System and method for forming flanges in composite fan containment cases

Abstract

A system for manufacturing a composite fan containment case may include a mold defining a body portion corresponding to a fan containment case, the mold including an extended removable surface disposed adjacent an end of the body portion. The system may further include an automated fiber placement machine configured to place composite material onto the mold, the composite material extending across the body portion and the extended removable surface. The system may further include a reverse flange forming structure positioned adjacent the end of the body portion after removal of the extended removable surface and an end effector associated with the automated fiber placement machine. The end effector may be configured to apply pressure to an unsupported portion of the composite material extending beyond the body portion so as to progressively fold the composite material against the reverse flange forming structure and form an integral attachment flange.

Description

Docket No. MRA105WOSYSTEM AND METHOD FOR FORMING FLANGES IN COMPOSITE FAN CONTAINMENT CASESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Application No. 63 / 779,423 filed March 28, 2025, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] Composite fan containment cases are widely used in aerospace applications due to their favorable strength-to-weight characteristics and ability to withstand high-energy impact events. Many composite fan cases currently deployed in commercial aircraft are manufactured using resin infusion-based processes, including bulk resin infusion and resin transfer molding techniques.

[0003] In such processes, dry fiber preforms (often formed from two-dimensional or multi-dimensional woven fabrics, blankets, or braided reinforcements) are wrapped around a mold to define the fan case geometry. After the preform is assembled, the mold is enclosed or bagged and a liquid matrix resin is introduced under pressure to permeate the fiber architecture, followed by a curing operation. Because the reinforcing fibers are not pre-impregnated with resin during preform formation, these dry fiber materials may be shaped into attachment features, such as flanges, prior to resin infusion. In many cases, however, such integrated flanges require post-cure machining to achieve desired dimensional tolerances and surface finishes.

[0004] While resin infusion techniques can enable the formation of integrated attachment flanges, these processes are often complex, capital-intensive, and difficult to industrialize. The handling and control of liquid resin systems can introduce manufacturing variability and require additional equipment and process controls, which may increase production cost and cycle time.

[0005] By contrast, prepreg-based composite manufacturing techniques utilize reinforcing fibers that are pre-impregnated with a matrix material prior to layup. As used herein, the term “prepreg” may refer to a composite material in which reinforcing fibers are pre-impregnated with a matrix resin prior to layup. As used herein, “layup” refers to placing composite material onto a mold to define a part geometry prior to curing, including automated placement ofDocket No. MRA105WOcomposite tapes or tows using an automated fiber placement machine. The resin is typically partially cured so that the material may be handled and placed in a controlled manner and is subsequently fully cured under heat and pressure to form a finished composite structure.Automated fiber placement (AFP) systems have been developed to place prepreg materials onto molds using robotic heads, enabling automated and repeatable composite layup without the need to manage liquid resin during part formation. However, conventional prepreg and AFP manufacturing approaches have historically presented challenges in forming integral attachment flanges, particularly where the geometry requires significant fiber reorientation or out-of-plane forming.

[0006] Accordingly, there remains a need for improved manufacturing methods that enable the efficient formation of composite fan containment cases using prepreg materials and automated placement technologies, while also providing integral attachment flanges with desirable structural and mechanical properties, reduced manufacturing complexity, and improved production efficiency.BRIEF SUMMARY

[0007] At least an exemplary embodiment of a system for manufacturing a composite fan containment case may include a mold defining a body portion corresponding to a fan containment case, the mold including an extended removable surface disposed adjacent an end of the body portion. The system may further include an automated fiber placement machine configured to place composite material onto the mold, the composite material extending across the body portion and the extended removable surface. The system may further include a reverse flange forming structure positioned adjacent the end of the body portion after removal of the extended removable surface and an end effector associated with the automated fiber placement machine. The end effector may be configured to apply pressure to an unsupported portion of the composite material extending beyond the body portion so as to progressively fold the composite material against the reverse flange forming structure and form an integral attachment flange.

[0008] At least an exemplary embodiment of a method of manufacturing a composite fan containment case may include placing composite material onto a mold defining a body portion of a fan containment case, the mold including an extended removable surface such that the composite material extends beyond an end of the body portion onto the extended removable surface. The method may further include removing the extended removable surface afterDocket No. MRA105WOplacement of the composite material, thereby leaving an unsupported portion of the composite material extending beyond the end of the body portion. The method may further include positioning a reverse flange forming structure adjacent the end of the body portion. The method may further include applying pressure to the unsupported portion of the composite material using an end effector of an automated fiber placement machine so as to progressively fold the composite material against the reverse flange forming structure and form an integral attachment flange at the end of the fan containment case.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009] A more particular description will be rendered by reference to exemplary embodiments that are illustrated in the accompanying figures. Understanding that these drawings depict exemplary embodiments and do not limit the scope of this disclosure, the exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0010] FIG. l is a perspective view of a system for forming flanges according to an exemplary embodiment;

[0011] FIG. 2A shows a system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0012] FIG. 2B shows a system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0013] FIG. 2C shows a system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0014] FIG. 2D shows a system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0015] FIG. 3A shows a schematic block diagram of system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0016] FIG. 3B shows a schematic block diagram of system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0017] FIG. 3C shows a schematic block diagram of system for forming flanges at a stage in a forming process according to an exemplary embodiment;

[0018] FIG. 3D shows a schematic block diagram of system for forming flanges at a stage in a forming process according to an exemplary embodiment;Docket No. MRA105WO

[0019] FIG. 4 is a perspective view of a fan containment case according to an exemplary embodiment; and

[0020] FIG. 5 is a flowchart of a method for forming a fan containment case according to an exemplary embodiment.

[0021] Various features, aspects, and advantages of the exemplary embodiments will become more apparent from the following detailed description, along with the accompanying drawings in which like numerals represent like components throughout the figures and detailed description. The various described features are not necessarily drawn to scale in the drawings but are drawn to aid in understanding the features of the exemplary embodiments.

[0022] The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.DETAILED DESCRIPTION

[0023] Reference will now be made in detail to various exemplary embodiments. Each example is provided by way of explanation and is not meant as a limitation and does not constitute a definition of all possible embodiments. To the extent that the description or figures refer to a specific dimension, orientation, or direction of a component, it will be understood that these are for illustrative purposes and not intended to be limiting. It is understood that reference to a particular “exemplary embodiment” of, e.g., a structure, assembly, component, configuration, method, etc. includes exemplary embodiments of, e g., the associated features, subcomponents, method steps, etc. forming a part of the “exemplary embodiment.”

[0024] For purposes of this disclosure, the phrases “devices,” “systems,” and “methods” may be used either individually or in any combination referring without limitation to disclosed components, grouping, arrangements, steps, functions, or processes.

[0025] Referring to FIG. 1 shows an exemplary embodiment of a system 102 for manufacturing a composite fan containment case. The system 102 may include an automated fiber placement machine 104 having a robotic arm 106 configured to position one or more tools relative to a mold 112. The automated fiber placement machine 104 may be implemented in any suitable form, including but not limited to an articulated robotic arm, gantry-based system, carriage-based system, or other automated positioning architecture. The robotic arm 106 shown in FIG. 1 is provided as one non-limiting example.Docket No. MRA105WO

[0026] In the illustrated embodiment, the automated fiber placement machine 104 may carry an end effector 108 and one or more fiber placement tools 110. The fiber placement tools 110 may be configured to place composite material onto the mold 112 during a layup operation. The end effector 108 may be configured to directly engage composite material after layup and apply pressure during formation of an attachment flange, as described below.

[0027] As used herein, “end effector” may refer to a functional tool or tool assembly carried by the automated fiber placement machine 104 and configured to directly engage composite material. In some embodiments, the automated fiber placement machine 104 may carry multiple end effectors simultaneously, while in other embodiments a single integrated end effector may perform multiple functions. Depending on the embodiment, a fiber placement tool 110, a roller or pressure applicator, and / or a heating element may each be an end effector, a component of an end effector, or a separate tool carried by the automated fiber placement machine 104. These examples are non-limiting and are provided to clarify that “end effector” is a functional designation rather than a requirement that specific components be integrated into a single physical structure.

[0028] An end effector 108 being “associated with” the automated fiber placement machine 104 is intended to be broad and non-limiting. By way of example and not limitation, the end effector 108 may be directly mounted to the robotic arm 106 or a head; coupled via a tool-changer or quick-disconnect interface; mounted to or carried by an intermediate carriage, slide, gimbal, or compliance mechanism; integrated into a modular head assembly; indirectly supported by intermediate structures; and / or operatively coupled via force-transmission linkages. These examples are provided to exemplify scope and avoid any implication that the phrase “associated with” indicates any specific type of connection or mounting.

[0029] The mold 112 may be configured to define a shape of a composite fan containment case 114. For example, the mold 112 may be used to shape a body portion 116 of the fan containment case 114. In an exemplary embodiment, an extended removable structure 118 may be disposed adjacent an end 302 of the mold 112 (see FIG. 3A). An outer circumferential surface 120 of the extended removable structure 118 may be formed as a ring-shaped structure, an annulus, a solid cylinder, or other suitable shape. The outer circumferential surface 120 of the extended removable structure 118 may support deposition of material during layup that will be formed into the attachment flange 202 (see FIG. 2D and FIG. 4). Following removal of the extended removable structure 118, the material formed against the outer circumferential surfaceDocket No. MRA105WO120 will remain as an unsupported portion 124 integrated with the body portion 116 shaped by the mold 112.

[0030] A backstop 122 (also referred to as a reverse flange forming structure) may be disposed around the body portion 116 of the fan containment case 114 during forming operations. The backstop 122 may be shaped as an annulus and positioned at a boundary between the body portion 116 and the unsupported portion 124 of the fan containment case 114. The backstop 122 may define a forming surface 126 against which composite material may be folded to form an attachment flange 202. In some embodiments, the backstop 122 may be a structure separate from the mold 112, while in other embodiments it may be mountable, removable, replaceable, adjustable, or otherwise configurable relative to the mold 112 and / or the fan containment case 114.

[0031] FIGS. 2A-2D illustrate successive stages of composite layup and preparation for flange formation. Referring to FIG. 2A, composite material may be placed onto the mold 112 using the automated fiber placement machine 104 and fiber placement tool(s) 110. The composite material may be laid such that it forms the body portion 116 of the composite fan containment case 114 and extends onto the outer circumferential surface 120 of the extended removable structure 118.

[0032] After placement of the composite material, the extended removable structure 118 may be removed, as illustrated in FIG. 2B. Removal of the extended removable structure 118 leaves the unsupported portion 124 of composite material extending from an end of the body portion 116. The unsupported portion 124 is no longer supported by the mold 112 and is positioned for subsequent forming operations.

[0033] In an exemplary embodiment, the unsupported portion 124 may comprise a circumferential or annular extension of composite material, although other geometries are possible depending on the part configuration. The unsupported portion 124 is the portion of composite material that may be subsequently formed into the integral attachment flange.

[0034] FIGS. 2C-2D illustrate successive stages of forming an attachment flange 202 from the unsupported portion 124 of composite material. With the backstop 122 positioned at a boundary between the body portion 116 and the unsupported portion 124, the end effector 108 may be brought into engagement with the unsupported portion 124 to apply pressure to the unsupported portion 124. In the embodiment of FIG. 2C, the end effector 108 is illustrated only, but it will be understood that this is for exemplary purposes only and is not intended to beDocket No. MRA105WOlimited. The end effector 108 may be embodied as any suitable tool for applying pressure and / or shaping the unsupported portion 124.

[0035] As shown in FIG. 2C, the end effector 108 may apply pressure to progressively fold and / or shape the unsupported portion 124 toward and against the backstop 122. In some embodiments, the end effector 108 may include a roller or pressure applicator 308 configured to apply forming pressure. The forming operation may be performed in a single pass or over a plurality of passes, with the end effector 108 progressively working the unsupported portion 124 into conformance with the forming surface 126 defined by the backstop 122.

[0036] As shown in FIG. 2D, continued application of pressure via the end effector 108 may cause the unsupported portion 124 to be folded against the forming surface 126 of the backstop 122 to form the attachment flange 202 of the composite fan containment case 114. The attachment flange 202 may be formed integrally with the body portion 116 (i.e., from the same laid-up composite material), rather than being attached as a separately fabricated component.

[0037] In some embodiments, the attachment flange 202 may be formed at one end of the composite fan containment case 114, while in other embodiments attachment flanges may be formed at opposite ends of a fan containment case. Further, while some embodiments may involve folding the unsupported portion 124 to approximately a right angle relative to the body portion 116, the flange geometry is not limited to any particular angle. By way of non-limiting example, the flange angle may be less than, equal to, or greater than 90 degrees, depending on design requirements.

[0038] FIGS. 3A-3D provide schematic block representations of the forming process illustrated in FIGS. 2 A 2D. These figures illustrate functional relationships and process stages and do not limit the physical configuration or sequence of operations.

[0039] FIG. 3A shows a schematic configuration following layup of the composite material. For example, FIG. 3A shows the mold 112, the extended removable structure 118 positioned against the end 302 of the mold 112, and the body portion 116 and the unsupported portion 124 of the fan containment case 114. In FIG. 3B, the extended removable structure 118 has been removed and the backstop 122 has been positioned on an exterior of the fan containment case 114 (shown as the body portion 116 and the unsupported portion 124 in FIG. 3B). It will be understood that removal of the extended removable structure 118 is not required for positioning the backstop 122. In other words, the backstop 122 may be positioned before, simultaneous with, or after removal of the extended removable structure 118.Docket No. MRA105WO

[0040] FIG. 3C schematically illustrates application of heat 306 to the unsupported portion 124 using a heating element 304. The heating element 304 may be associated with the automated fiber placement machine 104 and may be integrated into the end effector 108 (e.g., integrated into a heated roller), or provided as a separate heating device carried by the automated fiber placement machine 104. Heating may be optional and may be omitted in certain embodiments. When used, heating may begin before application of pressure and may continue during application of pressure. In the embodiment of FIG. 3C, the heating element 304 is illustrated as a radiant heat traversing space between the heating element 304 and the unsupported portion 124, but it will be understood that the disclosure is not limited to this embodiment. For example, in an embodiment in which the heating element 304 is incorporated within the end effector 108 (e.g., a heated roller), heat may be transferred directly from the heating element 304 via contact and conduction.

[0041] FIG. 3D schematically illustrates application of pressure to the unsupported portion 124 using a pressure applicator 308 associated with the end effector 108, thereby folding the unsupported portion 124 against the backstop 122. The pressure applicator 308 may be a roller or other suitable tool for applying pressure to the unsupported portion 124.

[0042] FIG. 4 illustrates a composite fan containment case 114 having a body portion 116 and an attachment flange 202 formed at an end of the body portion 116.

[0043] In some embodiments, after the attachment flange 202 has been formed, the automated fiber placement machine 104 may apply additional composite material onto a mating surface of the attachment flange 202. This optional post-forming application may be used to modify or enhance structural characteristics of the flange (e.g., stiffness, strength, thickness, load transfer, fatigue resistance, or impact resistance). This application may be performed at one flange, multiple flanges, or selected regions and is non-limiting.

[0044] FIG. 5 illustrates a flowchart of an exemplary method 500 for forming an attachment flange. In block 502, a mold such as the mold 112 is provided. As part of the block 502, the extended removable structure 118 may be provided adjacent to the mold. In block 504, the composite material is deposited against the mold 112, including the extended removable structure 118 (i.e., layup). In block 506, the extended removable structure 118 is removed, leaving the unsupported portion 124. In block 508, the backstop 122 may be positioned at a boundary between the body portion 116 and the unsupported portion 124 of the fan containment case 114. As noted above, the positioning of the backstop 122 is not required toDocket No. MRA105WOfollow removal of the extended removable structure 118, and positioning of the backstop 122 could occur before, simultaneous with, or after removal of the extended removable structure 118. In block 510, heat may be applied to the unsupported portion 124. In block 512, pressure may be applied to the unsupported portion 124 to fold and shape the unsupported portion 124 into the attachment flange 202. It will be understood that the application of the heat in block 510 may be applied before and / or continuously with the application of pressure in the block 512. It will be understood that the application of the pressure in block 512 may be performed in one pass or multiple passes.

[0045] In an exemplary embodiment, the composite material may include prepreg materials and / or other composite materials suitable for automated placement. By way of non-limiting example, the composite material may comprise thermosetting and / or thermoplastic composite materials and reinforcing fibers may include carbon fibers and / or other reinforcing fibers. These examples are non-limiting.

[0046] The phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C" and "A, B, and / or C" means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

[0047] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as "about" or “approximately” is not to be limited to the precise value specified. Such approximating language may refer to the specific value and / or may include a range of values that may have the same impact or effect as understood by persons of ordinary skill in the art field. For example, approximating language may include a range of + / - 10%, + / -5%, or + / -3%. The term “substantially” as used herein is used in the common way understood by persons of skill in the art field with regard to patents, and may in some instances function as approximating language. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value.

[0048] In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms "a" (or "an") and "the" refer to one or more of that entity, thereby including plural referents unless the context clearly dictatesDocket No. MRA105WOotherwise. As such, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. Furthermore, references to "one embodiment", "some embodiments", "an embodiment" and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as "about" is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as "first," "second," "upper," "lower" etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.

[0049] As used herein, the terms "may" and "may be" indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and / or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of "may" and "may be" indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur - this distinction is captured by the terms "may" and "may be."

[0050] As used in the claims, the word "comprises" and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, "consisting essentially of" and "consisting of." Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that the appended claims should cover variations in the ranges except where this disclosure makes clear the use of a particular range in certain embodiments.

[0051] The terms "determine", "calculate," and "compute," and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.

[0052] This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are groupedDocket No. MRA105WOtogether to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

[0053] Advances in science and technology may provide variations that are not necessarily express in the terminology of this disclosure although the claims would not necessarily exclude these variations.

Claims

Docket No. MRA105WOCLAIMSWhat is claimed is:

1. A system for manufacturing a composite fan containment case, the system comprising:a mold defining a body portion corresponding to a fan containment case, the mold including an extended removable surface disposed adjacent an end of the body portion;an automated fiber placement machine configured to place composite material onto the mold, including composite material extending across the body portion and the extended removable surface;a reverse flange forming structure positioned adjacent the end of the body portion after removal of the extended removable surface; andan end effector associated with the automated fiber placement machine, the end effector configured to apply pressure to an unsupported portion of the composite material extending beyond the body portion so as to progressively fold the composite material against the reverse flange forming structure and form an integral attachment flange at the end of the fan containment case.

2. The system of claim 1, wherein the extended removable surface is detachably coupled to the mold and is removable after placement of the composite material.

3. The system of claim 1, wherein the reverse flange forming structure is separate from the mold and defines a forming surface positioned to receive the composite material during formation of the attachment flange.

4. The system of claim 1, wherein the end effector is configured to progressively fold the composite material toward the reverse flange forming structure over a plurality of passes.

5. The system of claim 4, wherein the end effector comprises a roller configured to apply pressure to the composite material as the composite material is folded against the reverse flange forming structure.

6. The system of claim 1, further comprising a heating element configured to heat the composite material during formation of the attachment flange.Docket No. MRA105WO7. The system of claim 6, wherein the heating element is associated with the automated fiber placement machine.

8. The system of claim 1, wherein the composite material comprises a prepreg material.

9. The system of claim 8, wherein the prepreg material comprises a thermosetting composite material or a thermoplastic composite material.

10. The system of claim 1, wherein the automated fiber placement machine is further configured to apply additional composite material onto a mating surface of the attachment flange after formation of the attachment flange.

11. A method of manufacturing a composite fan containment case, comprising:placing composite material onto a mold defining a body portion of a fan containment case, the mold including an extended removable surface such that the composite material extends beyond an end of the body portion onto the extended removable surface;removing the extended removable surface after placement of the composite material, thereby leaving an unsupported portion of the composite material extending beyond the end of the body portion;positioning a reverse flange forming structure adjacent the end of the body portion; and applying pressure to the unsupported portion of the composite material using an end effector of an automated fiber placement machine so as to progressively fold the composite material against the reverse flange forming structure and form an integral attachment flange at the end of the fan containment case.

12. The method of claim 11, wherein the extended removable surface is detachably coupled to the mold and is removed after placement of the composite material.

13. The method of claim 11, wherein positioning the reverse flange forming structure comprises positioning a reverse flange forming structure that is separate from the mold and that defines a forming surface configured to receive the composite material during formation of the attachment flange.

14. The method of claim 11, wherein applying pressure comprises progressively folding the composite material toward the reverse flange forming structure over a plurality of passes.Docket No. MRA105WO15. The method of claim 14, wherein applying pressure comprises applying pressure using a roller of the end effector as the composite material is folded against the reverse flange forming structure.

16. The method of claim 11, further comprising heating the composite material during formation of the attachment flange.

17. The method of claim 16, wherein heating the composite material is performed using a heating element associated with the automated fiber placement machine.

18. The method of claim 11, wherein placing composite material comprises placing a prepreg material onto the mold.

19. The method of claim 18, wherein the prepreg material comprises a thermosetting composite material or a thermoplastic composite material.

20. The method of claim 11, further comprising applying additional composite material onto a mating surface of the attachment flange after formation of the attachment flange.

Images