Cell structure including reinforcement pattern

Abstract

Methods, apparatus, systems, and articles of manufacture are disclosed for a structure for an engine component, including a first plurality of cells offset from a neutral plane in a first direction, a second plurality of cells offset from the neutral plane in a second direction, a plurality of nodes connecting cells of the first plurality of cells and cells of the second plurality of cells, wherein the first plurality of cells and the second plurality of cells are arranged in pairs such that a cell of the first plurality of cells is laterally adjacent to and interconnected with a cell of the second plurality of cells, and wherein the structure is a reinforcement structure.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to gas turbines, and more particularly, to a cell structure including a reinforcement pattern. BACKGROUND

[0002] Gas turbine engines generally include, in serial flow order, an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air enters the inlet section and flows to the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section, producing combustion gases. The combustion gases flow from the combustion section through a hot gas path defined within the turbine section, and then exit the turbine section via the exhaust section.

[0003] Gas turbine engines, such as turbofan engines, include a bypass duct that completely or partially surrounds a core turbine engine of the turbofan engine, including a compressor section, a combustion section, a turbine section, and an exhaust section. Operation and orientation of the turbofan engine during flight of an aircraft can induce overturning moments, axial compression forces, and / or torsion on components and / or structures of the turbofan engine, such as the bypass duct, a fan casing, and / or a shroud, among others. SUMMARY

[0004] Methods, apparatus, systems, and articles of manufacture corresponding to a cell structure including a reinforcement pattern are disclosed.

[0005] Certain examples provide a structure of an engine component including a first plurality of cells offset from a neutral plane in a first direction. The example structure further includes a second plurality of cells offset from the neutral plane in a second direction. The example structure further includes a plurality of nodes joining cells of the first plurality of cells and cells of the second plurality of cells, wherein the first plurality of cells and the second plurality of cells are arranged in pairs such that a cell of the first plurality of cells is laterally adjacent to and interconnected with a cell of the second plurality of cells, and wherein the structure is a reinforcement structure.

[0006] Certain examples provide a structure surrounding a gas turbine including a first plurality of cells. The example structure further includes a second plurality of cells, the first plurality of cells offset from the second plurality of cells relative to a neutral plane to increase a moment of inertia of the structure, cells of the first plurality of cells alternating with cells of the second plurality of cells to define the structure such that the cells are laterally adjacent, and the first plurality of cells and the second plurality of cells offset from one another relative to a neutral plane defining a centerline through the structure. The example structure further includes a plurality of nodes joining the first plurality of cells with the second plurality of cells.

[0007] Certain examples provide a unit cell structure of an aircraft component, the unit cell structure including a first plurality of unit cells. The example unit cell structure also includes a second plurality of unit cells offset in a first direction from the first plurality of unit cells, the first plurality of unit cells and the second plurality of unit cells forming opposing surfaces, unit cells in the first plurality of unit cells alternating with unit cells in the second plurality of unit cells such that the unit cells are laterally adjacent, the first surface and the second surface offset from one another relative to a neutral plane that defines a centerline through the unit cell structure. The example unit cell structure also includes a plurality of nodes joining the first plurality of unit cells and the second plurality of unit cells to reinforce the unit cell structure.

[0008] Certain examples provide an additively manufactured unitized lattice structure, the additively manufactured unitized lattice structure including a first plurality of triangular unit cells disposed on a first side of a neutral plane for a curved unitized lattice structure. The example additively manufactured unitized lattice structure also includes a second plurality of triangular unit cells disposed on a second side of the neutral plane, the second side opposite the first side. The example additively manufactured unitized lattice structure also includes a plurality of nodes. The example additively manufactured unitized lattice structure also includes a plurality of transition edges, the plurality of nodes and the plurality of transition edges connecting the first plurality of unit cells and the second plurality of unit cells.

[0009] Certain examples provide an additively manufactured lattice structure, the additively manufactured lattice structure including a first plurality of square unit cells defining a first surface, the first plurality of square unit cells disposed on a first side of a neutral plane for a curved lattice structure. The example additively manufactured lattice structure also includes a second plurality of square unit cells defining a second surface, the second plurality of square unit cells disposed on a second side of the neutral plane opposite the first side, the second plurality of square unit cells joined to the first plurality of square unit cells by a plurality of (a) nodes intersecting the neutral plane and (b) transition edges intersecting the neutral plane. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a schematic cross-sectional view of an example high-bypass turbofan gas turbine engine.

[0011] FIG. 2 is a perspective view of a known conventional lattice structure.

[0012] Figure 3A is a perspective view of an example first panel including a reinforcement pattern for a unit cell structure.

[0013] Figure 3B is Figure 3A is a front view of the first panel of

[0014] Figure 4 is a perspective view of a first panel of Figure 3BThe AA cutting line is intercepted Figure 3A A cross section of the first panel.

[0015] Figure 5 It is along Figure 3B BB cutting line intercepted Figure 3A Another cross-section of the first panel.

[0016] Figure 6 yes Figure 3A Another perspective view of the first panel showing the reverse side of the first panel.

[0017] Figure 7 Is included for Figures 3A-6 A stereogram of an example cylindrical structure with a reinforcement pattern of a unit cell structure.

[0018] Figure 8A is a perspective view of an example second panel including a Figures 3A-7 The reinforcement pattern of the cell structure is replaced by nodes.

[0019] Figure 8B yes Figure 8A Front view of the second panel of FIG. 1 , showing an example cut line CC.

[0020] Figure 8C It is along Figure 8B The CC cutting line is intercepted Figure 8A A cross section of the second panel.

[0021] Figure 9A is included Figure 3A Front view of an example cylindrical structure model of the reinforcement pattern of the PDMS-8.

[0022] Figure 9B is included Figures 3A-8C Example of a reinforcement pattern. Front view of a cylindrical structure model where the size of the cells varies throughout the structure.

[0023] Figure 9C is included Figures 3A-8C Example of a reinforcement pattern. Front view of a cylindrical structure model where the geometry of the cell varies throughout the structure.

[0024] Figure 10 It is used for traditional grid structures and includes Figure 3A -Graph of the buckling coefficients of structures with a reinforcement pattern of 9.

[0025] Figure 11 Yes means including Figure 3A A flow chart of an exemplary method for assembling an aircraft component having a reinforcement pattern of a cell structure of -8.

[0026] Figure 12 is constructed to execute Figure 11 A block diagram of an example processor platform for instructions.

[0027] The drawings are not drawn to scale. Instead, the thickness of layers or regions may be exaggerated in the drawings. Generally, the same reference numerals will be used throughout the drawings and accompanying written descriptions to refer to the same or similar parts. As used in this patent, stating that any part (e.g., layer, film, region, area, or plate) is located in any way (e.g., positioned on, located on, arranged on, or formed on) another part means that the referenced part is in contact with the other part, or the referenced part is above the other part, with one or more intermediate parts located between them. Unless otherwise specified, connection references (e.g., attachment, coupling, connection, and engagement) should be interpreted broadly and may include intermediate members between a set of elements and relative movement between elements. Therefore, connection references do not necessarily infer that two elements are directly connected and have a fixed relationship to each other. Stating that any part is "in contact with" another part means that there are no intermediate parts between the two parts. Although the figures show layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In practice, boundaries and / or lines may be unobservable, mixed, and / or irregular.

[0028] When identifying multiple elements or components that can be mentioned individually, the descriptors "first," "second," "third," etc. are used herein. Unless otherwise specified or understood based on the context of their use, such descriptors are not intended to confer any meaning of priority, physical order or arrangement, or temporal ordering in a list, but are merely used as labels to refer to multiple elements or components, respectively, to facilitate understanding of the disclosed examples. In some examples, the descriptor "first" can be used to refer to an element in the detailed description, while the same element can be referred to by different descriptors (such as "second" or "third") in the claims. In such cases, it should be understood that such descriptors are only used to facilitate reference to multiple elements or components. DETAILED DESCRIPTION

[0029] Due to the thrust, orientation, and operation of a turbofan engine, during flight, overturning moments (e.g., bending moments), axial compression forces, and torsion are induced on a gas turbine engine, such as a turbofan engine of an aircraft. The overturning moments, axial compression forces, and torsion can cause displacement, distortion, and / or buckling of structures (e.g., components) of the turbofan engine, such as a bypass duct, a fan case, a compressor case, a shroud, and / or a nacelle, etc. For example, the structures can buckle due to excessive compression forces and / or excessive overturning moments. Certain examples disclosed herein provide a stiffening pattern for a unit cell structure to increase the strength of the unit cell structure and reduce displacement, distortion, and / or buckling of the unit cell structure. Certain examples disclosed herein can be manufactured using additive manufacturing techniques and can induce low aerodynamic disturbances.

[0030] The terms“upstream” and“downstream” refer to the relative direction with respect to the flow of fluid in a fluid path. For example,“upstream” refers to the direction from which fluid flows and“downstream” refers to the direction to which fluid flows. As used herein,“vertical” refers to a direction perpendicular to the ground. As used herein,“horizontal” refers to a direction parallel to the centerline of the gas turbine engine. As used herein,“lateral” refers to a direction perpendicular to the axial direction and the vertical direction (e.g., the plane into and out of the page, etc.). Figure 1

[0031] ​“Comprise” and “contain” (and all forms of these terms) are used herein as open-ended terms. Thus, whenever a claim employs any form of “comprise” or “contain” (e.g., comprises, comprising, contains, containing, etc.) as a transition term, it is open to the full range of equivalents to that transition term. As used herein, the phrase “at least” is used as a transition term in, for example, a preamble of a claim or in any of the claim recitations. It is open-ended in the sense that the transition term precedes a recitation item that has at least one of the recited elements to which the transition term refers. As used herein, the term “and / or” when used in the form “A and / or B” refers to A, B, or the combination of A and B. As used herein in context with describing structures, components, items, objects and / or things, the phrase “at least one of’ A and B” is equivalent to “at least one of A or B.” As used herein in context with describing processes, instructions, acts, activities and / or steps of performing or executing, the phrase “at least one of’ A and B” is equivalent to “at least one of A, B, or a combination of at least one of A and at least one of B.” As used herein in context with describing processes, instructions, acts, activities and / or steps of performing or executing, the phrase “at least one of’ A or B” is equivalent to “at least one of A, B, or a combination of at least one of A and at least one of B.”

[0032] As used herein, singular references (e.g., “a”, “an”, “the”, “first”, “second”, etc.) do not exclude a plurality. As used herein, the term “a” or “an” entity refers to one or more of that entity. The terms “a” (or “an”), “one or more”, and “at least one” can be used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements or method actions can be implemented by, e.g., a single unit or processor. Additionally, although individual features can be included in different examples or claims, these can possibly be combined, and the inclusion of such features is not meant to preclude from the feasibility of the combination and / or claims.

[0033] During flight, gas turbine engines, such as high-bypass and low-bypass turbofan engines, are subjected to operational loads resulting in overturning moments, compressive forces, and torsion. Overturning moments are the fore-to-aft bending moments on the turbofan engine due to the orientation and operation of the aircraft. Axial compressive forces also develop in the turbofan engine due to the orientation and operation of the aircraft during flight. For example, torsion develops in the turbofan engine due to the operation of the internal components of the turbofan engine (e.g., due to the rotation of the compressor and turbine rotors, etc.). The cylindrical or partially cylindrical structural components (e.g., trunks, structures, etc.) of the turbofan engine, such as the bypass duct, fan case, compressor case, shroud, and / or nacelle, are particularly subjected to overturning moments, compressive forces, and / or torsion. The overturning moments, axial compressive forces, and torsion can increase during unbalance events such as fan blade, compressor blade, and turbine blade loss of the fan, compressor, and turbine of the turbofan engine. In addition, the overturning moments, axial compressive forces, and torsion can increase due to inertial loads resulting from hard landings, aircraft maneuvers involving high accelerations (e.g., high g-loads), etc.

[0034] The cylindrical structures (e.g., components) of the turbofan engine, such as the bypass duct, fan case, compressor case, engine shroud, nacelle, exhaust, and / or afterburner, etc., include one or more walled structures (e.g., shells). The overturning moments, compressive forces, and / or torsion induce stresses resulting in compression, out-of-plane deformation, and / or buckling of the walled structures of the cylindrical structures and can result in component failure. To prevent deformation and buckling due to stresses induced by the overturning moments, compressive forces, and / or torsion, the stiffness of the structures needs to be increased. The overturning moments, compressive forces, and / or torsion induce stresses in the cylindrical structures in the circumferential direction, axial direction, and at angles between them. Therefore, it is desirable to increase the stiffness of the cylindrical engine structures in an isotropic manner to prevent deformation and buckling in all directions.

[0035] As used herein, the term "unit cell" refers to a basic structure or "building block" that repeats at regular intervals to form a solid structure. The unit cells are generally of the same size and the same shape, but the size and / or shape of the surface they define can vary. With respect to Figure 9B and Figure 9C The surfaces of unit cells having varying shapes and different shapes are explained in more detail.

[0036] As used herein, the term "lattice" or "array" refers to a solid surface composed of repeating unit cells of a solid. Such two-dimensional lattices or arrays can also be referred to as "crystal lattices," which are defined as solid surfaces, rather than as a collection of nodes or points forming various shapes of voids or openings.

[0037] As used herein, the term“laterally adjacent” refers to sharing a common edge or proximity. For example, squares on a chessboard are laterally adjacent because the black and white squares form a two-dimensional 8x8 grid, with many squares sharing a common edge. Laterally adjacent objects do not have to be in the same vertical plane. Laterally adjacent objects can be connected and offset (e.g., above and below) a neutral plane that defines a centerline through the structure.

[0038] An example surface can be produced from a first plurality or set of cells laterally adjacent and interconnected with a second plurality or set of cells, where cells in the first plurality of cells are offset from a neutral plane in a first radial direction, and cells in the second plurality of cells are offset from the neutral plane in a second radial direction. The interconnected first and second pluralities of cells define a solid surface offset from the neutral plane in an alternating fashion, where the structure is a reinforced structure (e.g., formed from or includes a reinforcement pattern, etc.).

[0039] Some cylindrical structures are formed from a grid of cells at uniform radial locations (e.g., in-line cells) with ribs extending radially outward from the structure at the edges of the cells to increase stiffness (e.g., traditional lattice). However, because the ribs of a cylindrical structure with a traditional lattice are low volume laterally unsupported structures (e.g., radially extending structures), it can be difficult to form the cylindrical structure using additive manufacturing techniques. If a cylindrical structure with a traditional lattice is formed using additive manufacturing techniques, significant post-processing machining is typically required. Furthermore, the ribs of a cylindrical structure including a traditional lattice can extend radially outward from one or more cylindrical faces of the cylindrical structure by 0.5 inches or more, resulting in adverse aerodynamic disruptions.

[0040] The example stiffening patterns (also referred to as stiffened structures or structures with stiffening) disclosed herein increase the stiffness of a lattice structure (e.g., those included in a turbofan engine structure and / or components (e.g., bypass ducts, fan casings, compressor casings, liners, nacelles, and / or engine covers, etc.)) by implementing two opposing surfaces (or subsets of surfaces) of cells connected at nodes (e.g., forming a stiffening pattern). The opposing surfaces of the lattice structures disclosed herein result in an increased moment of inertia relative to a traditional lattice. For example, the increased moment of inertia is determined by calculation due to the geometry of the stiffening pattern. The increased moment of inertia improves the isotropic stiffness of the structure. Example structures are formed with stiffening patterns that include pairs of alternating concave (e.g., inboard relative to a neutral plane or axis) and convex (e.g., outboard relative to a neutral plane or axis) triangular cells that are laterally adjacent to and integral with one another. Alternatively or additionally, example structures are formed with stiffening patterns that include alternating concave (e.g., inboard) and convex (e.g., outboard) triangular cells that are laterally adjacent to and integral with one another that increase in surface dimension. Example structures additionally or alternatively include square cells, rectangular cells, hexagonal cells, etc. For example, the moment of inertia (e.g., the second moment of area) increases due to the local centroid and / or center of cross-sectional area of the alternating concave and convex cells, reducing bending in the panel due to applied forces and / or moments. For example, the location of the cross-sectional centroid, neutral plane, and / or other neutral reference of a structure including the stiffening patterns disclosed herein is between the concave and convex cells, increasing the moment of inertia and strength and reducing bending. For example, the convex cells are offset in a radial or normal direction from the concave cells (about a curved neutral plane). Example structures include different shapes and densities for locally increasing bending stiffness to accommodate concentrated loads (e.g., loads introduced by the inertial loads of accessories mounted on the ducts of an aircraft engine). Structures formed with the stiffening patterns disclosed herein can be easily machined using additive manufacturing techniques (e.g., powder bed fusion (PBF), electron beam melting (EBM), selective laser sintering (SLS), cold spray additive manufacturing (CSAM), superplastic forming, swaging and milling, non-traditional chemical milling, direct metal laser sintering (DMLS), etc.) and / or subtractive manufacturing tools and techniques (e.g., computer numerical control (CNC) milling, electrochemical machining (ECM), etc.). Additionally or alternatively, structures formed with the stiffening patterns disclosed herein can be machined from wrought materials, can be cast, etc. with machining tools and / or chemical machining processes.

[0041] Furthermore, the example reinforcement patterns disclosed herein allow for a lower overall height and / or thickness compared to structures including conventional isogrids with protruding ribs. Thus, the reinforcement patterns disclosed herein can be implemented in conjunction with aircraft components exposed to airflow without generating as much aerodynamic disturbance as conventional isogrids.

[0042] As described above, materials such as cylindrical structures including reinforcement patterns can be used to implement portions of high bypass and / or low bypass gas turbine engines. Referring now to the drawings, in which like numerals represent like elements throughout the figures, Figure 1 1 is a schematic cross-sectional view of an example high-bypass turbofan gas turbine engine 102 ("turbofan engine 102") in which components may be implemented from materials having reinforcement patterns. Turbofan engine 102 is described to provide some example components and illustrate example operating conditions in which such reinforcement structures may be implemented.

[0043] like Figure 1 As shown, the turbofan engine 102 defines a longitudinal or axial centerline axis 104 extending therethrough for reference. The turbofan engine 102 defines a set of axes in a curvilinear coordinate system: a radial axis R, a circumferential axis C, and a longitudinal axis Z. The longitudinal axis Z extends generally parallel to the longitudinal axis 104, and the radial axis R extends outwardly orthogonally from the longitudinal axis 104 (in all directions). The circumferential axis C is measured by an angle Theta (θ) extending around the circumference (radius). As used herein, an angle θ of 0 degrees is a flat surface with a thickness or radius r and a length z, while an angle θ of 360 degrees completes a full cylinder with a thickness or radius r and a length z. A flat surface with an angle θ of 0 degrees can extend parallel to a plane, rather than being curved into a curve with an example angle θ of 10 degrees or a full cylinder with an angle θ of 360 degrees. The turbofan engine 102 includes a core turbine or gas turbine engine 106 disposed downstream of a fan section 108.

[0044] Core turbine engine 106 includes a substantially tubular casing 110 defining an annular inlet 112. Casing 110 may be formed from a single shell or multiple shells. Casing 110 encloses, in serial flow relationship, a compressor section having a supercharger or low-pressure compressor 114 ("LP compressor 114") and a high-pressure compressor 116 ("HP compressor 116"); a combustion section 118; a turbine section having a high-pressure turbine 120 ("HP turbine 120") and a low-pressure turbine 124 ("LP turbine 124"); and an exhaust section 128. A high-pressure shaft or spool 122 ("HP shaft 122") drivingly couples HP turbine 120 and HP compressor 116. A low-pressure shaft or spool 115 ("LP shaft 115") drivingly couples LP turbine 124 and LP compressor 114. LP shaft 115 may also be coupled to a fan spool or shaft 130 of fan section 108. In some examples, LP shaft 115 can be directly coupled to fan shaft 130 (ie, a direct drive configuration). In an alternative configuration, LP shaft 115 is coupled to fan shaft 130 via reduction gear 142 (eg, an indirect drive or gear drive configuration).

[0045] like Figure 1 As shown, fan section 108 includes a plurality of fan blades 136 coupled to and extending radially outward from fan shaft 130. An annular fan casing or nacelle 132 circumferentially surrounds fan section 108 and / or at least a portion of core turbine engine 106. Nacelle 132 may be supported relative to core turbine engine 106 by a plurality of circumferentially spaced outlet guide vanes 134. Furthermore, a downstream section 138 of nacelle 132 surrounds an outer portion of core turbine engine 106 to define a bypass airflow passage 140 therebetween.

[0046] like Figure 1 As shown, during operation of turbofan engine 102, air 148 enters an inlet portion 150 of turbofan engine 102. A first portion 152 of air 148 flows into bypass airflow passage 140, while a second portion 154 of air 148 flows into inlet 112 of LP compressor 114. One or more successive stages of LP compressor stator vanes 117 and LP compressor rotor blades 119 coupled to LP shaft 115 progressively compress the second portion 154 of air 148 flowing through LP compressor 114 and then directing it to HP compressor 116. Next, one or more successive stages of HP compressor stator vanes 121 and HP compressor rotor blades 123 coupled to HP shaft 122 further compress the second portion 154 of air 148 flowing through HP compressor 116. This provides compressed air 156 to combustion section 118, where it is mixed with fuel and combusted to provide combustion gases 125.

[0047] Combustion gases 125 flow through the HP turbine 120, where one or more successive stages of HP turbine stator vanes 127 and HP turbine rotor blades 129 coupled to the HP shaft 122 extract a first portion of kinetic and / or thermal energy from the combustion gases 125. This energy extraction supports operation of the HP compressor 116. The combustion gases 125 then flow through the LP turbine 124, where one or more successive stages of LP turbine stator vanes 131 and LP turbine rotor blades 133 coupled to the LP shaft 115 extract a second portion of thermal and / or kinetic energy from the combustion gases 125. This energy extraction causes the LP shaft 115 to rotate, thereby supporting operation of the LP compressor 114 and / or rotation of the fan shaft 130. The combustion gases 125 then exit the core turbine engine 106 through an exhaust section 128 of the core turbine engine 106.

[0048] As with the turbofan engine 102, the core turbine engine 106 is used for similar purposes and is seen in similar environments in land-based gas turbine engines, turbojet engines, where the ratio of the first portion 152 of air 148 to the second portion 154 of air 148 is less than the ratio of the first portion 152 of air 148 to the second portion 154 of air 148 in turbofan and un-ducted fan engines, where the fan section 108 is free of the nacelle 132. In each of the turbofan, turbojet, and un-ducted engines, a reduction device (e.g., a reduction gear box 142) can be included between any shaft and spool. For example, a reduction gear box 142 can be disposed between the LP shaft 115 and the fan shaft 130 of the fan section 108.

[0049] In Figure 1In the illustrated example, the reinforcement patterns disclosed herein (also referred to as reinforcement structures or reinforced structures) can be implemented in conjunction with structures of the turbofan engine 102 having, for example, cylindrical or annular characteristics. The fan case, bypass duct (e.g., the exterior, interior, or entirety of the bypass duct), and / or the nacelle 132 cowl can include the reinforcement patterns disclosed herein. One or more casings (e.g., compressor casings) of the outer casing 110 can also include the reinforcement patterns disclosed herein. Further, although the reinforcement patterns are discussed in conjunction with the high-bypass turbofan engine 102, the reinforcement patterns disclosed herein can also be implemented in conjunction with low-bypass turbofan engines. For example, a dedicated bypass duct can extend from a fan case at a front of a low-bypass turbofan engine toward a rear of the low-bypass turbofan engine and can include the reinforcement patterns disclosed herein. Further, the exhaust / afterburner section casing, fan case, compressor case, cowl, and / or nacelle of a low-bypass turbofan engine, etc. can also include the reinforcement patterns disclosed herein. The reinforcement patterns can also be used to form liners of turbine engines. The reinforcement patterns formed in the structures provide resistance to buckling, for example, due to compression pressure loading and / or other inward loading.

[0050] More particularly, under compression loading, structures can deform through buckling and / or bending due to differential pressure (ΔΡ). Certain examples provide structures that form surfaces that can help resist such buckling and / or bending effects caused by compression loading (e.g., experienced by a turbine engine in operation, etc.). In some turbine engines, the combustion chamber is a high compression system in which high pressure air and fuel are mixed and burned at constant pressure. The combustion chamber is lined with a combustor or engine liner, which in operation is subjected to high ΔΡ. Certain examples provide reinforcement structures that can be used to form pressure- resistant combustor liners to resist buckling and / or bending effects. Other turbine engine components can be formed from such structures to resist buckling and / or bending due to ΔΡ (e.g., inward) loading and / or other compression pressures, for example.

[0051] FIG. 2 is a perspective view of a known conventional isogrid structure 200 (e.g., conventional isogrid 200, etc.). The known conventional isogrid structure 200 includes conventional cells 202, each of which is defined between three conventional nodes 204 and three conventional ribs 206. Although only a portion of the conventional cells 202, conventional nodes 204, and conventional ribs 206 are labeled in FIG. 2, the unlabeled portions of the known conventional isogrid structure 200 also include the described arrangement of conventional cells 202, conventional nodes 204, and conventional ribs 206. Conventional isogrids (e.g., conventional isogrid structure 200) are load-bearing structures characterized by nodes 204 and / or ribs 206 adhered to a panel, with each pair of nodes, ribs, and panel portions defining a cell 202. As used herein, a “node” abuts two or more cells at a corner of each cell. For example, the cells can be square, rectangular, or triangular, etc. A cylindrical structure formed in the manner of the known conventional isogrid structure 200 includes conventional cells 202 at uniform radial locations (e.g., inline cells), with conventional nodes and ribs 204, 206 extending radially outward and / or inward from the structure at the edges of the conventional cells 202. However, because the conventional nodes and ribs 204, 206 are low-volume, laterally unsupported structures (e.g., radially extending structures), it can be difficult to form a cylindrical structure using additive manufacturing techniques. Where a cylindrical structure is formed using additive manufacturing techniques, significant post-processing machining is often required. Moreover, the conventional ribs 206 of a cylindrical structure including a conventional isogrid can extend radially outward 0.5 inches or more from one or more cylindrical faces of the cylindrical structure, resulting in adverse aerodynamic discontinuities.

[0052] Figure 3A is a perspective view of an example first panel 300 including an example reinforcement pattern for a cell structure that can be implemented in conjunction with the teachings of the present disclosure. In some examples, the reinforcement pattern of the cell structure of the first panel 300 can be implemented in conjunction with at least a portion of a cylindrical structure or a frustoconical structure. In Figure 3A In particular, the first panel 300 includes recessed cells 302 and protruding cells 304 about the nodes 306 (e.g., relative to the conventional cells 202 of the conventional isogrid structure 200 and / or a neutral plane of the first panel 300). In Figure 3AIn particular embodiments, the recessed cells 302 and the protruding cells 304 are equilateral triangles (e.g., triangles). Each recessed cell 302 joins to three protruding cells 304 at respective transition edges 308. Similarly, each protruding cell 304 joins to three recessed cells 302 at respective transition edges 308. Each of the recessed cells 302 and the protruding cells 304 join to three nodes 306 and join to one of the nodes 306 at each corner of the cell, as with the arrangement of the conventional cells 202. Three recessed cells 302 and three protruding cells 304 join to a node 306. Unlike the conventional nodes 204, however, the nodes 306 abut the recessed cells 302 and the protruding cells 304 at opposite ends of the nodes 306. Although only a portion of the recessed cells 302, the protruding cells 304, the nodes 306, and the transition edges 308 are labeled in the examples provided herein, the unlabeled portions of the first panel 300 and other structures implementing the stiffening pattern disclosed herein also include the described arrangement of recessed cells 302, protruding cells 304, transition edges 308, and nodes 306. The recessed cells 302 collectively define a first plurality or set of cells (e.g., a first plurality of triangular cells, etc.). The recessed first plurality of cells 302 is offset from the neutral plane in a first radial direction and is interconnected by the nodes. The protruding cells 304 collectively define a second plurality or set of cells (e.g., a second plurality of triangular cells, etc.). The protruding second plurality of cells 304 is offset from the neutral plane in a second radial direction and is interconnected by the nodes. Although triangular cells are provided as an example, the first and / or second plurality of cells can include rectangular and / or square cells arranged in a waffle grid, cells of different sizes, cells of different shapes, etc.

[0053] In Figure 3A In particular embodiments, the alternating arrangement of the recessed cells 302 and the protruding cells 304 creates opposing surfaces (e.g., surfaces that are displaced from one another) by aligning the recessed cells 302 opposite the protruding cells 304. A first surface is defined by the recessed cells 302, and a second surface is defined by the protruding cells 304. The nodes 306 join the first surface to the second surface (e.g., collectively, the opposing surfaces) by joining the alternating cells of the recessed cells 302 and the protruding cells 304 to one another. The first surface is displaced (e.g., offset) from the second surface in a normal (e.g., 90 degrees, perpendicular, orthogonal) direction on the radial axis R by a distance that increases the moment of inertia of the first panel 300 and increases the resistance of the first panel 300 to bending (e.g., out-of-plane bending or flexing). The cells in the recessed cells 302 alternate with the cells in the protruding cells 304 such that the cells are laterally adjacent, forming a grid arrangement. In Figure 3AIn the example of , the first direction is perpendicular or orthogonal to the first surface. In addition, because each of the recessed cells 302 and the protruding cells 304 is an equilateral triangle (e.g., a triangle), the first panel 300 has increased resistance to bending regardless of the axis about which the panel 300 is bent and / or the panel 300 has isotropic macroscopic properties. In other examples, each of the recessed cells 302 and the protruding cells 304 is a square cell and has orthotropic macroscopic properties (e.g., an orthotropic grid structure), forming a waffle grid. Figure 3A , the node 306 includes an outer edge 310 surrounding a first recess 312. Although only one of the outer edges 310 and one of the first recesses 312 are labeled on one of the nodes 306, each node 306 on the first panel 300 includes an outer edge 310 and a first recess 312. It should be noted that each unit cell need not have isotropic macroscopic properties.

[0054] exist Figure 3A In FIG, a reinforcement pattern created by two offset (eg, protruding and recessed) multiple cells 302, 304 connected by a node strengthens the structure. Figure 4 Further discussed) is planar (e.g., non-cylindrical) because the reinforcement pattern is provided on the first panel 300, which does not include an arched curvature (e.g., an arched curvature associated with a cylindrical and / or annular structure). In other examples, the opposing surfaces (e.g., first and second surfaces) defined by the concave cells 302 and the protruding cells 304 can be annular surfaces, cylindrical surfaces, etc. Figure 7 The cylindrical structure shown is described in more detail Figure 3A FIG. 1 is an example embodiment of a reinforcement pattern of the first panel 300 .

[0055] Figure 3B yes Figure 3A A front view of the first panel 300 is shown showing cut line AA 314 and cut line BB 316. Figure 3B In the view of FIG, the first panel 300 is broken on each side. Therefore, the concave cells 302, protruding cells 304, nodes 306 and transition edges 308 ( Figure 3A part of all) appears in Figure 3B Node 306 is shown with a first contour line 318 to illustrate the first concave portion 312 ( Figure 3A). The first distance 320 indicates the triangular height of the cells of the recessed cell 302 and the protruding cell 304. In some examples, the first distance 320 is 2 inches (or approximately 2 inches ± 0.01 inches, etc.). In some examples, the first distance 320 is between 1 inch and 3 inches.

[0056] Figure 4 It is along Figure 3B The AA cutting line 314 is intercepted Figure 3A An enlarged view of a cross section of the first panel 300 is shown. Figure 4 In the view of , the first panel 300 is broken on each side. Figure 4 The concave cell 302 and the protruding cell 304 appear in the view of Figure 3A Part of both. Figure 4 , the cutting of the AA cutting line 314 is perpendicular to the first distance 320 ( Figure 3B ) is taken from the triangle height of the cells 302, 304 indicated by , and the cuts of the AA cut line 314 are shifted from the edges of alternating cells in the recessed cells 302 and the protruding cells 304 by about half the first distance 320 (eg, the triangle height). Figure 4 , a first dot-dash line 401 indicates a neutral plane for bending (e.g., the location where the in-plane shear stress measured between the second surface 404 and the first surface 402 is zero when subjected to bending about a longitudinal axis Z, wherein the longitudinal axis Z extends perpendicularly into and / or out of the Figure 4 If the example cross section of the first panel 300 is bent completely around the longitudinal axis Z, a cylindrical structure is formed because the direction around the circumferential axis C will rotate completely around the circle (for example, θ is 360), as shown in FIG. Figure 7 However, Figure 4 An example of a non-cylindrical sheet is one in which θ is 0, does not experience any bending, and the cells are laterally adjacent along the longitudinal axis (e.g., front to back) and laterally adjacent side to side (e.g., left to right). The cells 302, 304 are laterally adjacent and therefore share a common edge despite being radially offset in the radial direction R. The neutral plane indicated by the dotted line 401 divides the first panel 300 into a first portion (e.g., including the first portion of each protruding cell 304, in FIG. Figure 4 ) and a second portion (eg, including a second portion of each recessed cell 302, in Figure 4surface or structure of the example panel 300 resulting from the interconnection of the first plurality of cells 302 and the second plurality of cells 304 is a continuous solid surface that alternates between two planes (e.g., a protruding plane and a recessed plane) with a certain offset distance from a neutral plane. Similarly, the neutral plane, indicated by the first dash-dot line 401, intersects each of the nodes 306 and the transition edges 308 of the first panel 300. In some examples, the reinforcement patterns disclosed herein include a curvature. In these examples, the neutral plane is not necessarily perfectly planar (e.g., straight), but rather locally partitions the recessed cells 302 and the protruding cells 304.

[0057] Accordingly, reinforcement patterns can be implemented with respect to a neutral plane to define various structures of various shapes (e.g., curved, flat, angled, etc.). For example, a spiral structure can be formed that includes a reinforcement pattern disclosed herein that includes a corresponding spiral neutral plane extending through the spiral structure that separates recessed cells (e.g., recessed cells 302) from protruding cells (e.g., protruding cells 304). As another example, an exterior of an airfoil (e.g., including a leading edge, a trailing edge, and a chord) can be formed to include a reinforcement pattern disclosed herein that includes a neutral plane having a curvature and shape of the exterior of the airfoil that separates recessed cells (e.g., cells closer to a center of the airfoil) from protruding cells (e.g., cells farther from the center of the airfoil). As yet another example, an ovoid structure can be formed to include a reinforcement pattern disclosed herein that includes an ovoid neutral plane that separates protruding cells from recessed cells.

[0058] In Figure 4 In the orientation of the first plurality or group or set 402 is defined by (e.g., aligned with, in the same plane as) the recessed cells 302. Similarly, the second plurality or group or set 404 is defined by (e.g., aligned with, in the same plane as) the protruding cells 304. A second distance 406 (e.g., an offset in the R direction) that indicates a total thickness of the first panel 300 is defined by (e.g., between a lower face of the recessed cells 302 and an upper face of the protruding cells 304) the first surface 402 and the second surface 404. In some examples, the second distance 406 is 0.3 inches (or approximately 0.3 inches ± 0.01 inches, etc.). In comparison to structures that include traditional equilattice grids, such as the traditional equilattice structure 200 (FIG. 2), the reinforcement patterns disclosed herein allow for a lower total height and / or thickness (e.g., second distance 406).

[0059] The third distance 408 of the first panel 300 is the thickness of the recessed cell 302 and / or the protruding cell 304. In some examples, the third distance 408 is 0.025 inches (or 0.025 inches ± 0.01 inches, etc.). In some examples, the third distance 408 is between 0.025 inches and 0.5 inches. In some examples, the tolerance of the third distance 408 is between ± 0.005 inches and ± 0.01 inches.

[0060] The fourth distance 410 is the thickness of the transition edge 308 of the first panel 300. The fourth distance 410 may be the web thickness of the first panel 300 (e.g., the thickness of a connecting portion such as the transition edge 308). In some examples, the fourth distance 410 is 0.025 inches (or 0.025 inches ± 0.01 inches, etc.). In some examples, the fourth distance 410 is between 0.025 inches and 0.05 inches. In some examples, the tolerance of the fourth distance 410 is between ± 0.005 inches and ± 0.01 inches.

[0061] exist Figure 4 , the lower body 412 of the node 306 is visible. The lower body 412 is positioned at the intersection of the example lower side 414 of the transition edge 308. For example, the lower body 412 is rounded to allow the first concave portion 312 ( Figure 3A ). The bottom portion 412, and more generally, the node 306, includes edge portions of the cells 302, 304 to increase the stiffness of the first panel 300. In some examples, a first portion of the cells 302, 304 has one or more different dimensions than a second portion of the cells 302, 304 (e.g., different values ​​for the first distance 320, the second distance 406, the third distance 408, and / or the fourth distance 410, etc.).

[0062] Figure 5 It is along Figure 3B BB cutting line 316 intercepted Figure 3A Another enlarged cross-section of the first panel 300. Figure 5 In the view of , the first panel 300 is broken on each side. Figure 5 , the cutting of BB cutting line 316 will cut node 306 ( Figure 3A ) is divided into two. Figure 5 , the first panel 300 includes example rounded corners 502 at the junction of the recessed cells 302 and the transition edge 308 and at the junction of the protruding cells 304 and the transition edge 308. For example, the radius of the rounded corners 502 is 0.55 inches (eg, ±0.01 inches, etc.).

[0063] exist Figure 5In the view of FIG, the node 306 is shown as being bisected, revealing a cross section of the first recess 312. Figure 5 In FIG, the underside of the node 306 includes the second recess 504. Including the first recess 312 and the second recess 504 can reduce the material used for the reinforcement pattern of the first panel 300. Figure 5 , the transition edge 308 is relative to the first surface 402 ( Figure 4 ) extends from the recessed cell 302 at a first angle 506. For example, the first angle 506 can be 30° ± 5°. In some examples, the first angle 506 is less than 90° so that the first panel 300 can be formed using an additive manufacturing process.

[0064] exist Figure 5 Visible in the view of FIG306 is an annular thickened portion 508 of node 306. Thickened portion 508 defines first recess 312 and second recess 504 of node 306. Furthermore, thickened portion 508, first recess 312, and second recess 504 of node 306 indicate that node 306 is substantially symmetrical about example third dashed line 510. As used herein, "substantially symmetrical" refers to a situation where the portion of node 306 below third dashed line 510 can be rotated 180°±10° to obtain the shape of the portion of node 306 above third dashed line 510. In some examples, the remainder of first panel 300 exhibits this symmetry.

[0065] Figure 6 yes Figure 3A Another perspective view of the first panel 300 is shown, showing the reverse side of the first panel 300. Figure 6 The view of FIG. 3 shows the underside of the concave cell 302 and further illustrates the symmetry present in the first panel 300. The second concave portion 504 of the node 306 is also Figure 6 shown in the view of . Figure 6 is an example "sheet" or non-cylindrical surface having an angle θ of 0 degrees, which also extends parallel to the neutral plane. Figure 7 Depicts the formation of a cylindrical body by bending the sheet through an angle θ of 360 degrees about the longitudinal axis Z. Figure 6 An example sheet of.

[0066] Figure 7 is a perspective view of an example cylindrical structure 700 that may be implemented to include a Figures 3A-6 Alternatively, the cylindrical structure 700 may be a frusto-conical structure (e.g., a cylinder having an opening of a specific radius at one end and an opening of a different radius at the other end). Figure 7 In combination Figure 1The directional convention of the turbofan engine 102 is discussed with respect to the cylindrical structure 700. For example, the central axis of the cylindrical structure coincides with the longitudinal and centerline axis 104 of the turbofan engine 102. In some examples, the cylindrical structure 700 includes a geometric variation Figures 3A-6 of all aspects of the first panel 300 to illustrate the curvature of the cylindrical structure 700. In some examples, the cylindrical structure is a single structure (e.g., monolithic, unitary, etc.) composed of a continuous material.

[0067] When implemented in conjunction with the cylindrical structure 700, the alternating cells of the recessed cells 302 and the protruding cells 304 form a spiral around the cylindrical structure 700, which is partially indicated by an example fourth dashed line 702 that traces one such spiral. An example fifth dashed line 704 indicates a linear arrangement of the alternating cells of the recessed cells 302 and the protruding cells 304 that is parallel to the centerline axis 104. Along the fourth dashed line 702 and the fifth dashed line 704, the recessed cells 302 can be the inboard cells 302 and the protruding cells 304 can be the outboard cells 304. The inboard cells 302 are disposed closer to the centerline axis 104 of the cylindrical structure 700 than the outboard cells 304.

[0068] In other examples, the alternating recessed cells 302 and the protruding cells 304 can be arranged in a ring (e.g., a portion of the transition edge 308 is arranged along a circumference of the cylindrical structure 700) around a central axis (e.g., the longitudinal axis Z) of the cylindrical structure 700. The cylindrical structure 700 can represent a cylindrical and / or annular structure, such as a fan case, a bypass duct, and / or a cowl of the nacelle 132 Figure 1 ), and / or a component of a low-bypass turbofan engine, etc. Accordingly, the geometry of the component (e.g., the fan case, the bypass duct, and / or the cowl of the nacelle 132, etc.) can include one or more contours, edges, protrusions, cavities, holes, etc. (e.g., geometric features) that are different from the shape of the cylindrical structure 700. The arrangement of the reinforcement pattern shown in conjunction with the cylindrical structure 700 can be modified to account for any of these geometric features.

[0069] In Figure 7 , the opposing surfaces formed by the recessed cells 302 and the protruding cells 304 are cylindrical surfaces. A first cylindrical surface is defined by the recessed cells 302, and a second cylindrical surface is defined by the protruding cells 304, which together form the cylindrical structure 700. Locally, the arrangement of the recessed cells 302 relative to the protruding cells 304 maintains the high moment of inertia and isotropic properties. Accordingly, the arrangement of the cylindrical structure 700 resists bending moments, compressive forces, and torsion. In Figure 7In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304.

[0070] In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304. Figure 7 In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304. Figure 7 In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304.

[0071] In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304. Figure 7 In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304. Figure 7 In particular, the cylindrical structure will always have a varying neutral plane that defines a cylindrical shell that separates each recessed cell 302 from each protruding cell 304. To form the cylindrical structure (e.g., cylindrical structure 700), the recessed cells 302 and / or the protruding cells 304 are bent (e.g., curved) through an angle Θ of 360 degrees to form the curvature of the cylindrical structure 700. Additionally or alternatively, to form the cylindrical structure (e.g., cylindrical structure 700), laterally adjacent cells in the recessed cells 302 and / or the protruding cells 304 are formed at an angle relative to each other. It is important to note that the local arrangement of the recessed cells 302 does not need to be isotropic relative to the protruding cells 304.

[0072] The cylindrical structure 700 includes a first end 706 and a second end 708. The first end 706 includes a first flange 710 extending radially outwardly therefrom, and the second end 708 includes a second flange 712 extending radially outwardly therefrom.

[0073] Cylindrical structure 700 and similar aircraft components (e.g., fan cases, bypass ducts, and / or shrouds, etc.) can be formed using additive manufacturing processes, for example, from first end 706 to second end 708. For example, cylindrical structure 700 and similar aircraft components can be formed using additive manufacturing tools and techniques (e.g., PBF, EBM, CSAM, SLS, DMLS, etc.), and / or subtractive manufacturing tools and techniques (e.g., CNC milling, ECM, etc.) can be used to form cylindrical structure 700.

[0074] Examples disclosed herein provide a structure (e.g., cylindrical structure 700 and / or similar aircraft components) comprising: a first plurality of cells (e.g., recessed cells 302) forming a first surface (e.g., Figure 4 of first surface 402); a second plurality of cells (e.g., protruding cells 304) forming a second surface (e.g., Figure 5 of second surface 404), the first surface and the second surface opposing to produce a high moment of inertia; and a plurality of nodes (e.g., nodes 306) joining the first surface and the second surface to form a reinforcement pattern. The structure can be a cylindrical structure (e.g., cylindrical structure 700) defining a central axis and a radial direction, the second surface (e.g., the second surface defined by protruding cells 304 of cylindrical structure 700) being more radially distant from the central axis than the first surface (e.g., the first surface defined by recessed cells 302 of cylindrical structure 700). The structure (e.g., cylindrical structure 700) can form at least a portion of a duct of a turbofan engine (e.g., turbofan engine 102). At least one cell of the first plurality of cells (e.g., recessed cells 302) or the second plurality of cells (e.g., protruding cells 304) of the structure can be triangular. The structure can include a transition edge (e.g., transition edge 308) further joining the first plurality of cells (e.g., recessed cells 302), the second plurality of cells (e.g., protruding cells 304), and the plurality of nodes (e.g., nodes 306). At least one node of the plurality of nodes (e.g., nodes 306) can include a recess (e.g., first recess 312 and / or second recess 504). The first plurality of cells (e.g., recessed cells 302) can form a first equilattice, and the second plurality of cells (e.g., protruding cells 304) can form a second equilattice.

[0075] Examples disclosed herein provide a cylindrical structure (e.g., a duct of a turbofan engine 102 represented by cylindrical structure 700) around a gas turbine (e.g., a core turbine engine 106) defining a radial direction R and a longitudinal direction Z, the cylindrical structure comprising: a first plurality of cells (e.g., concave cells 302) defining a first portion of a surface (e.g., a first surface defined by concave cells 302 of cylindrical structure 700); a second plurality of cells (e.g., convex cells 304) defining a second portion of the surface (e.g., a first surface defined by convex cells 304 of cylindrical structure 700), the first plurality of cells being in pairwise interconnection with the second plurality of cells, the pair being formed by a cell from the first plurality of cells being radially adjacent to a cell from the second plurality of cells, the cells in the first plurality of cells being radially displaced relative to a central axis (e.g., a longitudinal axis) of the cylindrical structure from the cells in the second plurality of cells to produce a high moment of inertia; and a plurality of nodes (e.g., nodes 306) joining the cells from the first plurality of cells with the cells from the second plurality of cells.

[0076] The cylindrical structure can include a plurality of transition edges (e.g., transition edges 308) to further join the first plurality of cells and the second plurality of cells. The first plurality of cells can be a first plurality of triangular cells, and the second plurality of cells can be a second plurality of triangular cells. A transition edge of the plurality of transition edges can join a first edge of a first cell of the first plurality of cells (e.g., an edge of a concave cell 302), a second edge of a second cell of the second plurality of cells (e.g., an edge of a convex cell 304 adjacent to a concave cell 302), and a node of the plurality of nodes (e.g., a node 306). For example, the cylindrical structure can be associated with an exterior of a duct of a turbofan engine (e.g., turbofan engine 102). The locations of the plurality of nodes can be equidistant. At least one node of the plurality of nodes can include a recess (e.g., a first recess 312 and / or a second recess 504).

[0077] Figure 8A is a perspective enlarged view of an example second panel 800 including a reinforcement pattern for Figures 3A-7 a cell structure of the first panel 300. In Figure 8A , the alternative node 802 is a hybrid node to reduce material usage and increase strength. In Figure 8A , the second panel 800 includes all aspects of the first panel 300 except for the nodes 306 Figure 3A . In Figure 8AOnly a portion of the recessed cells 302, protruding cells 304, alternating nodes 802, and transition edges 308 are labeled, but the unlabeled portion of the second panel 800 also includes the depicted arrangement of recessed cells 302, protruding cells 304, transition edges 308, and alternating nodes 802.

[0078] Figure 8B yes Figure 8A A front view of the second panel 800 is shown, showing the cut line CC 804. Figure 8B As shown, the cutting line CC 804 bisects the alternating node 802 (eg, the mixing node). Figure 8B In the view of FIG, the recessed cells 302 and the protruding cells 304 can be seen.

[0079] Figure 8C It is along Figure 8B Cutting line CC 804 intercepted Figure 8A A cross section of the second panel 800. Figure 8C In the embodiment, the second panel 800 includes a thin thickness (eg, Figure 4 The top and bottom sides of the second panel 800 are at Figure 8C The transition edge 308 near the protruding cell 304 is visible in the view of Figure 8C The transition edge 308 near the recessed cell 302 is visible on the top side of the second panel 800. Figure 8C is visible on the underside of the second panel 800 in the view of FIG. Figure 8C , the second dot-dash line 805 represents a neutral plane (e.g., a neutral reference) of the second panel 800. The neutral plane indicated by the second dot-dash line 805 is located between the recessed cells 302 and the protruding cells 304. The neutral plane indicated by the second dot-dash line 805 divides the first panel 300 into a first portion (e.g., a first portion including each of the protruding cells 304, Figure 8C ) and a second portion (eg, including a second portion of each of the recessed cells 302, in the Figure 8C ). Similarly, the neutral plane indicated by the second dotted line 805 intersects each of the transition edges 308 of the second panel 800. The alternative nodes 802 include Figure 8C The first mixing region 806 (eg, a recess, a well, etc.) on the top side of the second panel 800 is shown in FIG. The alternative node 802 includes Figure 8C A second mixing region 808 (eg, a recess, a well, etc.) on the underside of the second panel 800 is shown in FIG. Figure 8CIn the embodiment, the first mixing region 806 is concave upward and the second mixing region 808 is concave downward. Figure 8C In the example of FIG. 8 , the second mixing region 808 can be viewed as a 180° reflection of the first mixing region 806 around the node transition 810 .

[0080] Figure 9A is included Figures 3A-8C Front view of an example cylindrical structure model 900 of a reinforcement pattern. The cylindrical structure model 900 may be combined with Figure 10 The finite element analysis (FEA) and / or failure mode and effects analysis (FMEA) discussed in more detail are performed. Generally, the cylindrical structure model 900 includes Figure 7 The cylindrical structure 700 has the same features as the cylindrical structure 700, except that the flanges 710, 712 ( Figure 7 ). In addition, the geometry of the cells 302, 304, nodes 306, transition edges 308, and more generally, the cylindrical structure model 900 is not proportional to the cylindrical structure 700. The cylindrical structure model 900 includes a transition edge 308 having a thickness of 0.9 inches (e.g., Figure 4 The cylindrical structure model 900 includes a concave unit cell 302 and a protruding unit cell 304 having a thickness of 0.032 inches (e.g., Figure 4 The cylindrical structure model 900 includes a triangle height of 1.57 inches (e.g., Figure 3B The cylindrical structure model 900 includes a radial height of 0.185 inches (e.g., Figure 4 A compressive load 902 and a moment 904 (eg, an overturning moment) may be applied to the cylindrical structural model 900, which is constrained by the fixed support 906. Figures 9A-10 In the illustrated example, compressive loads 902 and moments 904 simulate induced loads and moments in the bypass duct of a low-bypass and / or high-bypass turbofan engine.

[0081] Figure 9B is included Figures 3A-8C A front view of an example cylindrical structure model 920 of a reinforcement pattern. The cylindrical structure model 920 is similar to Figure 9AExample cylindrical structure 900, but with cells of varying sizes rather than uniform size. Furthermore, the geometry of cells 932, 934, nodes 936, transition edges 938, and more generally, cylindrical structure model 920 is not proportional to example cylindrical structure 900. Cells 932 and 934 are both cells, although cell 934 is a larger triangular shape than cell 932. This variation in cell size is useful, for example, for creating structures of different sizes at different ends.

[0082] Figure 9C is included Figures 3A-8C 9 . A front view of an example cylindrical structure model 940 of a reinforcement pattern, wherein the shape of the cells varies. Generally, the cylindrical structure model 940 includes the same features as the cylindrical structure 900 of FIG. 9 , but the cell shapes are different. In addition, the geometry of the cells 942, 944, the nodes 946, the transition edges 948, and more generally, the cylindrical structure model 940 is not proportional to the example cylindrical structure 900. Cell 942 is a small triangular cell, while cell 944 is a larger quadrilateral cell. The example structure model 940 illustrates that cells 942, 944 do not have to have the same shape to create a surface. For example, transitions can occur between multiple different cells. For example, cell 944 can be a hexagonal cell that transitions to a pentagonal cell. For example, such variations in cell shape can be used to create structures with transitions.

[0083] Figure 10 It is a traditional equal grid structure and includes Figure 3A Graph 1000 of the buckling coefficient of a structure (e.g., cylindrical structural model 900) having a reinforcement pattern of -9. Buckling coefficient 1002 represents the safety factor of a material against buckling at a critical load, or the ratio of the structure's capacity to the structure's design requirements. A higher buckling coefficient 1002 indicates a lower buckling tendency of the structure. In a nonlinear FEA buckling coefficient analysis, when a critical load is gradually applied in discrete loading steps, the lowest buckling coefficient relative to the applied critical load is determined. In the experimental FEA results shown in graph 1000, a first buckling coefficient 1006 determined in the nonlinear buckling coefficient analysis is shown for the cylindrical structural model 900 implementing the reinforcement pattern disclosed herein. In the experimental FEA results shown in graph 1000, a second buckling coefficient 1010 determined in the nonlinear buckling coefficient analysis is shown for a structure including a conventional isogrid (not shown).

[0084] exist Figure 10In this example, the first buckling coefficient 1006 is approximately 1.4 and the second buckling coefficient 1010 is approximately 1.4. The first buckling coefficient 1006 determined for the cylindrical structural model 900 including the reinforcement pattern disclosed herein satisfies the second buckling coefficient 1010 of a conventional equivalent grid structure while having increased manufacturability and reduced material usage.

[0085] Figure 11 represents an assembled aircraft component and / or engine component (e.g., a structure) including a reinforcement pattern for a unit cell structure of -9. Figure 3A An example method 1100 for manufacturing an aircraft component and / or engine component (e.g., a bypass duct, a fan case, a compressor case, a shroud, a nacelle, etc.) including a reinforcement pattern for a unit cell structure of -9 is shown in a flowchart. The method 1100 begins by selecting parameters for an additive manufacturing process to form the component. (Block 1110). For example, materials, nozzle geometry, nozzle tool path and surface speed, gas composition, pressure and temperature, number of passes to achieve a desired thickness, etc. One or more process simulations can be completed to ensure proper part coverage and thickness, and / or to optimize or otherwise improve the process parameter selection for the component.

[0086] The method 1100 continues by creating executable instructions for an additive manufacturing tool to form the aircraft component and / or engine component including the reinforcement pattern. (Block 1120). For example, the instructions are created based on a 3D part file for the component and / or a 3D mesh for the component (e.g., a stereolithography file (.stl), etc.) and the selected parameters. The instructions can include one or more tool movement patterns, deposition speeds, etc., to form the aircraft component and / or engine component. The materials to be used to form the component are prepared (e.g., feedstock, process gases, a platform, a substrate, and / or an environment, etc.). (Block 1130). The method 1100 continues by forming the component from the tool according to the provided instructions. (Block 1140).

[0087] Any post-processing machining (e.g., subtractive manufacturing, milling operations, etc.) is completed on the aircraft component and / or engine component to achieve, for example, increased tolerances and fine features of the component. (Block 1150). In some examples, no post-processing machining is completed. After block 1150, the method 1100 ends with the production and output of the aircraft component and / or engine component.

[0088] Figure 11 A flowchart representing example hardware logic, machine readable instructions, hardware-implemented state machines, and / or any combination thereof is shown in FIG. 10. The machine readable instructions can be one or more executable programs or portions of executable programs for execution by a computer processor (e.g., the processor 1020 described below in connection with FIG. 10). Figure 12The computer processor is used to drive the additive manufacturing equipment to perform the process 1100 to manufacture one or more aircraft parts and / or engine parts. The program may be embodied in software stored on a non-transitory computer-readable storage medium (such as a CD-ROM, floppy disk, hard drive, DVD, Blu-ray disk, or memory associated with the processor 1212), but the entire program and / or parts thereof may alternatively be executed by a device other than the processor 1212 and / or embodied in firmware or dedicated hardware. In addition, although reference is made to Figure 11 The flowchart shown describes an example procedure, but an example manufacturing process is implemented to form a Figures 3A-7 Many other methods of implementing a reinforcement pattern of a cell structure for an example aircraft component (e.g., a structure) may also be used. For example, the order of execution of the blocks may be changed, and / or some of the blocks described may be changed, eliminated, or combined. Additionally or alternatively, any or all of the blocks may be implemented by one or more hardware circuits (e.g., discrete and / or integrated analog and / or digital circuits, FPGAs, ASICs, comparators, operational amplifiers (op-amps), logic circuits, etc.) configured to perform the corresponding operations without executing software or firmware.

[0089] As mentioned above, Figure 11 The example processes of can be implemented using executable instructions (e.g., computer and / or machine readable instructions) stored on a non-transitory computer and / or machine readable medium (e.g., a hard drive, flash memory, read-only memory, compact disc, digital versatile disk, cache, random access memory, and / or any other storage device or storage disk in which information is stored for any duration (e.g., for an extended period of time, permanently, transiently, temporarily buffered, and / or cached information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage device and / or storage disk and does not include propagating signals and does not include transmission media.

[0090] Figure 12 is a block diagram of an example processor platform 1200 configured to perform Figure 11 to drive and / or otherwise control an additive manufacturing device (e.g., PBF, EBM, CSAM, SLS, DMLS, or tool, etc.) to perform an example manufacturing process to form a material including a Figures 3A-7 The processor platform 1200 may be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a cell phone, a smartphone, an iPad, etc.) TMa tablet computer, etc.), a personal digital assistant (PDA), an Internet appliance, a DVD player, a CD player, a digital video recorder, a Blu-ray player, a game console, a personal video recorder, a set-top box, a headset or other wearable device, or any other type of computing device.

[0091] The processor platform 1200 of the illustrated example includes a processor 1212. The processor 1212 of the illustrated example is hardware. For example, the processor 1212 can be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor can be a semiconductor based (e.g., silicon based) device. In this example, the processor 1212 implements the methods 1100, among other things. Figure 11 a controller of an additive manufacturing process.

[0092] The processor 1212 of the illustrated example includes a local memory 1213 (e.g., a cache). The processor 1212 of the illustrated example, via bus 1218, is in communication with a main memory including volatile memory 1214 and non-volatile memory 1216. Volatile memory 1214 can be implemented by synchronous dynamic random access memory (SDRAM), dynamic random access memory (DRAM), RAMBUS dynamic random access memory (RAMBUS DRAM), and / or any other type of random access memory device. Non-volatile memory 1216 can be implemented by flash memory and / or any other desired type of memory device. Access to volatile and non-volatile memory 1214, 1216 is controlled by a memory controller. dynamic random access memory and / or any other type of random access memory device. Non-volatile memory 1216 can be implemented by flash memory and / or any other desired type of memory device. Access to volatile and non-volatile memory 1214, 1216 is controlled by a memory controller.

[0093] The processor platform 1200 of the illustrated example also includes an interface circuit 1220. The interface circuit 1220 can be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), a Bluetooth interface, a near field communication (NFC) interface, and / or a PCI express interface.

[0094] In the illustrated example, one or more input devices 1222 are connected to the interface circuit 1220. The input device(s) 1222 permit a user to enter data and / or commands into the processor 1212. The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a trackpad, a trackball, isopoint, and / or a voice recognition system.

[0095] One or more output devices 1224 are also connected to the interface circuit 1220 of the illustrated example. The output devices 1224 can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube display (CRT), an in-place switching (IPS) display, a touchscreen, etc.), a tactile output device, a printer and / or speakers. In this regard, the interface circuit 1220 of the illustrated example, in

[0096] The interface circuit 1220 of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem, a residential gateway, a wireless access point, and / or a network interface to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network 1226. The communication can be via, for example, an Ethernet connection, a digital subscriber line (DSL), a telephone line, a coaxial cable, a satellite system, a

[0097] The processor platform 1200 of the illustrated example also includes one or more mass storage devices 1228 for storing software and / or data. Examples of such mass storage devices 1228 include floppy

[0098] Figure 11 Machine executable instructions 1232 of the example of FIG. 12 can be stored in the mass storage device 1228, in the volatile memory 1214, in the non-volatile memory 1216, and / or on a removable non-transitory computer readable storage medium such as a CD or DVD.

[0099] From the foregoing, it will be appreciated that example methods, apparatus and articles of manufacture have been disclosed for a reinforcement pattern for a unit cell structure including opposing unit cells joined at nodes. The disclosed examples have increased aerodynamic properties compared to traditional equilattice structures and can be formed using an additive manufacturing process such as PBF, EBM, CSAM, SLS, DMLS or a tool such as a laser, electron beam, etc.

[0100] Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture falling within the scope of the claims.

[0101] Further aspects of the application are provided by the subject matter of the following clauses:

[0102] 1. A structure of an engine component comprising: a first plurality of cells offset from a neutral plane in a first direction; a second plurality of cells offset from the neutral plane in a second direction; and a plurality of nodes joining cells of the first plurality of cells and cells of the second plurality of cells, wherein the first plurality of cells and the second plurality of cells are arranged in pairs such that cells of the first plurality of cells are laterally adjacent to and interconnected with cells of the second plurality of cells, and wherein the structure is a stiffened structure.

[0103] 2. The structure of any of the preceding clauses, wherein the first plurality of cells are aligned in a first protruding plane and the second plurality of cells are aligned in a second recessed plane such that interconnected, laterally adjacent pairs of cells from the first plurality of cells and from the second plurality of cells define a solid stiffened structure that alternates between the first protruding plane and the second recessed plane.

[0104] 3. The structure of any of the preceding clauses, wherein the first surface and the second surface are offset from each other in a normal direction of the first surface and the second surface, and a plurality of nodes join the first plurality of cells and the second plurality of cells to form a stiffened pattern.

[0105] 4. The structure of any of the preceding clauses, wherein the structure forms at least a portion of a cylindrical or frustoconical structure, the first direction is a centerline axis, the second direction is a circumferential direction, the third direction is a radial direction, and the second surface is more radially distant from the centerline axis than the first surface.

[0106] 5. The structure of any of the preceding clauses, wherein the structure comprises a panel and the third direction extends normal to an equivalent neutral bending plane of the panel.

[0107] 6. The structure of any of the preceding clauses, wherein the cylindrical structure forms at least a portion of a duct of a turbofan engine.

[0108] 7. The structure of any of the preceding clauses, wherein at least one cell of the first plurality of cells or the second plurality of cells is triangular.

[0109] 8. The structure of any of the preceding clauses, further comprising a plurality of transition edges further joining the first plurality of cells, the second plurality of cells, and the plurality of nodes.

[0110] 9. The structure of any of the preceding clauses, wherein at least one cell of the first plurality of cells or the second plurality of cells is a different size than at least one other cell of the first plurality of cells or the second plurality of cells.

[0111] 10. The structure of any of the preceding clauses, wherein at least one cell of the first plurality of cells or the second plurality of cells is a different geometry than at least one other cell of the first plurality of cells or the second plurality of cells.

[0112] 11. The structure of any of the preceding clauses, wherein at least one node of the plurality of nodes is a hybrid node.

[0113] 12. The structure of any of the preceding clauses, wherein the first plurality of cells forms a first equi-grid and the second plurality of cells forms a second equi-grid.

[0114] 13. A structural apparatus surrounding a gas turbine, the structure comprising: a first cell grid defining a first surface; a second cell grid defining a second surface, the first surface offset in a first direction from the second surface to increase a moment of inertia of the structure, cells of the first cell grid alternating with cells of the second cell grid such that the cells are laterally adjacent, and wherein the first direction is perpendicular to the first cell grid and the second cell grid; and a plurality of nodes joining the first cell grid with the second cell grid.

[0115] 14. A structure surrounding a gas turbine, the structure comprising: a first plurality of cells; a second plurality of cells, the first plurality of cells offset in a first direction from the second plurality of cells to increase a moment of inertia of the structure, cells of the first plurality of cells alternating with cells of the second plurality of cells such that the cells are laterally adjacent, and the first plurality of cells and the second plurality of cells offset from one another relative to a neutral plane defining a centerline through the structure; and a plurality of nodes joining the first plurality of cells with the second plurality of cells.

[0116] 15. The structure of any of the preceding clauses, further comprising a plurality of transition edges to further join the first cell grid and the second cell grid.

[0117] 16. The structure of any of the preceding clauses, wherein the first cell grid is a first triangular cell grid and the second cell grid is a second triangular cell grid.

[0118] 17. The structure of any of the preceding clauses, wherein the first cell grid is a first triangular cell grid of different size and the second cell grid is a second triangular cell grid of different size.

[0119] 18. The structure of any of the preceding clauses, wherein the first cell grid is a first grid comprising triangular cells and rectangular cells and the second cell grid is a second grid comprising triangular cells and hexagonal cells.

[0120] 19. The structure of any of the preceding clauses, wherein a transition edge of the transition edges joins a first edge of a first cell of the first cell grid, a second edge of a second cell of the second cell grid, and a node of the plurality of nodes.

[0121] 20. The structure of any of the preceding clauses, wherein the structure is cylindrical and is associated with an exterior of a duct of a turbofan engine.

[0122] 21. The structure of any of the preceding clauses, wherein positions of the plurality of nodes are equidistant.

[0123] 22. The structure of any of the preceding clauses, wherein the circumferential structure is a unitary structure.

[0124] 23. A cell structure of an aircraft component, comprising: a first plurality of cells; a second plurality of cells offset from the first plurality of cells in a first direction, the first plurality of cells and the second plurality of cells forming an opposing surface, cells of the first plurality of cells alternating with cells of the second plurality of cells such that the cells are laterally adjacent and the first direction is orthogonal to the first plurality of cells and the second plurality of cells; and a plurality of nodes joining the first plurality of cells and the second plurality of cells to form a reinforcement pattern.

[0125] 24. A unit cell structure of an aircraft component, comprising: a first plurality of unit cells; a second plurality of unit cells offset from the first plurality of unit cells in a first direction, the first plurality of unit cells and the second plurality of unit cells forming opposing surfaces, unit cells in the first plurality of unit cells alternating with unit cells in the second plurality of unit cells such that the unit cells are laterally adjacent, the first surface and the second surface offset from one another with respect to a neutral plane defining a centerline through the unit cell structure; and a plurality of nodes joining the first plurality of unit cells and the second plurality of unit cells to reinforce the unit cell structure.

[0126] 25. A unit cell structure of an aircraft component, comprising: a first plurality of unit cells; a second plurality of unit cells offset from the first plurality of unit cells in a first direction, the first plurality of unit cells and the second plurality of unit cells forming opposing surfaces, unit cells in the first plurality of unit cells alternating with unit cells in the second plurality of unit cells such that the unit cells are laterally adjacent, and the first direction is orthogonal to the first surface and the second surface; and a plurality of nodes joining the first plurality of unit cells and the second plurality of unit cells to form a reinforcement pattern.

[0127] 26. The structure of any of the preceding clauses, wherein a first unit cell in the first plurality of unit cells is a first triangular unit cell, and a second unit cell in the second plurality of unit cells is a second triangular unit cell.

[0128] 27. The structure of any of the preceding clauses, wherein a first unit cell in the first plurality of unit cells is a first triangular unit cell, and a second unit cell in the second plurality of unit cells is a second triangular unit cell of a different size.

[0129] 28. The apparatus of any of the preceding clauses, wherein a first unit cell in the first plurality of unit cells is a first triangular unit cell, and a second unit cell in the second plurality of unit cells is a first hexagonal unit cell.

[0130] 29. The structure of any of the preceding clauses, wherein the first triangular unit cell is connected at a first edge to a transition edge, the transition edge connected to a second edge of the second unit cell.

[0131] 30. The structure of any of the preceding clauses, wherein the first plurality of unit cells defines a first surface, and the second plurality of unit cells defines a second surface.

[0132] 31. The unit cell structure of any of the preceding clauses, wherein the first plurality of unit cells is in a first protruding plane and the second plurality of unit cells is in a second recessed plane.

[0133] 32. The unit cell structure of any of the preceding clauses, wherein the first surface is offset from the second surface by less than 0.3 inches.

[0134] 33. The unit cell structure of any of the preceding clauses, wherein the first plurality of unit cells is offset from the second plurality of unit cells by less than 0.3 inches.

[0135] 34. The unit cell structure of any of the preceding clauses, wherein the first plurality of unit cells in the first protruding plane is offset from the second plurality of unit cells in the recessed plane by less than 0.3 inches.

[0136] 35. The structure of any of the preceding clauses, wherein a first portion of the first plurality of unit cells has one or more different dimensions than a second portion of the first plurality of unit cells.

[0137] 36. A unitarily additively manufactured integral lattice structure, comprising: a first plurality of triangular unit cells disposed on a first side of a neutral plane for bending the lattice structure; a second plurality of triangular unit cells disposed on a second side of the neutral plane, the second side opposite the first side; a plurality of nodes; and a plurality of transition edges, the plurality of nodes and the plurality of transition edges connecting the first plurality of unit cells and the second plurality of unit cells.

[0138] 37. The apparatus of any of the preceding clauses, wherein at least a portion of the lattice structure comprises a curvature.

[0139] 38. An integrally additively manufactured lattice structure, comprising: a first grid of square unit cells defining a first surface, the first grid of square unit cells disposed on a first side of a neutral plane for bending the lattice structure; a second grid of square unit cells defining a second surface, the second grid of square unit cells disposed on a second side of the neutral plane opposite the first side, the second grid of square unit cells joined to the first grid of square unit cells by a plurality of (a) nodes intersecting the neutral plane and (b) transition edges intersecting the neutral plane.

[0140] 39. A unitized structure having a unit cell, comprising a first portion of the unit cell, a second portion of the unit cell disposed opposite the first portion of the unit cell about a neutral plane, and a plurality of (a) nodes and (b) transition edges joining the unit cell.

[0141] 40. An additively manufactured unitized structure, comprising: a first lattice of unit cells, the first lattice of unit cells opposite a second lattice of unit cells; a neutral plane disposed between the first lattice of unit cells and the second lattice of unit cells; a plurality of nodes; and a plurality of transition edges coupling the first lattice of unit cells and the second lattice of unit cells, the neutral plane extending through at least a portion of the plurality of (a) nodes and (b) unit cells.

[0142] 41. An additively manufactured lattice structure, comprising: a first plurality of square unit cells aligned in a first plane, the first plurality of square unit cells disposed on a first side of a neutral plane for bending the lattice structure; a second plurality of square unit cells aligned in a second plane, the second plurality of square unit cells disposed on a second side of the neutral plane opposite the first side, the second plurality of square unit cells joined to the first plurality of square unit cells by a plurality of (a) nodes intersecting the neutral plane and (b) transition edges intersecting the neutral plane.

[0143] 42. An additively manufactured lattice structure, comprising: a first plurality of square unit cells disposed on a first side of a neutral plane for bending the lattice structure; a second plurality of square unit cells disposed on a second side of the neutral plane opposite the first side, the second plurality of square unit cells joined to the first plurality of square unit cells by a plurality of (a) nodes intersecting the neutral plane and (b) transition edges intersecting the neutral plane.

[0144] The following claims are hereby incorporated by reference into this detailed description, each claim standing on its own as a separate embodiment of the present disclosure.

Claims

1. A structure of an engine component, characterized by, comprising: a first plurality of cells offset from a neutral plane in a first direction, wherein the neutral plane defines a centerline through the structure; a second plurality of cells offset from the neutral plane and the first plurality of cells in a second direction; and a plurality of nodes joining cells of the first plurality of cells and cells of the second plurality of cells, wherein the plurality of nodes includes an outer edge and a recess within the outer edge, wherein the first plurality of cells and the second plurality of cells are arranged in pairs such that a cell of the first plurality of cells is laterally adjacent to and interconnected with a cell of the second plurality of cells, and wherein the structure is a reinforcing structure.

2. The structure of claim 1, wherein wherein the structure forms at least a portion of a cylindrical or frustoconical structure, the first direction is a centerline axis, the second direction is a circumferential direction, and a second surface defined by the second plurality of cells is more radially distant from the centerline axis than a first surface defined by the first plurality of cells.

3. The structure of claim 1, wherein wherein the structure includes a panel and a third direction extends perpendicular to an equivalent neutral bending plane of the panel, and the third direction is a radial direction.

4. The structure of claim 2, wherein wherein the cylindrical structure forms at least a portion of a duct of a turbofan engine.

5. The structure of claim 1, wherein wherein at least one cell of the first plurality of cells or the second plurality of cells is triangular.

6. The structure of claim 1, wherein further comprising a plurality of transition edges further joining the first plurality of cells, the second plurality of cells, and the plurality of nodes.

7. The structure of claim 1, wherein wherein at least one node of the plurality of nodes is a hybrid node capable of reducing material usage and increasing strength.

8. The structure of claim 1, wherein wherein the first plurality of cells forms a first equi-grid defined by nodes and ribs, and the second plurality of cells forms a second equi-grid defined by nodes and ribs.

9. A structure surrounding a gas turbine, characterized by, comprising: a first plurality of cells; a second plurality of cells offset from the first plurality of cells relative to a neutral plane to increase a moment of inertia of the structure, cells of the first plurality of cells alternating with cells of the second plurality of cells to define the structure such that the cells are laterally adjacent, and the first plurality of cells and the second plurality of cells are offset from one another relative to the neutral plane defining a centerline through the structure; and a plurality of nodes joining the first plurality of cells with the second plurality of cells, wherein the plurality of nodes includes an outer edge and a recess within the outer edge.

10. The structure of claim 9, wherein further comprising a plurality of transition edges to further join cells of the first plurality of cells with cells of the second plurality of cells such that the cells of the first plurality of cells are laterally adjacent to the cells of the second plurality of cells.

11. The structure of claim 10, wherein wherein the first plurality of cells is a first plurality of triangular cells, and the second plurality of cells is a second plurality of triangular cells.

12. The structure of claim 11, wherein wherein a transition edge of the transition edges joins a first edge of a first cell of the first plurality of cells, a second edge of a second cell of the second plurality of cells, and a node of the plurality of nodes.

13. The structure of claim 9, wherein wherein the structure is cylindrical and is associated with an exterior of a duct of a turbofan engine.

14. The structure of claim 9, wherein wherein the locations of the plurality of nodes are equidistant.

15. The structure of claim 13, wherein wherein the cylindrical structure is a unitary structure composed of a continuous material.

16. A unit cell structure of an aircraft component, characterized by, comprising: a first plurality of cells; a second plurality of cells offset from the first plurality of cells in a first direction, the first plurality of cells and the second plurality of cells forming opposing surfaces, cells of the first plurality of cells alternating with cells of the second plurality of cells such that the cells are laterally adjacent, a first surface and a second surface offset from one another relative to a neutral plane defining a centerline through the cell structure; and a plurality of nodes joining the first plurality of cells and the second plurality of cells to reinforce the cell structure, wherein the plurality of nodes comprises an outer edge and a recess within the outer edge.

17. The unit cell structure of claim 16, wherein, wherein a first cell of the first plurality of cells is a first triangular cell and a second cell of the second plurality of cells is a second triangular cell.

18. The unit cell structure of claim 17, wherein, wherein the first triangular cell is connected at a first edge to a transition edge, the transition edge connected to a second edge of the second cell.

19. The unit cell structure of claim 16, wherein, wherein the first plurality of cells extends in a protruding plane and the second plurality of cells extends in a recessed plane.

20. The unit cell structure of claim 19, wherein, wherein the first plurality of cells is offset from the second plurality of cells by less than 0.3 inches.

21. The unit cell structure of claim 16, wherein, wherein a first portion of the first plurality of cells has one or more different dimensions than a second portion of the first plurality of cells.

22. An additively manufactured unitized grid structure, characterized by, comprising: a first plurality of triangular cells disposed on a first side of a curved neutral plane for the equi-grid structure, wherein the neutral plane defines a centerline through the equi-grid structure; a second plurality of triangular cells disposed on a second side of the neutral plane, the second side opposite the first side; a plurality of nodes; and a plurality of transition edges, the plurality of nodes and the plurality of transition edges connecting the first plurality of triangular cells and the second plurality of triangular cells, wherein the plurality of nodes comprises the transition edges and a recess within the transition edges.

23. The additively manufactured unitized truss structure of claim 22, wherein, wherein at least a portion of the equi-grid structure comprises a curvature.

24. A unitary additively manufactured lattice structure, characterized by, comprising: a first plurality of square cells defining a first surface, the first plurality of square cells disposed on a first side of a curved neutral plane for the grid structure, wherein the neutral plane defines a centerline through the grid structure; and a second plurality of square cells disposed on a second side of the neutral plane, the second side opposite the first side. a second plurality of square cells defining a second surface, the second plurality of square cells disposed on a second side of the neutral plane opposite the first side, the second plurality of square cells joined to the first plurality of square cells by a plurality of (a) nodes that intersect the neutral plane and (b) transition edges that intersect the neutral plane, wherein the nodes include an outer edge and a recess within the outer edge.

Images