System for spacing and fastening tubular structures

Abstract

A system for spacing and securing tubular structures and related methods. The system includes a spacer element configured to engage a plurality of tubular structures to spatially separate the plurality of tubular structures from one another and distribute stress among the plurality of tubular structures. The system includes a securing element configured to extend around at least a portion of an outer surface of the plurality of tubular structures and secure the plurality of tubular structures to the spacer element in a conformally spaced configuration.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a spacing and fastening system for tubular structures deployed in an engineered assembly. In particular, the present disclosure relates to a spacer element for supporting and separating tubular structures deployed in an engineered assembly. BACKGROUND

[0002] Gas turbine engines and other engineered assemblies typically include an array or set of tubes or pipes deployed in several locations for conveying liquid and gaseous products. The tubes or pipes are typically bundled using spacer elements of permanent linkage such as brazing or welding of blocks and tabs. SUMMARY

[0003] Technical Solution 1. A system comprising:

[0004] a spacer element configured to engage a plurality of tubular structures to spatially separate the plurality of tubular structures from one another and distribute stress among the plurality of tubular structures; and

[0005] a fastening element configured to extend around at least a portion of an outer surface of the plurality of tubular structures and fasten the plurality of tubular structures to the spacer element in an adaptive spaced configuration.

[0006] Technical Solution 2. The system of any preceding technical solution, wherein the adaptive spaced configuration includes a first length of the fastening element below a predetermined temperature range and a second length of the fastening element above the predetermined temperature range, the first length being different than the second length.

[0007] Technical Solution 3. The system of any preceding technical solution, wherein the adaptive spaced configuration includes a first configuration in which the plurality of tubular structures are movably spaced around the spacer element and a second configuration in which the plurality of tubular structures are immovably spaced around the spacer element.

[0008] Technical Solution 4. The system of any preceding technical solution, wherein the fastening element includes a shape memory alloy (SMA) tape, the shape memory alloy (SMA) tape including a nickel-titanium shape memory alloy.

[0009] Technical Solution 5. The system of any preceding technical solution, wherein the spacer element includes:

[0010] (a) a core portion positioned at a center of the spacer element; and

[0011] (b) a plurality of radial arms arranged in a predetermined configuration, each radial arm being joined with the core portion at a respective base, the predetermined configuration comprising a cruciform configuration, or a star configuration, or any combination thereof,

[0012] wherein at least one pair of adjacent radial arms and the core portion form a cradle bracket, the cradle bracket being configured to engage a corresponding tubular structure in the cradle bracket.

[0013] Technical solution 6. The system of any preceding technical solution, wherein the spacer element comprises:

[0014] (a) a first thin-walled bracket for engaging a first tubular structure of the plurality of tubular structures; and

[0015] (b) a second thin-walled bracket for engaging a second tubular structure of the plurality of tubular structures,

[0016] wherein the first thin-walled bracket and the second thin-walled bracket are joined at a top end of the spacer element and at a bottom end of the spacer element.

[0017] Technical solution 7. The system of any preceding technical solution, wherein the spacer element comprises:

[0018] (a) a first cradle bracket configured to engage a first tubular structure of the plurality of tubular structures;

[0019] (b) a second cradle bracket configured to engage a second tubular structure of the plurality of tubular structures; and

[0020] (c) a core portion separating the first cradle bracket and the second cradle bracket,

[0021] wherein the first cradle bracket, the second cradle bracket, and the core portion are joined at a top end of the spacer element and at a bottom end of the spacer element.

[0022] Technical solution 8. The system of any preceding technical solution, wherein a first joint between the first cradle bracket and the top end, or a second joint between the second cradle bracket and the top end, or a third joint between the first cradle bracket and the bottom end, or a fourth joint between the second cradle bracket and the bottom end, or any combination thereof, comprises a fillet joint.

[0023] Technical solution 9. The system of any preceding technical solution, further comprising:

[0024] a first recess formed between the first bracket bracket portion and a first corresponding surface of the core portion, the first recess configured to accommodate a first portion of the fastening element; and

[0025] a second recess formed between the second bracket bracket portion and a second corresponding surface of the core portion, the second recess configured to accommodate a second portion of the fastening element.

[0026] Technical Solution 10. The system of any preceding technical solution, wherein a first tubular structure of the plurality of tubular structures is engaged with the first bracket bracket portion at a first contact surface, and a second tubular structure of the plurality of tubular structures is engaged with the second bracket bracket portion at a second contact surface, the first contact surface or the second contact surface, or both the first contact surface and the second contact surface, include a plurality of surface features configured to distribute stress in the plurality of tubular structures, and the plurality of surface features include a plurality of protrusions, or dimples, or any combination thereof.

[0027] Technical Solution 11. A method comprising:

[0028] providing a spacer element;

[0029] engaging a plurality of tubular structures to the spacer element, spatially separating the plurality of tubular structures from one another, and distributing stress in the plurality of tubular structures;

[0030] extending a fastening element around at least a portion of an outer surface of the plurality of tubular structures; and

[0031] fastening the plurality of tubular structures to the spacer element in an adaptively spaced configuration.

[0032] Technical Solution 12. The method of any preceding technical solution, wherein the fastening of the plurality of tubular structures to the spacer element in the adaptively spaced configuration comprises: fastening the plurality of tubular structures to the spacer element by a first length of the fastening element below a predetermined temperature range; and fastening the plurality of tubular structures to the spacer element by a second length of the fastening element above the predetermined temperature range, the first length being different than the second length.

[0033] Technical Solution 13. The method of any preceding technical solution, wherein the fastening of the plurality of tubular structures to the spacer element in the adaptively spaced configuration comprises fastening the plurality of tubular structures to the spacer element in a first configuration in which the plurality of tubular structures are movably spaced about the spacer element, and a second configuration in which the plurality of tubular structures are immovably spaced about the spacer element.

[0034] TECHNICAL SOLUTION 14. The method of any preceding technical solution, wherein extending the fastening element comprises extending a shape memory alloy (SMA) tape, the shape memory alloy (SMA) tape comprising a nickel-titanium shape memory alloy.

[0035] TECHNICAL SOLUTION 15. The method of any preceding technical solution, wherein the providing of the spacer element comprises: arranging a plurality of radial arms in a predetermined configuration; joining each radial arm at a respective base portion to a core portion of the spacer element; forming a cradle bracket portion having at least one pair of adjacent radial arms and the core portion; and joining a corresponding one of the plurality of tubular structures in the cradle bracket portion, and the arranging of the plurality of radial arms in the predetermined configuration comprises arranging the plurality of radial arms in a cross-shaped configuration, or arranging the plurality of radial arms in a star-shaped configuration, or arranging the plurality of radial arms in any combination thereof.

[0036] TECHNICAL SOLUTION 16. The method of any preceding technical solution, wherein the joining of the plurality of tubular structures to the spacer element comprises: joining a first tubular structure of the plurality of tubular structures to a first thin-walled bracket portion of the spacer element; joining a second tubular structure of the plurality of tubular structures to a second thin-walled bracket portion of the spacer element; and joining the first thin-walled bracket portion and the second thin-walled bracket portion at a top end of the spacer element and at a bottom end of the spacer element, and spatially separating the plurality of tubular structures from one another comprises spatially separating the first thin-walled bracket portion and the second thin-walled bracket portion by a hollow space between the first thin-walled bracket portion and the second thin-walled bracket portion.

[0037] TECHNICAL SOLUTION 17. The method of any preceding technical solution, wherein the joining of the plurality of tubular structures to the spacer element comprises: joining a first tubular structure of the plurality of tubular structures to a first cradle bracket portion of the spacer element; joining a second tubular structure of the plurality of tubular structures to a second cradle bracket portion of the spacer element; and joining the first cradle bracket portion, the second cradle bracket portion, and a core portion of the spacer element at a top end of the spacer element and at a bottom end of the spacer element, and spatially separating the plurality of tubular structures from one another comprises spatially separating the first cradle bracket portion and the second cradle bracket portion by the core portion positioned between the first cradle bracket portion and the second cradle bracket portion.

[0038] Technical Solution 18. The method according to any of the foregoing technical solutions, wherein the extension of the fastening element includes rounding the following portions: a first joint between the first bracket bracket portion and the top end, or a second joint between the second bracket bracket portion and the top end, or a third joint between the first bracket bracket portion and the bottom end, or a fourth joint between the second bracket bracket portion and the bottom end, or any combination thereof.

[0039] Technical Solution 19. The method according to any of the foregoing technical solutions, wherein the extension of the fastening element comprises: receiving a first portion of the fastening element in a first recess between the first bracket bracket portion and a first corresponding surface of the core portion; and receiving a second portion of the fastening element in a second recess between the second bracket bracket portion and a second corresponding surface of the core portion.

[0040] Technical Solution 20. The method according to any of the foregoing technical solutions, wherein the engagement of each of the plurality of tubular structures to the spacer element comprises: connecting a first tubular structure and a first bracket bracket portion of the plurality of tubular structures at a first contact surface; connecting a second tubular structure and a second bracket bracket portion of the plurality of tubular structures at a second contact surface, and the distribution of stress in the plurality of tubular structures comprises providing a plurality of surface features on the first contact surface or the second contact surface or on both the first contact surface and the second contact surface, and the provision of the plurality of surface features comprises providing a plurality of protrusions, or recesses, or any combination thereof. Attached Figure Description

[0041] The features and advantages of this disclosure will be apparent from the following description of various exemplary embodiments illustrated in the accompanying drawings, wherein similar reference numerals generally indicate the same, functionally similar and / or structurally similar elements.

[0042] FIG. 1A A schematic perspective view of a tube spacer and fastening system for a tubular structure according to an embodiment of the present disclosure is shown.

[0043] FIG. 1B An embodiment of the present disclosure is shown for use with FIG. 1A Enlarged schematic perspective front view of the spacers in the pipe spacing and fastening system.

[0044] FIG. 1C An embodiment of the present disclosure is shown for use with FIG. 1A Enlarged schematic perspective rear view of the spacers in the pipe spacing and fastening system.

[0045] FIG. 2AA schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0046] FIG. 2B A schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure. FIG. 2A A schematic perspective view of a spacer of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0047] FIG. 3A A schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0048] FIG. 3B A schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure. FIG. 3A A zoomed-in schematic perspective view of a spacer of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0049] FIG. 4 A schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0050] FIG. 5 A schematic perspective view of a pipe spacer and fastening system for tubular structures is shown in accordance with embodiments of the present disclosure.

[0051] FIG. 6A A partial perspective view of a spacer of a pipe spacer and fastening system is shown in accordance with embodiments of the present disclosure.

[0052] FIG. 6B A partial perspective view of a spacer of a pipe spacer and fastening system is shown in accordance with embodiments of the present disclosure.

[0053] FIG. 6C A partial perspective view of a spacer of a pipe spacer and fastening system is shown in accordance with embodiments of the present disclosure.

[0054] FIG. 7 A schematic flow diagram of a method of spacing and fastening a plurality of tubular structures is shown in accordance with embodiments of the present disclosure. DETAILED DESCRIPTION

[0055] The features, advantages, and embodiments of the present disclosure are set forth with particularity in the detailed description that follows, accompanied by the accompanying drawings and the claims. Furthermore, it should be understood that the detailed description is intended to provide further explanation of the disclosure as claimed, and is not intended to limit the scope of the disclosure as claimed.

[0056] Various embodiments are discussed in detail below. While specific implementations are discussed, this is simply for illustration purposes and other components and configurations can be utilized by one skilled in the relevant art without departing from the spirit and scope of this disclosure.

[0057] Reference will now be made in detail to the presently preferred embodiments of the disclosed subject matter, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations that correspond to the drawings in which it is drawn. Like or similar designations in the drawings and description have been used to indicate like or similar portions of the disclosed subject matter. As used herein, the terms "first," "second," "third," "fourth," and "exemplary" can be used interchangeably to distinguish one component from another and are not meant to signify location or importance of the individual components.

[0058] Further, to describe and clearly and without prejudice to the scope of the subject matter, the following definitions are provided for specific terms used throughout the description and the appended claims, unless specifically stated otherwise with respect to a particular embodiment. The term "pipe spacing and fastening system" as used in context refers to a set of interacting or interrelated elements that function according to a set of rules to form a unified whole that is deployed to spatially separate pipes or their equivalents, such as conduits, poles, rods, or any tubular structure, and simultaneously fastens them together. The detailed description uses numerical and letter designations to refer to features of the pipe spacing and fastening system in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar pipe spacing and fastening systems. As used herein, the numbers "20," "40," "60," and "80" can be used interchangeably to distinguish one system from another and are not meant to signify location or importance of the individual systems.

[0059] The term "spacer element" as used in context refers to a device or piece used to form or maintain a desired amount of space between two or more objects. The detailed description uses numerical and letter designations to refer to features of the spacer element in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar spacer elements. As used herein, the numbers "22," "42," "62," and "82" can be used interchangeably to distinguish one spacer element from another and are not meant to signify location or importance of the individual spacer elements.

[0060] The term "core portion" as used in context refers to the central and foundational portion of a spacer element, typically distinguished from the sheath portion by differences in properties or structure or function. The detailed description uses numerical and letter designations to refer to features of the core portion in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar core portions. As used herein, the numbers "29," "45," and "86" can be used interchangeably to distinguish one core portion from another and are not meant to signify location or importance of the individual core portions.

[0061] The term "fastener element" as used in context refers to a device or component that structurally links or affixes two or more objects together. Generally, fasteners are used to form non-permanent joints, i.e., joints that can be removed or disassembled without damaging the linked components. The detailed description uses numerical and letter designations to refer to features of fastener elements in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous fastener elements. As used herein, the numbers "23," "46," "72," and "92" can be used interchangeably to distinguish one fastener element from another and are not intended to indicate the position or importance of the individual fastener elements.

[0062] The term "raised slot edge" as used in context refers to the raised sides of a narrow, elongated recess, groove, notch, slit, or aperture, especially a narrow opening on a spacer element, for receiving or accepting something having a planar dimension, such as a fastener strip or band. The detailed description uses numerical and letter designations to refer to features of raised slot edges in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous raised slot edges. As used herein, the numbers "54" and "68" can be used interchangeably to distinguish one raised slot edge from another and are not intended to indicate the position or importance of the individual raised slot edges.

[0063] The term "top end" as used in context refers to the highest or uppermost point, portion, or surface of a spacer element. The detailed description uses numerical and letter designations to refer to features of top ends in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous top ends. As used herein, the numbers "37" and "65" can be used interchangeably to distinguish one top end from another and are not intended to indicate the position or importance of the individual top ends.

[0064] Similarly, the term "bottom end" as used in context refers to the lowest or lowermost point, portion, or surface of a spacer element. The detailed description uses numerical and letter designations to refer to features of bottom ends in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous bottom ends. As used herein, the numbers "38" and "66" can be used interchangeably to distinguish one bottom end from another and are not intended to indicate the position or importance of the individual bottom ends.

[0065] The term "top tray slot" as used in context refers to a narrow, elongated recess, groove, notch, slit, or aperture, especially a narrow opening on the top of a spacer element, for receiving or taking in something having a planar dimension, such as a fastening strip or band. The detailed description uses numerical and letter designations to refer to features of the top tray slots in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous top tray slots. As used herein, the numbers "52" and "67" can be used interchangeably to distinguish one top tray slot from another, and are not intended to indicate the location or importance of the respective top tray slots.

[0066] The term "tube outer surface" as used in context refers to the outermost or uppermost or external boundary or layer or region of a tube. The detailed description uses numerical and letter designations to refer to features of the tube outer surfaces in the drawings. Similar or analogous designations in the drawings and the description have been used to refer to similar or analogous tube outer surfaces. As used herein, the numbers "26," "47," "73," and "93" can be used interchangeably to distinguish one tube outer surface from another, and are not intended to indicate the location or importance of the respective tube outer surfaces.

[0067] The tube spacing and fastening system of the present disclosure provides for coupling a plurality of tubular structures together. The tube spacing and fastening system of the present disclosure couples or connects a plurality of tubular structures together without the need for brazing or welding. In some examples, the tube spacing and fastening system can include a spacer element and a fastening band for coupling a plurality of tubular structures. The spacer element functionally resolves the engineering paradox of holding the tubular structures together and at the same time spatially separating them from one another. The fastening band extends around the outer surfaces of the tubular structures and loosely fastens to the spacer element below a predetermined temperature range and tightly fastens to the spacer element above a predetermined temperature range.

[0068] The spacer element is also configured to distribute stress in each of the plurality of tubular structures relative to the spacer element. Surface features can be present on the spacer. Further, the tube spacing and fastening system of the present disclosure can allow for coupling a plurality of tubular structures in a manner that reduces, prevents, or eliminates high stress concentrations.

[0069] Gas turbine engine equipment includes tubes or conduits that carry fuel, oil, hydraulic fluid, and pressurized air. The tubes or conduits are typically bundled together to carry fluids within or across several compartments and components of the engine, such as the fan, compressor, turbine, or to vent fluids out of the engine. Tube or pipe assemblies found in engineering components deployed in aircraft engine, heat exchanger, and nuclear power structures typically use spacers to bundle the tubes together. The spacers can be permanently joined to the tube bundle, for example, with brazing or welding tabs. For example, a typical tube assembly of an exemplary tubular structure can include, in a non-limiting manner, tubes, pipes, rods, bars, or combinations thereof. In one example, an exemplary tube assembly can include a set of exemplary tubes permanently joined (e.g., brazed or welded) in a clamp forming a clamp-tube assembly. In one example, an exemplary tube assembly can include a set of exemplary tubes permanently joined (e.g., brazed or welded) in a spacer forming a permanently joined spacer-tube assembly.

[0070] FIG. 1A A schematic perspective view of a tube spacing and fastening system for tubular structures, such as tubes, pipes, rods, and bars, typically found in engineering components associated with aircraft engines, is shown in accordance with embodiments of the present disclosure. Referring to FIG. 1A A set of exemplary tubes 12 are assembled in a tube spacing and fastening system 20. The tube spacing and fastening system 20 can include a spacer element 22 configured to engage the exemplary tubes 12 and spatially separate one exemplary tube 12a from another exemplary tube 12b. The spacer element 22 can spatially separate the exemplary tubes 12 and distribute stresses in the tube spacing and fastening system 20. Further, a fastening element 23 is configured to extend around at least a portion of an outer surface 26 of the exemplary tubes 12, and the fastening element 23 is configured to extend around at least a portion of the outer surface 26 of the exemplary tubular structures 12 and fasten the exemplary tubes 12 to the spacer element 22 in an adaptive spacing configuration. In one example, the adaptive spacing configuration can include a first length of the fastening element 23 below a predetermined temperature range and a second length of the fastening element 23 above the predetermined temperature range, such that the first length is different from the second length. Further, in another example, the adaptive spacing configuration can include a first configuration in which the exemplary tubes 12 are movably spaced around the spacer element 22 and a second configuration in which the exemplary tubes 12 are immovably spaced around the spacer element 22.

[0071] FIG. 1B An enlarged schematic perspective front view of a spacer element 22 as in the tube spacing and fastening system 20 of exemplary tubes 12 as in FIG. 1A FIG. 1C An enlarged schematic perspective front view of a spacer element 22 as in the tube spacing and fastening system 20 of exemplary tubes 12 as in​FIG. 1A enlarged schematic perspective rear view of a spacer element 22 of a tube spacing and fastening system 20. Reference is made to FIG. 1B and FIG. 1C , the spacer element 22 can include two opposing faces, a first cradle bracket 27 and a second cradle bracket 28, separated by a core portion 29 positioned in the center of the spacer element 22 and between the first cradle bracket 27 and the second cradle bracket 28. The first cradle bracket 27, the second cradle bracket 28, and / or the core portion 29 can be concave, or can be any shape configured to complement the shape of the exemplary tubes 12. In one example, the core portion 29 can be a bi-concave core portion. The spacer element 22 can be a spacer block and can be a solid block. The first cradle bracket 27 and the second cradle bracket 28 can be formed in the body of the spacer element 22.

[0072] With continued reference to FIG. 1B and FIG. 1C , the first contact surface 30 can engage a corresponding first exemplary tube 12a( FIG. 1A ) at the first cradle bracket 27, and the second contact surface 31 can engage a corresponding second exemplary tube 12b( FIG. 1A ) at the second cradle bracket 28. The first contact surface 30, the second contact surface 31, or both, can include a plurality of exemplary surface features 32, such as, for example and without limitation, dimples or protrusions.

[0073] In more detail, the spacer element 22 employs the first cradle bracket 27 configured to engage the first exemplary tube 12a( FIG. 1A ) and the second cradle bracket 28 configured to engage the second exemplary tube 12b( FIG. 1A ). The core portion 29 spatially separates the first cradle bracket 27 from the second cradle bracket 28, and thus spatially separates the first exemplary tube 12a engaged in the first cradle bracket 27 from the second exemplary tube 12b engaged in the second cradle bracket 28. The spacer element 22 further includes a first recess 33 on one side, engraved between the first cradle bracket 27 and a first corresponding surface 35 of the core portion 29. In a similar manner, the spacer element 22 further includes a second recess 34 on the other side, engraved between the second cradle bracket 28 and a second corresponding surface 36 of the core portion 29.

[0074] The first recess 33 is configured to accommodate the first portion 24( FIG. 1A ) of the fastening element 23, and the second recess 34 is configured to accommodate the second portion 25( FIG. 1A ) of the fastening element 23. Each of the first recess 33 and the second recess 34 includes a protruding lip 49FIG. 1B and FIG. 1C ) and the seat 51 ( FIG. 1B and FIG. 1C ), which together hold the fastening element 23 under stress within the respective recesses 33 and 34 and prevent slipping out of the recesses. With continued reference to FIG. 1B and FIG. 1C , the first bracket bracket 27, the second bracket bracket 28 and the core portion 29 can be joined at the top end 37 of the spacer element 22 and at the bottom end 38 of the spacer element 22.

[0075] In embodiments of the present disclosure, the fastening element 23 can be a wrap-around band made of a shape memory alloy (SMA). Without being bound by any particular theory, it is presently believed that the scientific effect of exemplary shape memory alloys is based on the phenomenon that the martensitic phase appears and disappears continuously as the temperature decreases and increases. This thermoelastic behavior is the result of a transition from the original austenitic phase, which is stable at elevated temperatures, to the martensitic phase. Specifically, when a pre-deformed shape memory alloy sample is heated to the temperature of the original austenitic phase, full recovery of the deformation occurs. Full recovery in this process is limited by the fact that the strain must not exceed a critical value, which ranges, for example, from 3% to 4% for copper shape memory effect alloys to 6% to 8% for nickel-titanium shape memory alloys.

[0076] As implemented by the fastening element 23 as an SMA band, the shape memory effect is a spontaneous, reproducible, and reversible shape change associated with heating and cooling throughout the entire transition temperature range. Furthermore, it is possible to condition or "train" the shape memory alloy to have the shape memory effect by repeating the cooling and heating process multiple times. For example, the reversible shape change can be lengthening and shortening when the trained shape memory alloy sample is cycled between two transition temperatures.

[0077] Referring to FIG. 1A When the fastening element 23 is a shape memory alloy band, the fastening element 23 of the present disclosure can have an entire transition temperature range above atmospheric temperature and below a certain temperature, such that the shape memory alloy band can assume a first configuration (length) for tightly supporting the exemplary pipe 12 at temperatures above the entire transition temperature, and a second configuration (length) for loosely engaging the exemplary pipe 12 below the entire transition temperature. Thus, to engage the exemplary pipe 12 with the spacer element 22, the shape memory alloy band can generate a high radial compression force that swages the underlying exemplary pipe 12.

[0078] In operation, when the fastening element 23 is a shape memory alloy (SMA) band, the band is configured to be oversized in a cooled martensitic state, and then during operation, the band is heated to a smaller contracted size to generate an elastic radial compression force and thereby engage the exemplary pipe 12 with the spacer element 22. Further, with reference to FIG. 1A In one embodiment of the present disclosure, the shape memory alloy (SMA) band generates a high radial compression force and presses (compresses or crumples) the underlying pipe surface to locally yield at the static metal-to-metal joint by pressing a plurality of surface features (bumps or dimples or teeth or shallow indentations or ridges) configured on the contact surface and simultaneously maintains continuous contact with the spacer element 22.

[0079] Any shape memory alloy can be used in the present disclosure, provided it exhibits sufficient shape memory effect. In one embodiment of the present disclosure, the shape memory alloy comprises a nickel-titanium alloy, the weight ratio of which is selected to deform at a temperature higher than the desired transition temperature. Further, the chemical composition and transition temperature of the shape memory metal (SMA) is further selected to be suitable for the desired pipe spacing and fastening system operating temperature between ambient temperature and about 1000 °F.

[0080] Thus, the exemplary shape memory alloy (SMA) band for FIG. 1A the fastening element 23 utilizes their shape memory properties and corresponding configured and memorized length to provide a temperature sensitive length change and thus a significant degree of adaptive spacing of the exemplary pipe 12 during operation. Specifically, when the exemplary pipe 12 is at its operating temperature which is higher than the transition temperature of the shape memory alloy (SMA) band, the typical shape memory alloy (SMA) band transitions to its memorized shorter length, thereby providing a tight and reduced spacing and lateral load on the exemplary pipe 12. With reference to FIG. 1A , FIG. 1B and FIG. 1C the shape memory alloy (SMA) band of the fastening element 23 of the present disclosure can be heated above the original austenite transition temperature range to the high temperature, tight configuration shape memory alloy engagement of the first and second bracket bracket portions 27 and 28 and the outer surface 26 of the exemplary pipe 12.

[0081] In contrast, once cooled below the martensitic transformation temperature range, typical shape memory alloy (SMA) bands shift to their low temperature configuration and are at an expanded length or stretched length or over-length corresponding to the lower temperature. Typically, such high temperature configurations are associated with operating conditions when the exemplary tube 12 needs to be in compact, tight, and immovable contact. In addition, the low temperature configuration is associated with maintenance or shutdown of the engineered spacer and fastening system, and the shape memory alloy (SMA) bands enable a relaxed configuration that enables the exemplary tube 12 to be slidably or moveably disengaged from its respective cradle bracket and spacer element 22. The shape memory alloy (SMA) bands and their shape memory effect thus inherently provide the exemplary tube 12 with adaptive spacing relative to each other and to the spacer element 22 to which they are fastened.

[0082] The stress distribution effect of the shape memory alloy (SMA) bands can be further enhanced by employing stress-adaptive configurations of the spacer element 22 and related portions and components. For example, the contact surfaces (e.g., the first contact surface 30 and / or the second contact surface 31) where two or more portions engage and / or interact with each other can include stress-adaptive configurations (e.g., surface features configured to reduce contact stress between the portions). In another embodiment of the disclosure, one or more or all of the joints 39 in the spacer element 22 are filleted at the corners where the fasteners 23 engage the spacer element 22 for optimal stress distribution. In other words, the first exemplary joint 39a between the first cradle bracket 27 and the top end 37, the second exemplary joint 39b between the second cradle bracket 28 and the top end 37, the third exemplary joint 39c between the first cradle bracket 27 and the bottom end 38, and the fourth exemplary joint 39d between the second cradle bracket 28 and the bottom end 38 are all filleted joints.

[0083] Referring to FIG. 1A , FIG. 1B and FIG. 1C , the exemplary tube 12 has a diameter in the range of 0.75 to 1.0 inches and a wall thickness in the range of 0.020 to 0.035 inches. The width of the spacer element 22 has approximately 0.5 inches, and the thickness of the shape memory alloy (SMA) bands is in the range of 0.020 to 0.063 inches.

[0084] With continued reference to FIG. 1B and FIG. 1C, the additional stress distribution configuration can include contouring the first and second contact surfaces 30, 31 between the exemplary tube 12 and the first and second bracket bracket portions 27, 28, respectively. Thus, instead of full surface contact between a stiffer block (e.g., spacer element 22) and a thin walled tube (e.g., exemplary tube 12) generating higher edge contact stresses, the spacer element 22 can include exemplary surface features 32. The exemplary surface features 32 can be protrusions (also referred to as "bumps") in one example, and dimples (also referred to as "dimples") in another example. In yet another example, the surface features 32 can be any combination of protrusions and dimples. The exemplary surface features 32 can have different shapes with different cross sections, such as spherical-circular (as shown in FIG. 1B and FIG. 1C . Thus, the exemplary surface features 32 can create a low stress field at discrete contact points on the exemplary tube 12. Specifically, the first exemplary tube 12a joins the first bracket bracket portion 27 at the first contact surface 30, and the second exemplary tube 12b joins the second bracket bracket portion 28 at the second contact surface 31, and the first or second contact surfaces 30, 31, or both, include exemplary surface features 32 that can include protrusions and / or dimples that can provide an effective stress optimization configuration. Thus, with reference to FIG. 1A , FIG. 1B and FIG. 1C , metal-to-metal contact at the "thick walled" first bracket bracket portion 27 and "thick walled" second bracket bracket portion 28 can result in high stresses, thus the exemplary surface features 32 (protrusions / dimples) can be included in a non-limiting manner. In other words, if desired, the exemplary surface features 32 (protrusions / dimples) can be omitted in another example.

[0085] FIG. 2A A schematic perspective view of a tube spacing and fastening system 40 for exemplary tubes 12 according to embodiments of the present disclosure is shown. With reference to FIG. 2A , the tube spacing and fastening system 40 includes a spacer element 42 having two opposing faces shaped as a first bracket bracket portion 43 and a second bracket bracket portion 44 separated by a core portion 45. In embodiments of the present disclosure, the outer surfaces of the first and second bracket bracket portions 43, 44 can be marked with exemplary surface features including protrusions / dimples (not visible, such as described with respect to FIG. 1B and FIG. 1C . With continued reference to FIG. 2AThe fastening element 46 extends around at least a portion of the outer surface 47 of each of the exemplary tubes 12 in the tube spacer and fastening system 40 to fasten the exemplary tube 12 to the spacer element 42. In one example, the fastening element 46 may be a shape memory alloy (SMA) strip.

[0086] FIG. 2B Examples of embodiments according to this disclosure are shown in use for FIG. 2A An enlarged schematic perspective view of the spacer element 42 in the exemplary tube 12 tube spacer and fastening system 40. (Continue referring to...) FIG. 2B The spacer element 42 is constructed as a solid block, which includes a seating slot or recess 52 for receiving a fastening element 46 implemented as a shape memory alloy (SMA) strip. The fastening element 46 implemented as a shape memory alloy (SMA) strip typically extends around the spacer element 42 and the exemplary tube 12. Furthermore, the seating slot or recess 52 may include a raised edge 54 on the spacer element 42 to provide a secure or fitted seating arrangement for the fastening element 46 implemented as a shape memory alloy (SMA) strip within the seating slot or recess 52.

[0087] Continue to refer to FIG. 2B Additional stress distribution configurations may include contouring the contact surfaces between the exemplary tube 12 and the first bracket bracket 43 and the second bracket bracket 44. Therefore, instead of full-surface contact between a harder block (e.g., spacer element 42) and a thin-walled tube (e.g., exemplary tube 12) that generates higher edge contact stress, spacer element 42 may include exemplary surface features (not shown). In one instance, the exemplary surface feature may be a protrusion (also referred to as a “bead”), and in another instance, a dimple (also referred to as a “shallow dimple”). In yet another instance, the surface feature may be any combination of protrusions and dimples. Thus, the exemplary surface feature may generate a low stress field at discrete contact points on the exemplary tube 12. Specifically, the first exemplary tube 12a is connected to the first bracket bracket 43 at a corresponding first contact surface (not shown), and the second exemplary tube 12b is connected to the second bracket bracket 44 at a corresponding second contact surface (not shown). The first contact surface or the second contact surface, or both, include exemplary surface features that may include protrusions and / or recesses, which can provide an effective stress distribution configuration. Therefore, referring to... FIG. 2A and FIG. 2B Metal-to-metal contact at the bracket portion 43 of the "thick-walled" first bracket and the bracket portion 44 of the "thick-walled" second bracket can result in high stress, therefore the exemplary surface features (protrusions / dimples) can be included in a non-limiting manner. In other words, it is desirable that the exemplary surface features (protrusions / dimples) be omitted in another instance.

[0088] FIG. 3A A schematic perspective view of a pipe spacing and fastening system 60 for exemplary pipes 12 is shown in accordance with an embodiment of the present disclosure. Reference is made to FIG. 3A A set of exemplary pipes 12 are assembled in the pipe spacing and fastening system 60. The pipe spacing and fastening system 60 includes a spacer element 62 having two opposite faces shaped as a first thin-walled bracket 63 and a second thin-walled bracket 64. In one embodiment of the present disclosure, the outer surfaces of the first thin-walled bracket 63 and the second thin-walled bracket 64 are marked with protrusions and / or recesses (not shown), such as described with respect to FIG. 1B and FIG. 1C The thin-walled bracket 64 and the thin-walled bracket 63 can function as a cradle, such as described with respect to FIG. 1A to FIG. 2B so that FIG. 3A and FIG. 3B The pipe spacing and fastening system 60 of

[0089] FIG. 3B An enlarged schematic perspective view of a spacer element 62 as part of a pipe spacing and fastening system 60 for exemplary pipes 12 is shown in accordance with an embodiment of the present disclosure. Reference is made to FIG. 3A , the spacer element 62 has a top end 65, a bottom end 66, and a top tray slot 67 with a raised slot edge 68. Further reference is made to FIG. 3B and FIG. 3A and FIG. 3B A fastening element 72 implemented as a shape memory alloy (SMA) band extends around the outer surface 73 of the exemplary pipes 12 in the pipe spacing and fastening system 60 to fasten them to the spacer element 62.

[0090] The pipe spacing and fastening system 60 can include a spacer element 62 having two opposite faces shaped as a first thin-walled bracket 63 and a second thin-walled bracket 64. In another embodiment of the present disclosure, the first thin-walled bracket 63 is configured to engage a first exemplary pipe 12a, and the second thin-walled bracket 64 is configured to engage a second exemplary pipe 12b. The first thin-walled bracket 63 and the second thin-walled bracket 64 are joined to each other at a top end 65 on a top of the spacer element 62, and further joined to each other at a bottom end 66 of the spacer element 62. Further, the first thin-walled bracket 63 and the second thin-walled bracket 64 are spatially separated by a hollow space between the first thin-walled bracket 63 and the second thin-walled bracket 64.

[0091] Reference is made to FIG. 3A and FIG. 3B, the additional stress distribution configuration can include contouring the contact surface between the exemplary tube 12 and the first thin-walled bracket portion 63 and the second thin-walled bracket portion 64. Thus, instead of full surface contact between the stiffer block (e.g., spacer element 62) and the thin-walled tube (e.g., exemplary tube 12) that generates a higher edge contact stress, the spacer element 62 can include exemplary surface features (not shown). The exemplary surface features can be protrusions (also referred to as "bumps") in one example, and dimples (also referred to as "dimples") in another example. In yet another example, the surface features can be any combination of protrusions and dimples. Thus, the exemplary surface features can create a low stress field at discrete contact points on the exemplary tube 12. In particular, the first exemplary tube 12a joins the first thin-walled bracket portion 63 at a corresponding first contact surface (not shown), and the second exemplary tube 12b joins the second thin-walled bracket portion 64 at a corresponding second contact surface (not shown), and the first or second contact surfaces or both include exemplary surface features that can include protrusions and / or dimples that can provide an effective stress distribution configuration. Thus, with reference to FIG. 3A and FIG. 3B , the metal-to-metal contact at the first thin-walled bracket portion 63 and the second thin-walled bracket portion 64 can not result in high stress, and thus the exemplary surface features 32 can not be included in a non-limiting manner. However, in another example, the exemplary surface features 32 can be included and formed as protrusions / dimples as desired in order to reduce existing stress.

[0092] FIG. 4 is a schematic perspective view of a tube spacing and fastening system 80 for exemplary tubes 12 according to embodiments of the present disclosure. With reference to FIG. 5 , the tube spacing and fastening system 80 includes a spacer element 82. The spacer element 82 can be any predetermined configuration, such as a star-shaped configuration, or a cross-shaped configuration, or any combination thereof. The spacer element 82 can include one or more radial arms 84 arranged in a star-shaped configuration. Further, each of the radial arms 84 is joined at its respective base with a core portion 86. The radial arms 84 and the core portion 86 can be unitary and integral, or can be separate portions that are coupled or connected together. In FIG. 4 a non-limiting example, there are four exemplary radial arms 84 extending from the core portion 86, but in other embodiments, there can be fewer than or more than four radial arms 84. The number of radial arms 84 can be selected based on the number of exemplary tubes 12 that are desired to be coupled together.

[0093] With continued reference to FIG. 4, an exemplary pair of adjacent radial arms 84a and 84b (two adjacent radial arms) and the core portion 86 joined at their respective bases can form an exemplary cradle bracket 88 to engage a corresponding tubular structure that is embodied as an outer surface 93 of an exemplary tube 12. Thus, in the example of FIG. 5 , FIG. 1B 、 FIG. 1C 、 FIG. 2B 、 FIG. 3B and FIG. 6A to FIG. 6C , FIG. 4 , a fastening element 92 embodied as a shape memory alloy (SMA) band can extend around the outer surface 93 of each of the exemplary tubes 12 in the tube spacing and fastening system 80 to fasten the tubes to the exemplary star-shaped configuration, or cross-shaped configuration, or any combination thereof, of the spacer element 82.

[0094] FIG. 5 is a schematic perspective view of a tube spacing and fastening system 100 for exemplary tubes 12 according to an embodiment of the present disclosure. Referring to FIG. 6, the tube spacing and fastening system 100 includes a spacer element 182. The spacer element 182 includes three exemplary radial arms 184a, 184b, and 184c arranged in a star-shaped configuration. Each of the radial arms 184a, 184b, and 184c is joined at its respective base with a core portion 186. The radial arms 184a, 184b, and 184c and the core portion 186 can be unitary and integral, or can be separate portions coupled or connected together.

[0095] Continuing to refer to FIG. 5 , an exemplary pair of adjacent radial arms 184b and 184c (two adjacent radial arms) and the core portion 186 joined at their respective bases form an exemplary cradle bracket 188 to engage a corresponding tubular structure that is embodied as an outer surface 193 of an exemplary tube 12. Thus, in the example of FIG. 5 , three cradle brackets 188 are formed to accommodate three exemplary tubes— a first exemplary tube 12a, a second exemplary tube 12b, and a third exemplary tube 12c. The outer surfaces (e.g., the surfaces that form the cradle brackets 188) of the radial arms 184a, 184b, and 184c are marked with surface features including protrusions / recesses (not shown), such as described with respect toFIG. 1B 、 FIG. 1C 、 FIG. 2B 、 FIG. 3B and FIG. 6A to FIG. 6C described. With continued reference to FIG. 5 , the fastening elements 192, which are implemented as shape memory alloy (SMA) bands, extend around the outer surface 193 of each of the example tubes 12a, 12b, and 12c to fasten the tubes to the spacer element 182.

[0096] FIG. 6A to FIG. 6C An example surface feature 32 is shown, which can be provided in any or all of the spacer elements described herein, such as, for example, the spacer element 22( FIG. 1C ), the spacer element 42( FIG. 2A ), the spacer element 62( FIG. 3A ), the spacer element 82( FIG. 4 ), and the spacer element 182( FIG. 5 ). The example surface feature 32 can be a prismatic surface feature 32a( FIG. 6A ), an elongated rectangular surface feature 32b( FIG. 6B ), or a rounded hemispherical surface feature 32c( FIG. 6C ). Other shapes are also contemplated, such as, for example, a cube or other polygon, an ellipse, a square, a trapezoid, a triangle, an elongated curved shape, a continuous shape, a discrete shape, etc. Any combination of the illustrated surface features and / or described surface features can be provided on the spacer elements of the present disclosure. The surface features 32 can be protrusions, indentations, or a combination thereof. More than one shape of surface feature 32 can be provided on a single bracket surface of a spacer element. More than one shape of surface feature 32 can be provided on different bracket surfaces of a single spacer element. The surface features 32 described herein can be formed using additive manufacturing, electrical discharge texturing, or electroforming.

[0097] With reference to FIG. 1A to FIG. 6C , the spacer element 22, the spacer element 42, the spacer element 62, the spacer element 82, and the spacer element 182 can be additively manufactured. Further, in particular, the spacer element 22, the spacer element 42, the spacer element 62, the spacer element 82, and the spacer element 182 can optionally be contoured with shallow dimples / ridges / beads by additive manufacturing in an economical manner. In other embodiments of the present disclosure, other manufacturing methods such as traditional subtractive manufacturing can be employed to produce the parts from typical machined blocks. As for the material of the spacer and fastening system, the spacer elements 22, 42, 62, and 82 are made of steel, Inconel®, or other suitable metal, such as Nitinol (Ni-Ti), which meets high temperature applications and provides inherent elasticity to maintain the required extension strength for the brazeless and weldless joints.

[0098] Any of the spacer blocks, fastening elements, and spacer and fastening systems described herein can be combined with all or portions of other spacer blocks, fastening elements, and spacer and fastening systems described herein. Although a single spacer and fastening system is shown for the exemplary pipe 12, more spacer and fastening systems can be provided along the length of the exemplary pipe 12. In this manner, the pipe spacer and fastening system of the present disclosure can include multiple spacer blocks and fastening elements. This number can be selected based on the desired coupling and securing of the exemplary pipe 12.

[0099] FIG. 7 is a block diagram of a method 200 of spacing and fastening a tubular structure according to one embodiment of the present disclosure. Referring to FIG. 7 , the method 200 of spacing and fastening a tubular structure, such as the exemplary pipe 12, includes providing a spacer element in step 202, joining a plurality of tubular structures to the spacer element in step 204, spatially separating the plurality of tubular structures from one another in step 206, and distributing stress in the plurality of tubular structures in step 208. The method 200 further includes extending a fastening element around at least a portion of an outer surface of the plurality of tubular structures in step 212, and fastening the plurality of tubular structures to the spacer element in an adaptively spaced configuration in step 214.

[0100] In another embodiment of the present disclosure, the method 200 of spacing and fastening a pipe further includes non-permanently joining a first exemplary pipe 12a to a first cradle bracket portion FIG. 1B and FIG. 1C , 27; FIG. 2A , 43; FIG. 3A , 63; FIG. 4 , 88; FIG. 5 , 188); joining a second exemplary pipe 12b to a second cradle bracket portion FIG. 1B and FIG. 1C , 28; FIG. 2A , 44; FIG. 3A , 64; FIG. 4 , 88; FIG. 5 , 188), such that the first exemplary pipe 12a and the second exemplary pipe 12b are spatially separated.

[0101] In one aspect of the disclosure, the pipe spacing and fastening system of the present disclosure uses suitable fastening elements to space and fasten the pipes and / or tubes without any cutting or shearing of the structural integrity of the pipes and / or tubes and / or the pipe and / or tube. Thus, the spacing and fastening elements as described in embodiments of the present disclosure improve several key operational performance factors, including high stress concentration (Kt) at the pipe joint, difficulty in controlling uniformity of quality (due to voids, limited brazing / weld witness features, and lack of coverage), low high cycle fatigue (HCF) capability of the material flux, geometric stress concentration, and rapid transition from the flexible pipe surface to the rigid restraining element.

[0102] Although described as joining exemplary pipes 12, in one example, the connection provided by the spacer element and the fastening element can be permanent. In other examples, the connection provided by the spacer element and the fastening element to join exemplary pipes 12 can be non-permanent. In some embodiments, the spacer element and the fastening element can be retrofitted onto exemplary pipes 12. The spacer element and the fastening element can be capable of being serviceable or replaceable in a manufacturing plant or in the field.

[0103] The pipe spacing and fastening system of the present disclosure can include a shape memory alloy (SMA) band as the fastening element, which provides advantages compared to permanently linked spacer and fastening system configurations, which sometimes hold the pipes too firmly during pipe reconfiguration and / or tend to scratch the pipes during installation.

[0104] The pipe spacing and fastening system of the present disclosure provides a non-brazed, non-welded connection or coupling of the pipes. The use of a shape memory alloy (SMA) band for connecting the pipes and the spacer element in a non-brazed, non-welded pipe bundle configuration can address issues associated with stress concentration of brazed or welded joints. The shape memory alloy (SMA) band extending around the pipes linked at the spacer element provides a smooth stress distribution without any abrupt transition in stiffness from the spacer element to the pipes.

[0105] The pipe spacing and fastening system of the present disclosure can provide adaptive spacing and fastening and deconstruction by employing a thermo-elastic compressive shape memory alloy (SMA) band that continues to maintain continuous contact of the pipe bundle with the spacer element even in the case of contact wear, which is common for non-brazed and non-welded pipe bundle configurations.

[0106] The pipe spacing and fastening system of the present disclosure includes a shape memory alloy (SMA) band as a fastening element, which is provided with a memory length and is generally produced and installed around the pipes so as to provide pipe adaptive spacing. When the shape memory alloy (SMA) band is at its operating temperature, which is above the shape memory alloy (SMA) band's transition temperature, the shape memory alloy (SMA) band transitions to the memory length, thereby providing a reduced spacing and lateral load for the pipes. Thus, the shape memory alloy (SMA) band inherently provides adaptive spacing for the pipes in the pipe bundle relative to each other and the spacer element.

[0107] Exemplary shape memory alloys can include any Ni-Ti, or Ni-Ti-Hf, or Ni-Ti-Pd, or Ti-Au-Cu alloys.

[0108] Any of the fastening elements of the present disclosure can be a shape memory alloy band. The shape memory alloy band operates as a fastener to isolate a joint assembly of one or more tubular structures. In some examples, the shape memory alloy (SMA) properties improve the reliability and performance of the pipe assembly compared to conventional metallic fasteners. The shape memory alloy (SMA) band enables a high performance and reliable isolated joint assembly through stress-induced martensitic transformation in the shape memory alloy (SMA) band fastener. For example, the shape memory alloy (SMA) band has super-elasticity, variable stiffness, and high energy dissipation. These features can provide the following benefits:

[0109] Super-elasticity: NiTi-based shape memory alloy (SMA) bands exhibit super-elastic behavior with recoverable strains up to 8-10%. This is in contrast to typical metals (e.g., steel) with 0.2% recoverable strain. The super-elastic behavior allows the shape memory alloy (SMA) fastener to experience large deformations under high engine imbalance conditions without failure, and allows the shape memory alloy (SMA) band to recover back to its original shape when the load (e.g., engine conditions) is released.

[0110] Variable stiffness: NiTi-based shape memory alloy (SMA) bands exhibit a unique variable stiffness, which, in combination with the super-elastic behavior, can be tuned to control the system response under different loads or engine operating conditions. That is, the extent of the fastening of the tubular structure is allowed to be controlled.

[0111] High energy dissipation: Shape memory alloy (SMA) exhibits high damping characteristics through hysteresis damping during the martensitic phase transformation, which can help control the vibrational response. NiTi shape memory alloy (SMA) bands can exhibit high hysteresis material damping up to 6%, which is higher than conventional metals (e.g., steel) bands.

[0112] Further, the shape memory alloy (SMA) band design can be used as an effective isolation system to control the pipe response under engine vibration and / or imbalance conditions as follows:

[0113] Normal engine vibration: At lower strains (less than 1%), the elastic modulus of the austenite phase of the shape memory alloy (SMA) band starts to come into play to take up normal engine operating conditions.

[0114] High engine vibration and imbalance loads: Under this engine condition, the shape memory alloy (SMA) band can be designed to deform to moderate to high strain levels (up to 8%). At this strain level, the shape memory alloy (SMA) band behaves as a super-elastic material with a plateau stress. There can be little or no change in the stress level as a function of strain, such that the pipe joint assembly can take up a wide range of deformations without much increase in the stress level. This low elastic modulus behavior of the shape memory alloy (SMA) band is used as an effective isolation system to insulate the tubular structure from high input vibrations or engine imbalance loads.

[0115] Extreme engine imbalance conditions such as blade shedding: The shape memory alloy (SMA) band can be designed for large strain (8% to 10%) development under extreme engine imbalance conditions. The increased elastic modulus and high strength martensite phase of the fastener can take up extreme imbalance conditions without failure and can recover back to the original shape of the shape memory alloy (SMA) band when the load is released.

[0116] The pipe spacing and fastening system of the present disclosure can include a variety of configured spacer elements, including recessed blocks, solid non-recessed blocks, thin-walled, cross-shaped configurations, or star-shaped configurations, that provide a wide flexibility in the number of pipes to be joined and adaptability in the design of the fastening elements to effectively support and spatially separate the individual pipes in the assembled bundle. In some examples, the spacer elements can be thick-walled solid blocks. Such blocks can include surface features on the contact surfaces to reduce the stress between thin-walled pipes and thick-walled spacer elements. In some examples, the spacer elements can be thin-walled.

[0117] The pipe spacing and fastening system of the present disclosure can provide an effective stress distribution at the pipe spacing and fastening system joint, provide a low stress field by contoured protrusions and / or dimples (also referred to as “beads” / “dimples”) on the recessed blocks, solid blocks, thin-walled, cross-shaped configurations, or star-shaped configurations spacer elements, provide a filleted joint, and thereby improve the reliability of each configuration of the pipe bundle assembly.

[0118] The tube spacing and fastening system of the present disclosure can provide a cost effective configuration that eliminates inspection and quality control issues associated with permanently linked tube bundle assemblies such as brazed or welded joints. The tube spacing and fastening system of the present disclosure increases "on-wing time" by reducing typical field issues associated with brazed or welded joints.

[0119] The tube spacing and fastening system of the present disclosure inherently provides adaptive spacing and compact tube bundle layout for optimal tube bundling, which saves a significant amount of space, cost, and weight. In one example, the fastening element can be replaced without having to account for the tubes.

[0120] Further aspects of the present disclosure are provided by the subject matter of the following clauses:

[0121] A system includes a spacer element configured to engage a plurality of tubular structures to spatially separate the plurality of tubular structures from one another and distribute stress among the plurality of tubular structures. A fastening element is configured to extend around at least a portion of an outer surface of the plurality of tubular structures and to fasten the plurality of tubular structures to the spacer element in an adaptively spaced configuration.

[0122] The system according to any preceding clause, wherein the adaptively spaced configuration includes a first length of the fastening element below a predetermined temperature range and a second length of the fastening element above the predetermined temperature range. The first length is different than the second length.

[0123] The system according to any preceding clause, wherein the adaptively spaced configuration includes a first configuration in which the plurality of tubular structures are movably spaced around the spacer element and a second configuration in which the plurality of tubular structures are immovably spaced around the spacer element.

[0124] The system according to any preceding clause, wherein the spacer element includes a first thin-walled bracket portion to engage a first tubular structure of the plurality of tubular structures and a second thin-walled bracket portion to engage a second tubular structure of the plurality of tubular structures. The first thin-walled bracket portion and the second thin-walled bracket portion are joined at a top end of the spacer element and at a bottom end of the spacer element.

[0125] The system according to any preceding clause, wherein the spacer element includes a first cradle bracket portion configured to engage a first tubular structure of the plurality of tubular structures, a second cradle bracket portion configured to engage a second tubular structure of the plurality of tubular structures, and a core portion separating the first cradle bracket portion and the second cradle bracket portion. The first cradle bracket portion, the second cradle bracket portion, and the core portion are joined at a top end of the spacer element and at a bottom end of the spacer element.

[0126] The system according to any preceding clause, wherein the first joint between the first cradle bracket portion and the top end, or the second joint between the second cradle bracket portion and the top end, or the third joint between the first cradle bracket portion and the bottom end, or the fourth joint between the second cradle bracket portion and the bottom end, or any combination thereof comprises a filleted joint.

[0127] The system according to any preceding clause, further comprising a first recess formed between the first cradle bracket portion and a first corresponding surface of the core portion, and a second recess formed between the second cradle bracket portion and a second corresponding surface of the core portion. The first recess is configured to accommodate a first portion of the fastening element, and the second recess is configured to accommodate a second portion of the fastening element.

[0128] The system according to any preceding clause, wherein a first tubular structure of the plurality of tubular structures is engaged with the first cradle bracket portion at a first contact surface, and a second tubular structure of the plurality of tubular structures is engaged with the second cradle bracket portion at a second contact surface. The first contact surface, or the second contact surface, or both the first and second contact surfaces comprise a plurality of surface features configured to distribute stress among the plurality of tubular structures.

[0129] The system according to any preceding clause, wherein the plurality of surface features comprises a plurality of protrusions, or dimples, or any combination thereof.

[0130] The system according to any preceding clause, wherein the spacer element comprises a core portion positioned at a center of the spacer element, and a plurality of radial arms arranged in a predetermined configuration, each radial arm being joined with the core portion at a respective base portion. At least one pair of adjacent radial arms and the core portion form a cradle bracket portion configured to engage a corresponding tubular structure in the cradle bracket portion.

[0131] The system according to any preceding clause, wherein the predetermined configuration comprises a cruciform configuration, or a star configuration, or any combination thereof.

[0132] The system according to any preceding clause, wherein the fastening element comprises a shape memory alloy (SMA) tape.

[0133] The system according to any preceding clause, wherein the shape memory alloy (SMA) tape comprises a nickel-titanium shape memory alloy.

[0134] A method includes providing a spacer element; joining a plurality of tubular structures to the spacer element; spatially separating the plurality of tubular structures from one another; and distributing stress among the plurality of tubular structures; extending a fastening element around at least a portion of an outer surface of the plurality of tubular structures; and fastening the plurality of tubular structures to the spacer element in an adaptively spaced configuration.

[0135] The method according to any preceding clause, wherein the fastening of the plurality of tubular structures to the spacer element in the adaptively spaced configuration includes fastening the plurality of tubular structures to the spacer element by a first length of the fastening element below a predetermined temperature range; and fastening the plurality of tubular structures to the spacer element by a second length of the fastening element above the predetermined temperature range. The first length is different than the second length.

[0136] The method according to any preceding clause, wherein the fastening of the plurality of tubular structures to the spacer element in the adaptively spaced configuration includes fastening the plurality of tubular structures to the spacer element in a first configuration in which the plurality of tubular structures are movably spaced about the spacer element and in a second configuration in which the plurality of tubular structures are immovably spaced about the spacer element.

[0137] The method according to any preceding clause, wherein the joining of the plurality of tubular structures to the spacer element includes joining a first tubular structure of the plurality of tubular structures to a first thin-walled bracket of the spacer element; joining a second tubular structure of the plurality of tubular structures to a second thin-walled bracket of the spacer element; and joining the first thin-walled bracket and the second thin-walled bracket at a top end of the spacer element and at a bottom end of the spacer element. The spatially separating of the plurality of tubular structures from one another includes spatially separating the first thin-walled bracket and the second thin-walled bracket by a hollow space between the first thin-walled bracket and the second thin-walled bracket.

[0138] The method of any preceding clause, wherein the joining of the plurality of tubular structures to the spacer element comprises: joining a first tubular structure of the plurality of tubular structures to a first cradle bracket of the spacer element; joining a second tubular structure of the plurality of tubular structures to a second cradle bracket of the spacer element; and joining the first cradle bracket, the second cradle bracket, and a core portion of the spacer element at a top end of the spacer element and at a bottom end of the spacer element. The spatially separating of the plurality of tubular structures comprises spatially separating the first cradle bracket and the second cradle bracket by the core portion positioned between the first cradle bracket and the second cradle bracket.

[0139] The method of any preceding clause, wherein the extending of the fastening element comprises rounding a first joint between the first cradle bracket and the top end, or a second joint between the second cradle bracket and the top end, or a third joint between the first cradle bracket and the bottom end, or a fourth joint between the second cradle bracket and the bottom end, or any combination thereof.

[0140] The method of any preceding clause, wherein the extending of the fastening element comprises: receiving a first portion of the fastening element in a first recess between the first cradle bracket and a first corresponding surface of the core portion; and receiving a second portion of the fastening element in a second recess between the second cradle bracket and a second corresponding surface of the core portion.

[0141] The method of any preceding clause, wherein the joining of each of the plurality of tubular structures to the spacer element comprises: joining a first tubular structure of the plurality of tubular structures and the first cradle bracket at a first contact surface; and joining a second tubular structure of the plurality of tubular structures and the second cradle bracket at a second contact surface. The distribution of stress in the plurality of tubular structures comprises providing a plurality of surface features on the first contact surface, or the second contact surface, or both the first contact surface and the second contact surface.

[0142] The method of any preceding clause, wherein the providing of the plurality of surface features comprises providing a plurality of protrusions, or dimples, or any combination thereof.

[0143] The method according to any preceding Clause, wherein the providing of the spacer element comprises: arranging a plurality of radial arms in a predetermined configuration; joining each radial arm at a respective base to a core portion of the spacer element; forming a cradle bracket portion and a core portion with at least one pair of adjacent radial arms; and joining a corresponding one of the plurality of tubular structures in the cradle bracket portion.

[0144] The method according to any preceding Clause, wherein the arranging of the plurality of radial arms in the predetermined configuration comprises arranging the plurality of radial arms in a cruciform configuration, or arranging the plurality of radial arms in a star configuration, or arranging the plurality of radial arms in any combination thereof.

[0145] The method according to any preceding Clause, wherein the extending of the fastening element comprises extending a shape memory alloy (SMA) tape.

[0146] The method according to any preceding Clause, wherein the shape memory alloy (SMA) tape comprises a nickel-titanium shape memory alloy.

[0147] While the foregoing description has been directed to preferred embodiments, it will be apparent to those skilled in the art that other variations and modifications can be made that will fall within the spirit or scope of the disclosure. Furthermore, features described with respect to one embodiment can be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A system for spacing and fastening tubular structures, comprising: a spacer element configured to engage a plurality of tubular structures to spatially separate the plurality of tubular structures from one another and distribute stress among the plurality of tubular structures, the spacer element comprising: a planar end; and at least two radially extending arms configured to engage a tubular structure of the plurality of tubular structures, the at least two radially extending arms each having a planar surface and a curved surface that engage the tubular structure; and a fastening element comprising a shape memory alloy (SMA) band and configured to be received in the planar end and extend around at least a portion of an outer surface of the plurality of tubular structures to fasten and compress the plurality of tubular structures to the spacer element in an adaptive spaced configuration.

2. The system of claim 1, wherein, the adaptive spaced configuration comprises a first length of the fastening element below a predetermined temperature range and a second length of the fastening element above the predetermined temperature range, the first length being different than the second length.

3. The system of claim 1, wherein, the adaptive spaced configuration comprises a first configuration in which the plurality of tubular structures are movably spaced around the spacer element and a second configuration in which the plurality of tubular structures are immovably spaced around the spacer element.

4. The system of claim 1, wherein, the shape memory alloy (SMA) band comprises a nickel-titanium shape memory alloy.

5. The system of claim 1, wherein, the spacer element comprises: (a) a core portion positioned at a center of the spacer element; and (b) the at least two radially extending arms arranged in a predetermined configuration, each radially extending arm being joined with the core portion at a respective base portion, the predetermined configuration comprising a cross-shaped configuration, or a star-shaped configuration, or any combination thereof, wherein at least one pair of adjacent radially extending arms and the core portion form a cradle bracket portion configured to engage a corresponding tubular structure in the cradle bracket portion.

6. The system of claim 1, wherein, the spacer element comprises: (a) a first thin-walled bracket portion for engaging a first tubular structure of the plurality of tubular structures; and (b) a second thin-walled bracket portion for engaging a second tubular structure of the plurality of tubular structures, wherein the first thin-walled bracket portion and the second thin-walled bracket portion are joined at a top end of the spacer element and at a bottom end of the spacer element.

7. The system of claim 1, wherein, the spacer element comprises: (a) a first cradle bracket portion configured to engage a first tubular structure of the plurality of tubular structures; (b) a second cradle bracket portion configured to engage a second tubular structure of the plurality of tubular structures; and (c) a core portion separating the first cradle bracket portion and the second cradle bracket portion, wherein the first cradle bracket portion, the second cradle bracket portion, and the core portion are joined at a top end of the spacer element and at a bottom end of the spacer element.

8. The system of claim 7, wherein, The first joint between the first cradle bracket portion and the top end, or the second joint between the second cradle bracket portion and the top end, or the third joint between the first cradle bracket portion and the bottom end, or the fourth joint between the second cradle bracket portion and the bottom end, or any combination thereof comprises a filleted joint.

9. The system of claim 7, further comprising: a first recess formed between the first cradle bracket portion and a first corresponding surface of the core portion, the first recess configured to accommodate a first portion of the fastening element; and a second recess formed between the second cradle bracket portion and a second corresponding surface of the core portion, the second recess configured to accommodate a second portion of the fastening element. A first tubular structure of the plurality of tubular structures is engaged with the first cradle bracket portion at a first contact surface, and a second tubular structure of the plurality of tubular structures is engaged with the second cradle bracket portion at a second contact surface, the first contact surface or the second contact surface, or both the first contact surface and the second contact surface, comprises a plurality of surface features configured to distribute stress among the plurality of tubular structures, and the plurality of surface features comprises a plurality of protrusions, or dimples, or any combination thereof.

10. The system of claim 7, wherein, 11. A method for spacing and fastening tubular structures, comprising: providing a spacer element having a plurality of cradle bracket portions each formed by a planar surface and a curved surface; engaging a plurality of tubular structures to the spacer element such that each tubular structure engages the planar surface and the curved surface of a respective cradle bracket portion, the spacer element spatially separating the plurality of tubular structures from one another and distributing stress among the plurality of tubular structures; extending a fastening element comprising a shape memory alloy (SMA) band around at least a portion of an outer surface of the plurality of tubular structures; and fastening and compressing the plurality of tubular structures to the spacer element in an adaptively spaced configuration. Fastening the plurality of tubular structures to the spacer element in the adaptively spaced configuration comprises fastening the plurality of tubular structures to the spacer element by a first length of the fastening element below a predetermined temperature range, and fastening the plurality of tubular structures to the spacer element by a second length of the fastening element above the predetermined temperature range, the first length being different than the second length.

12. The method of claim 11, wherein, Fastening the plurality of tubular structures to the spacer element in the adaptively spaced configuration comprises fastening the plurality of tubular structures to the spacer element in a first configuration in which the plurality of tubular structures are movably spaced about the spacer element, and a second configuration in which the plurality of tubular structures are immovably spaced about the spacer element.

13. The method of claim 11, wherein, The shape memory alloy (SMA) band comprises a nickel-titanium shape memory alloy.

14. The method of claim 11, wherein, ​ 15. The method of claim 11, wherein, Providing the spacer element includes arranging a plurality of radial arms in a predetermined configuration, joining each radial arm at a respective base portion to a core portion of the spacer element, forming a cradle bracket of the plurality of cradle brackets having at least one pair of adjacent radial arms and the core portion, and joining a corresponding one of the plurality of tubular structures in the cradle bracket, and the arranging of the plurality of radial arms in the predetermined configuration includes arranging the plurality of radial arms in a cross configuration, or arranging the plurality of radial arms in a star configuration, or arranging the plurality of radial arms in any combination thereof.

16. The method of claim 11, wherein, Joining the plurality of tubular structures to the spacer element includes joining a first tubular structure of the plurality of tubular structures to a first thin-walled bracket portion of the spacer element, joining a second tubular structure of the plurality of tubular structures to a second thin-walled bracket portion of the spacer element, and joining the first thin-walled bracket portion and the second thin-walled bracket portion at a top end of the spacer element and at a bottom end of the spacer element, and spatially separating the plurality of tubular structures from one another includes spatially separating the first thin-walled bracket portion and the second thin-walled bracket portion by a hollow space between the first thin-walled bracket portion and the second thin-walled bracket portion.

17. The method of claim 11, wherein, Joining the plurality of tubular structures to the spacer element includes joining a first tubular structure of the plurality of tubular structures to a first cradle bracket of the plurality of cradle brackets, joining a second tubular structure of the plurality of tubular structures to a second cradle bracket of the plurality of cradle brackets, and joining the first cradle bracket, the second cradle bracket, and a core portion of the spacer element at a top end of the spacer element and at a bottom end of the spacer element, and spatially separating the plurality of tubular structures from one another includes spatially separating the first cradle bracket and the second cradle bracket by the core portion positioned between the first cradle bracket and the second cradle bracket.

18. The method of claim 17, wherein, Extending the fastening element includes rounding a first joint between the first cradle bracket and the top end, or a second joint between the second cradle bracket and the top end, or a third joint between the first cradle bracket and the bottom end, or a fourth joint between the second cradle bracket and the bottom end, or any combination thereof.

19. The method of claim 17, wherein, Extending the fastening element includes receiving a first portion of the fastening element in a first recess between a first corresponding surface of the first cradle bracket and the core portion, and receiving a second portion of the fastening element in a second recess between a second corresponding surface of the second cradle bracket and the core portion.

20. The method of claim 19, wherein, Joining each of the plurality of tubular structures to the spacer element includes joining a first tubular structure of the plurality of tubular structures and the first cradle bracket at a first contact surface, joining a second tubular structure of the plurality of tubular structures and the second cradle bracket at a second contact surface, and distribution of stress in the plurality of tubular structures includes providing a plurality of surface features on the first contact surface or the second contact surface or both the first contact surface and the second contact surface, and the providing of the plurality of surface features includes providing a plurality of protrusions, or dimples, or any combination thereof.

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