Systems, methods, and devices for light-weight PI-joints

Abstract

A device, such as a structural pi-joint, includes a first member extending along a first longitudinal axis and configured to couple to a first portion of a primary structure. The device includes a second member extending along a second longitudinal axis between the first portion and a second portion of the primary structure, the second longitudinal axis being substantially perpendicular to the first longitudinal axis, wherein the structural joint is a contiguous joint formed from a first material wherein each element is integrally formed with each adjacent element via an additive manufacturing device.

Description

SYSTEMS, METHODS, AND DEVICES FOR LIGHT-WEIGHT PI- JOINTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 632.670, filed April 11, 2024, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] The present disclosure relates generally to joints for coupling or supporting a structure (e.g., pi-joints for aerospace applications).

[0003] Aerospace structures are ty pically constructed using mechanical fasteners. Increasing the weight of the structure, creating stress concentration areas, and reducing aerodynamic properties of the structures are among the major downsides of using mechanical fasteners in aerospace applications. However, the adoption of load-bearing bonded joints presents significant opportunities for reducing both costs and weight in aircraft structures, provided that the associated challenges of meeting structural performance criteria, ensuring robust manufacturing processes, and conducting non-destructive inspections can be successfully addressed. Recent developments in aircraft structural bonded joint configurations include profiles such as 'Pi,' 'T,' and 'H' shapes. The applications of these profiles have been significantly increasing in recent years in the aerospace industry. The current standard of structural bonded joint design involves the use of metal alloys, such as aircraft aluminum. While this approach has seen success in pi, T. and H bonded joint configurations, their fabrication process is often cumbersome and expensive (due to the need for machining).

[0004] Furthermore, existing devices fail to provide for design optimization, enhanced manufacturing processes, advanced materials, or weight reduction of the pi-joint while maintaining strength. Therefore, a need exists to improve these joining components.SUMMARY

[0005] One implementation of the present disclosure is a structural j oint for supporting a portion of an aerospace assembly. The structural joint includes a first member extending along a first longitudinal axis and configured to couple to a first portion of a primarystructure. The structural joint further includes a second member extending along a second longitudinal axis between the first portion and a second portion of the primary structure, the second longitudinal axis being substantially perpendicular to the first longitudinal axis. The structural joint is a contiguous joint formed from a first material wherein each element is integrally formed with each adjacent element via an additive manufacturing device.

[0006] In some implementations, the first material is a carbon fiber composite material.

[0007] In some implementations, the first material is a polyetherimide (PEI) thermoplastic material.

[0008] In some implementations, the first and second members together form a pi-joint.

[0009] According to another implementation, in a pi joint for supporting a portion of an aerospace assembly including: a pi-shaped form including a first member, a second member, and a third member, wherein the first member is perpendicular to each of the second and third members, wherein the second and third members are parallel and spaced apart from each other to form a cavity; a web member disposed in the cavity of the pi-shaped form and adhered via an adhesive; a foot member perpendicular to the web member and coupled to a distal surface of the first member of the pi-shaped form via an adhesive; and an overwrap extending across each of the first and second members and the first and third members of the pi-shaped form, an improvement is disclosed wherein the pi joint is a continuous joint formed from a single material wherein each of the elements of the pi joint is integrally formed with each other.

[0010] In some implementations, the single material is a carbon fiber composite material.

[0011] In some implementations, the single material is a polyetherimide (PEI) thermoplastic material.

[0012] In some implementations, a method of manufacturing a structural joint for supporting a portion of an aerospace assembly is disclosed. The method includes generating a three-dimensional model based on dimensional data from a primary structure. The method further includes printing, via an additive manufacturing process with an additive manufacturing device, the structural j oint including: a first member extending along a first longitudinal axis and configured to couple to a first portion of the primary7structure; and a second member extending along a second longitudinal axis between the first portion and a second portion of the primary structure, the second longitudinal axis being substantially perpendicular to the first longitudinal axis. The structural joint is a contiguous joint formedfrom a first material wherein each element is integrally formed with each adjacent element via the additive manufacturing device.

[0013] In some implementations, the structural joint is a pi joint for supporting a portion of an aerospace assembly.

[0014] In some implementations, the method further includes coupling the structural joint to a surface of the primary structure.

[0015] In some implementations, the second member is coupled to the first portion of the primary structure via an adhesive material.

[0016] In some implementations, the second member is coupled to the first portion of the primary structure via at least one fastener.

[0017] In some implementations, the structural joint is a first structural joint and the three- dimensional model is a first three-dimensional model. The method further includes automatically updating the first three-dimensional model of the structural joint based on changes in dimensional data of the primary structure to produce a second three-dimensional model.

[0018] In some implementations, the method further includes automatically sending the second three-dimensional model to the additive manufacturing device, and printing, via a second additive manufacturing process, a second structural joint that is geometrically different from the first structural joint.

[0019] In some implementations, the first material is a carbon fiber composite material.

[0020] In some implementations, the first material is a polyetherimide (PEI) thermoplastic material.

[0021] Additional advantages will be set forth in part in the description that follows or may be learned by practice. The advantages will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive, as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a cross-sectional view of a traditional pi joint.

[0023] FIG. 2 is a picture of two 3D printed pi joints of the present disclosure, according to one implementation.

[0024] FIG. 3 is an isometric view of a 3D printed pi joint of the present disclosure, according to one implementation.

[0025] FIG. 4 is a top view of the pi j oint of FIG. 3.

[0026] FIG. 5 is a front view of the pi joint of FIG. 3.

[0027] FIG. 6 is a side view of the pi joint of FIG. 3.

[0028] FIG. 7 shows a graph of experimental results of a 3D printed lightweight pi joint compared to traditional geometry' pi joints.

[0029] Various objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the detailed description taken in conjunction with the accompanying drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements.DETAILED DESCRIPTION

[0030] Traditionally, a “pi-joint” facilitates a structural connection between two components at a right angle. A pi -joint is named due to the shape (the Greek letter “n”); however, other similar configurations are possible (e.g., T-joints or H-joints). These structural connections are often used in mechanically joining parts of a larger assembly (e.g.. an aircraft wing). In some examples, pi-joints are used in place of more traditional fasteners (e.g., rivets) that may produce a large stress concentration in the larger assembly. Thus, the pi -joints may be bonded to an interior surface of the larger assembly via adhesive and other laminate layers.

[0031] The structure of a traditional pi-joint includes a pi-shaped form 10, a foot member 20, a web member 30, an overwrap 40, and adhesive. For example, see FIG. 1, showing a cross-sectional view of a traditional pi-joint 10. The pi-shaped form 10 includes a first member 12, shown as a horizontal or foot member. The pi-joint further includes a second member 14 and a third member 16, shown as vertical members, extending from the first member 12 at a right angle. A cavity 18 is defined between the second and third members 14, 16.

[0032] The pi-shaped form 10 is coupled to the foot member 20 via an adhesive layer 50.The foot member 20 may be a structural component, such as an inner surface of a wing orother larger assembly. In some implementations, the foot laminate may be an intermediate material coupled to the larger assembly.

[0033] The web member 30 extends vertically from the foot member 20 and is disposed in the cavity 18 formed by the vertical members 14, 16 of the pi form 10. The web member 30 is coupled to each of the vertical members 14, 16, and the first member 12 of the pi form 10 by an adhesive layer 52.

[0034] The overwraps 40 are coupled to the pi form 10 and extend between both the vertical and the horizontal portions of the pi form 10. For example, a first side of the overwrap 40 extends from the adhesive layer 50 over the foot member 20, over a portion of the first member 12 of the pi form 10, over the second member 14 of the pi form 10, and over a portion of the adhesive layer 52 over the web member 30. The overwraps provide additional structure and support to the overall assembly.

[0035] The resulting assembly, as shown in FIG. 1, may be installed such that the web member 30 extends betw een opposing surfaces of a larger assembly (e.g., an upper and low er surface of the interior of an airplane wing). However, the traditional pi joint 10 shown in FIG. 1 includes multiple layers of material that may be susceptible to delamination and decoupling. Additionally, the manufacturing and installation process is cumbersome and time-consuming, and the design may not be adapted to all situations.Example Device and Manufacture

[0036] Described herein is a novel lightweight pi-joint, which is scalable and applicable to a variety of aerospace joining applications. According to some implementations, the disclosed device is manufactured via additive manufacturing (3D printing). According to some implementations, the additive manufacturing technique exhibits approximately a 12% decrease in weight compared to traditional design (not including additional reductions possible through geometry optimization), while maintaining the same mechanical properties (e.g. strength). In addition, computer simulations ensured that the disclosed device remained within the safe load and stress ranges when its geometry’ was optimized to reduce the raw material consumption and consequently decrease the total weight of the part (known as a lightweight structural design).

[0037] In some implementations, the device includes carbon fiber composite material (e.g., 3D printed carbon fiber composite material). In other implementations, the device includes a polyetherimide (PEI) thermoplastic material. For example, the device may include 3D-printedPEI materials, such as Ultem® 9085 or Ultem® 1010, which are already available for aerospace applications. Such PEI materials comply with National Institute for Aviation Research (NIAR) regulations.

[0038] In general, polyetherimide (PEI) thermoplastic material is known for its high strength, heat resistance, and flame retardancy, making it useful in the aerospace, automotive, medical, and electronics industries. For example, the PEI materials of the disclosed device (e.g., Ultem® 9085 or Ultem® 1010) can withstand continuous use at temperatures up to 217°C (422°F). The materials of the disclosed device are flame, smoke, and toxicity (FST) compliant such that they meet FAA FAR 25.853 standards for aerospace interiors. The materials of the disclosed device are resistant to various solvents, acids, and hydrocarbons.

[0039] The disclosed device and method of manufacturing the device provides several advantages over existing structures and processes, including but not limited to the following:

[0040] Weight reduction (lightweight design and manufacturing): Reducing the weight of an aircraft is important for several reasons, and while specific statistical values can vary depending on the aircraft type and mission, the general principles hold true across the aerospace industry. Furthermore, the lightweight design provides advantages for handling and installation.

[0041] Integrity and robustness of the joint: Aircraft operate in dynamic and high-stress environments. The integrity of joints and fasteners ensures the structural safety of the aircraft. Failure of a joint or fastener can result in catastrophic structural damage or even a crash.

[0042] Using advanced manufacturing techniques (e.g. 3D printing): 3D printing allows for the creation of complex, lightw eight structures with intricate internal geometries that are difficult or impossible to achieve using traditional manufacturing methods. For example, the disclosed device may be manufactured and customized to fit within the wing space of an aircraft. Such designs are scalable to a variety of wing sizes and shapes. Additive manufacturing techniques also reduce the weight of aerospace components, w hich improves fuel efficiency and overall performance.

[0043] Material Selection: Carbon fiber composites are known for their exceptional strength-to-weight ratio. Carbon fiber composites are significantly lighter than metal, which can lead to significant fuel savings for aircraft. This characteristic enhances the structural integrity of aerospace components. Carbon fiber composites are also more resistant to fatigue than metal, w hich can extend the lifespan of aircraft components. Furthermore, in the case ofpoly etherimide (PEI) thermoplastic material, similar advantages of heat resistance, lightweight design, strength-to-weight ratio, chemical resistance, and structural integrity are realized. The use of PEI materials (e.g., Ultem® 9085 or Ultem® 1010) in the 3D printed pi- joint disclosed herein has been validated for compliance, safety, and structural integrity, ensuring its suitability7for aerospace applications under NIAR regulations.

[0044] In-place inspection'. By providing a single-structure joint, rather than traditional layers of structure and adhesive, inspection is easier and more efficient. For example, rather than inspecting the part for delamination, which may be difficult to determine, the improved device needs only to be inspected for more obvious defects (e.g., cracks). Additionally, the overall number of parts to inspect is reduced.

[0045] The devices and joints (e.g., pi-joints) disclosed herein have applicability in industries beyond aerospace alone. It is understood that the described processes, structure, and advantages apply to various use cases. The disclosed 3D joints are lightweight, strong, and fatigue-resistant. The use of 3D printing provides for a dynamic design that can be used in a variety of scenarios and structures. For example, the disclosed 3D-printed joints can be used in a variety of aerospace applications, including connecting aircraft components, such as the wings and fuselage. In some implementations, the 3D-printed joints can be used in a variety of automotive applications, such as connecting suspension components and steering linkages. In some implementations, the 3D-printed joints can be used in a variety of marine applications, such as connecting sails to masts and rudders to hulls. In some implementations, the 3D-printed joints can be used in a variety of medical applications, such as connecting prosthetic limbs to bodies and surgical instruments to patients. In some implementations, the 3D-printed joints can be used in a variety of industrial applications, such as connecting robots to arms and machinery to components.

[0046] FIG. 2 shows an example image of two prototype 3D printed pi-joints comprising a carbon fiber composite material. As shown, the overall shape and dimensions approximate the overall shape and dimensions of the traditional pi -joint shown in FIG. 1. However, the pi joint shown in FIG. 2 is manufactured as a single, continuous component with carbon fiber composite material. Rather than rely on several layers of adhesive and overwrap, the pi joint of FIG. 2 is formed as a single, solid piece ready to be fit into a larger assembly (e.g., an airplane wing). In other implementations, the pi joint disclosed herein may include alternatives to carbon fiber composite materials, such as fiberglass-reinforced polymers (FRPs) or aramid fiber composites (e.g.. Kevlar). These materials offer similar benefits tocarbon fiber composites in terms of lightweight construction, high strength, and durability. Additionally, certain applications may benefit from the use of hybrid composite materials, which combine different fibers or matrices to achieve specific performance characteristics. For example, a pi joint could be manufactured using a combination of carbon fibers and glass fibers to optimize cost-effectiveness without compromising mechanical properties.

[0047] FIG. 3 shows an isometric view of a pi joint 100 of the present disclosure, according to one implementation. FIGS. 4-6 show other views of the pi joint 100. As shown, pi joint 100 includes a first member 120 extending along a first longitudinal axis and a second member 140 extending along a second longitudinal axis, wherein the first and second longitudinal axes are substantially perpendicular to each other. The first member 120 may be a horizontal component, and the second member 140 may be a vertical member.

[0048] As compared to the traditional pi -joint of FIG. 1, the overwrap element and the adhesive elements are not separate components but are instead integrally formed with the first and second members 120, 140 of the pi joint 100. Thus, the second member 140 includes a proximal portion 160 closer to the first member 120 and a distal portion 180 further from the first member 120. The proximal portion 160 of the second member 140 has a thickness larger than the thickness of the distal portion 180. How ever, in other implementations, the second member may have a continuous thickness.

[0049] The first member 120 also includes a proximal portion 200 closer to the second member 140 and a distal portion 220 farther from the second member 14. The proximal portion 200 of the first member 120 extends across the width of the pi joint, but the distal portion 220 of the first member 120 splits into two opposing leg members 240a and 240b.

[0050] The pi joint 100 may be manufactured from a carbon fiber composite material using an additive manufacturing process. For example, the pi joint 100 may be manufactured from a 3D printer capable of printing carbon fiber composite materials. In other implementations, the pi joint may be manufactured with poly etherimide (PEI) thermoplastic material compatible with aerospace applications. In some implementations, the 3D printer used for manufacturing the disclosed device is a Stratasys Inc. Fortus® 900mc Machine, Fortus® 450mc Machine, or similar additive manufacturing device. The disclosed device is printed with repeatability and consistency meeting the requirements of FAA AC 20-107B guidelines for additive manufactunng in aircraft structures.

[0051] The pi joint 100 is 3D printed with a size and / or dimensions matching a desired larger assembly. For example, the pi joint 100 may be manufactured to fit within a wing of an aircraft to provide inner support between opposing surfaces.

[0052] The exact length, width, and height of the pi joint 100, including its individual elements, may be determined based on the larger structure within which it will be installed. For example, a model of the pi joint 100 may be created to match the exact size and shape of a wing cavity . The manufacturing process for the pi joint of this disclosure may also include analyzing or inputting data from the larger assembly (e.g., an airplane wing) to create a model of the pi joint matching the dimensions of the larger assembly. For example, a model of the pi joint may be automatically7created, via a computer program, based on the given dimensions of the larger assembly. In some implementations, the computer program (or other controller providing the customized design of the pi joint) is in communication with a 3D printer to automatically7manufacture the customized pi joint from a carbon fiber composite matenal.

[0053] In some implementations, the second member may extend vertically from the first member by a ratio much larger than that shown in FIG. 3. In some implementations, the pi joint may have some sections with a dimension (e.g., a height) larger or smaller than a corresponding dimension of another section (e.g., the pi joint may be shaped to fit a narrowing portion of a wing cavity7wherein one end of the pi joint has a height relatively smaller than the height on another end of the pi joint). In some implementations, the pi joint may have a third member, substantially similar to the first member, extending perpendicular to the second member at a distal end thereof (e.g., forming an I-joint or an H-joint).

[0054] The pi joint 100 is installed in the larger assembly using an adhesive on the bottom surface of the first member 120. The second member 140 may also have an adhesive applied to the distal surface to bond the second member 140 of the pi joint 100 to an opposing surface of the larger assembly. However, in other implementations, the first member of the pi joint is coupled to a portion of the larger assembly via a fastener (e.g., a bolt or rivet).Experimental Study and Results

[0055] The disclosed 3D-printed pi joint provides strength and fatigue properties matching or exceeding that of traditional pi joints. For example, FIG. 7 shows a graph of loading vs displacement for three different tests. A study was conducted using a prototy pe 3D printed lightweight pi joint alongside traditional geometry pi joints. As shown, the prototype 3D printed pi joint comprising carbon fiber composite material had a rigidity, yield strength, andultimate strength higher than that of a traditional pi joint. Major outcomes from the results in FIG. 7 are: (1) 3D printed pi joint shows higher resiliency (the ability of a material to absorb energy when it is deformed elastically, and release that energy upon unloading); (2) 3D printed pi joint shows at least the same (and even slightly higher) rigidity (a material's resistance to bending); and (3) 3D printed pi joint shows at least the same (and even slightly higher) yield strength (the maximum stress a material will tolerate before plastic deformation begins). These outcomes show that the 3D-printed pi joint not only meets but also improves the mechanical performance of the pi joints.Configuration of Certain Implementations

[0056] The construction and arrangement of the systems and methods as shown in the various implementations are illustrative only. Although only a few implementations have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes, and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative implementations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the implementations without departing from the scope of the present disclosure.

[0057] The present disclosure contemplates methods, systems, and program products on any machine-readable media for accomplishing various operations. The implementations of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Implementations within the scope of the present disclosure include program products including machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine- readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures, and which can be accessed by a general purpose or special purpose computer or other machine with a processor.

[0058] When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general-purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

[0059] Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Also, tw o or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the softw are and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps.

[0060] It is to be understood that the methods and systems are not limited to specific synthetic methods, specific components, or to particular compositions. It is also to be understood that the terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting.

[0061] As used in the specification and the appended claims, the singular forms ‘"a,” "‘an7’ and “the’’ include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another implementation includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another implementation. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0062] “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where saidevent or circumstance occurs and instances where it does not. Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as “comprising’’ and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps. “Exemplary” means “an example of’ and is not intended to convey an indication of a preferred or ideal implementation. “Such as” is not used in a restrictive sense, but for explanatory purposes.

[0063] Disclosed are components that can be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutation of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods and systems. This applies to all aspects of this application including, but not limited to, steps in disclosed methods. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific implementation or combination of implementations of the disclosed methods.

Claims

WHAT IS CLAIMED IS:

1. A structural joint for supporting a portion of an aerospace assembly comprising: a first member extending along a first longitudinal axis and configured to couple to a first portion of a primary structure; and a second member extending along a second longitudinal axis between the first portion and a second portion of the primary structure, the second longitudinal axis being substantially perpendicular to the first longitudinal axis, wherein the structural j oint is a contiguous joint formed from a first material wherein each element is integrally formed with each adjacent element via an additive manufacturing device.

2. The structural joint of claim 1, wherein the first material is a carbon fiber composite material.

3. The structural joint of claim 1, wherein the first material is a polyetherimide (PEI) thermoplastic material.

4. The structural joint of claim 1, wherein the first and second members together form a pi- joint.

5. In a pi joint for supporting a portion of an aerospace assembly comprising: a pi-shaped form comprising a first member, a second member, and a third member, wherein the first member is perpendicular to each of the second and third members, wherein the second and third members are parallel and spaced apart from each other to form a cavity; a web member disposed in the cavity of the pi-shaped form and adhered via an adhesive; a foot member perpendicular to the web member and coupled to a distal surface of the first member of the pi-shaped form via an adhesive; andan overwrap extending across each of the first and second members and the first and third members of the pi-shaped form, an improvement wherein the pi joint is a continuous joint formed from a single material wherein each of the elements of the pi joint is integrally formed with each other.

6. The pi joint of claim 5, wherein the single material is a carbon fiber composite material.

7. The pi joint of claim 5, wherein the single material is a polyetherimide (PEI) thermoplastic material.

8. A method of manufacturing a structural j oint for supporting a portion of an aerospace assembly, the method comprising: generating a three-dimensional model based on dimensional data from a primary structure; and printing, via an additive manufacturing process with an additive manufacturing device, the structural joint comprising: a first member extending along a first longitudinal axis and configured to couple to a first portion of the primary structure; and a second member extending along a second longitudinal axis between the first portion and a second portion of the primary structure, the second longitudinal axis being substantially perpendicular to the first longitudinal axis, wherein the structural joint is a contiguous joint formed from a first material wherein each element is integrally formed with each adjacent element via the additive manufacturing device.

9. The method of claim 8, wherein the structural joint is a pi joint for supporting a portion of an aerospace assembly.

10. The method of claim 8, further comprising: coupling the structural joint to a surface of the primary structure.

11. The method of claim 10, wherein the second member is coupled to the first portion of the primary structure via an adhesive material.

12. The method of claim 10, wherein the second member is coupled to the first portion of the primary structure via at least one fastener.

13. The method of claim 8, wherein the structural j oint is a first structural joint and the three- dimensional model is a first three-dimensional model, the method further comprising: automatically updating the first three-dimensional model of the structural joint based on changes in dimensional data of the primary structure to produce a second three-dimensional model.

14. The method of claim 13, further comprising: automatically sending the second three-dimensional model to the additive manufacturing device; and printing, via a second additive manufacturing process, a second structural joint that is geometrically different from the first structural j oint.

15. The method of claim 8, wherein the first material is a carbon fiber composite material.

16. The method of claim 8, wherein the first material is a polyetherimide (PEI) thermoplastic material.

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