pair of lateral pressure plates;
a lower die assembly comprising a lower pallet coupled to lower actuator assemblies, and having a presser apparatus disposed between pairs of die portions spaced apart to define a lower die cavity, the die portions being slidably displaceable with respect to each other, and the lower die assembly being separate from the upper die assembly, between which a composite charge having ply discontinuity features formed through one or more portions is formed;
a plurality of load cells coupled to, and aligned between, the upper actuator assemblies and the compressor modules of the upper die assembly, to monitor pressure applied to the composite charge by the upper actuator assemblies; and
a control system having a controller to operably control the upper actuator assemblies and the lower actuator assemblies,
wherein the upper die assembly, the lower die assembly, or a combination of the upper die assembly and the lower die assembly, is segmented into separate and independently movable segments having gaps formed between the separate and independently movable segments, and the separate and independently movable segments are controlled, with the controller, to vary pressure and a through thickness compaction to the one or more portions of the composite charge, along a length of the composite charge, during a forming process, to allow one or more plies in the one or more portions to move after the forming process, and to enable in-plane bending of the high contour composite structure, formed by the composite charge, in one or more post-forming operations.

11. The forming apparatus of claim 10 , wherein the upper die assembly is segmented and comprises a segmented upper die assembly, and the separate and independently movable segments comprise segmented upper die assembly segments, wherein during the forming process, one or more of the segmented upper die assembly segments are deactivated by the controller, and one or more of the segmented upper die assembly segments are activated by the controller.

12. The forming apparatus of claim 10 , wherein the compressor modules comprise electrically controlled compressor modules, or pneumatically controlled compressor modules.

13. The forming apparatus of claim 10 , wherein the lower die assembly is segmented and comprises a segmented lower die assembly, and the separate and independently movable segments comprise segmented lower die assembly segments.

14. The forming apparatus of claim 10 , wherein the combination of the upper die assembly and the lower die assembly is segmented, and the upper die assembly comprises a segmented upper die assembly, and the separate and independently movable segments comprise segmented upper die assembly segments, and the lower die assembly comprises a segmented lower die assembly, and the separate and independently movable segments comprise segmented lower die assembly segments, and further wherein each of the segmented upper die assembly segments is aligned with each of the segmented lower die assembly segments.

15. A method to enable in-plane bending of a high contour composite structure in one or more post-forming operations, the method comprising the steps of:
providing a forming apparatus comprising:
an upper die and a lower die between which a composite charge is formed, the upper die having upper die portions that are slidably displaceable, via first actuators, and the lower die having pairs of die blocks spaced apart to define a die cavity, and slidably displaceable, via second actuators;
a plurality of load cells coupled to the first actuators, to monitor pressure applied to the composite charge by the first actuators and the second actuators;
a control system having a controller to operably control the first actuators and the second actuators; and
an overlay tool assembly coupled to the upper die, the overlay tool assembly having scalloped sections position

Assignees

• Boeing Co

Inventors

• Kendall James R
• Suriyaarachchi Raviendra S
• Modin Andrew E

Classifications

• B29C70/345 Primary

  using matched moulds · CPC title

• B29C70/54

  Component parts, details or accessories; Auxiliary operations {, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing} · CPC title

• B29L2031/3082

  Fuselages · CPC title

• B29D99/0014 Primary

  provided with ridges or ribs, e.g. joined ribs · CPC title

• B64C2001/0072

  from composite materials · CPC title