Tubular structure

Abstract

Tubular structures (104), systems and methods generally relate to support structures having structural properties similar to thick-walled structures while being formed using materials having thicknesses suitable for rolling and welding and thus for rapid and cost-effective manufacturing. In particular, the tubular structure includes a tubular base (106) and a winding (108) supported on the base.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 966,803, filed on January 28, 2020, which is incorporated herein by reference in its entirety. Background Art

[0003] Many applications for large support structures have thick tubular walls. For example, offshore wind turbines require large thick-walled support towers and piles because such wind turbines are large in size and subject to high loads. The process for producing these support structures is expensive and time consuming, requiring the rolling and welding of thick steel plates (e.g., 30 mm-100 mm). Rolling plates of this thickness requires the use of expensive specialized equipment to generate large forces. Likewise, welding thick plates requires a large number of weld passes, making the process lengthy and thus increasing manufacturing costs.

[0004] Therefore, there is a need for forming support structures that are capable of withstanding high loads while being amenable to rapid and cost-effective manufacture. Summary of the invention

[0005] Tubular structures, systems, and methods generally relate to support structures having structural properties similar to thick-walled structures while being formed using materials having thicknesses suitable for rolling and welding and thus for rapid and cost-effective manufacturing.

[0006] According to one aspect, the tubular structure may include: a substrate having a first surface and a second surface opposite to each other, the first surface defining an elongated cavity, and the substrate having a tubular shape defining a longitudinal axis extending along the elongated cavity; and a winding supported on the second surface of the substrate, the winding comprising at least one layer, and each layer having a first longitudinal edge and a second longitudinal edge connected to each other along a corresponding spiral seam associated with a given layer and extending around the longitudinal axis of the substrate.

[0007] In some embodiments, the combined thickness of the wrap and the substrate may vary in a direction parallel to the longitudinal axis of the substrate. For example, the thickness of the wrap varies in a direction parallel to the longitudinal axis of the substrate. Additionally or alternatively, the thickness of the substrate is substantially constant in a direction parallel to the longitudinal axis of the substrate. Additionally or alternatively, the thickness of the wrap may vary monotonically in a direction parallel to the longitudinal axis of the substrate. As an example, the tubular shape of the substrate may include a frustum that tapers in a direction parallel to the longitudinal axis, and the thickness of the wrap decreases monotonically in the direction of the taper of the frustum.

[0008] In some embodiments, the at least one layer can be a plurality of layers, and the plurality of layers are at least partially stacked on each other in a radial direction. For example, each layer of the plurality of layers can surround the substrate at least once. Additionally or alternatively, the number of layers in the plurality of layers can vary in a direction parallel to the longitudinal axis of the substrate. Additionally or alternatively, each layer of the plurality of layers can be attached to the substrate, attached to at least one other layer of the plurality of layers, or a combination thereof. Additionally or alternatively, each layer of the plurality of layers can be welded to the substrate, another layer of the plurality of layers, or a combination thereof. In some cases, the corresponding spiral seam of a given layer can be longitudinally offset from the corresponding spiral seam of each layer adjacent to the given layer.

[0009] In some embodiments, the substrate may include a seam extending about a longitudinal axis of the substrate. For example, the corresponding spiral seam of the at least one layer of the wrap may be longitudinally spaced from the seam of the substrate along the longitudinal axis. Additionally or alternatively, the seam of the substrate may be parallel to the corresponding spiral seam of the at least one layer of the wrap.

[0010] According to another aspect, a system for forming a tubular structure may include: a drive system including a drive roller that is actuatable to move a planar form of stock material in a feeding direction; a bending device positioned to receive the planar form of stock material moving in the feeding direction, the bending device being controllable to bend the planar form of stock material to produce a curved form of stock material; a plurality of support rollers operable to rotatably support a curved surface of the material; and one or more pressure rollers positioned to receive the curved form of stock material from the bending device, and the one or more pressure rollers being movable to press the curved form of stock material from the bending device onto the curved surface of the material rotatably supported on the plurality of support rollers. In some embodiments, the system may further include a connector positioned to connect the curved form of stock material to itself, to the curved surface rotatably supported on the plurality of support rollers, or a combination thereof. Additionally or alternatively, the system may further include a guide system positioned to receive the stock material in a curved form from the bending device, the guide system including an actuator controllable to cause the stock material in a curved form to wrap along a corresponding spiral seam of a given layer of the tubular structure being formed. The actuator may include, for example, one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof. In some cases, the guide system may further include a sensor configured to sense a parameter indicative of a position of the stock material in a curved form along a corresponding spiral seam, wherein the actuator is in electrical communication with the sensor, and the actuator may be adjusted based on a signal from the sensor to adjust the position of the stock material in a curved form along the corresponding spiral seam of a given layer of the tubular structure being formed.

[0011] According to another aspect, a method of forming a tubular structure may include: bending a portion of a strip of planar form stock material into a curved form stock material; wrapping the curved form stock material onto a curved surface of a substrate to form a spiral seam around a longitudinal axis defined by the substrate; and connecting the curved form stock material at least to itself along the spiral seam.

[0012] In certain embodiments, wrapping the curved form of the stock material onto the curved surface of the substrate may include pressing the curved form of the stock material onto the curved surface of the substrate.

[0013] In some embodiments, joining the curved form of the stock material at least to itself along the spiral seam may include joining the curved form of the stock material to a curved surface of the substrate.

[0014] In certain embodiments, joining the curved form of the stock material at least to itself may include welding the curved form of the stock material to itself along the spiral seam.

[0015] According to another aspect, a system for forming a tubular structure may include: a tensioning roller positioned to contact a planar-form stock material as the planar-form stock material moves in a feed direction; a rotator actuable to rotate a curved surface of a substrate about a longitudinal axis defined by the substrate; a guiding system including an actuator controllable to wrap the planar-form stock material along a spiral seam about the longitudinal axis of the substrate; and a connector positioned to connect the stock material at least to itself along the spiral seam as the tubular structure is being formed.

[0016] In some embodiments, the actuator may include one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof.

[0017] In certain embodiments, the guidance system may further include a sensor configured to sense a parameter indicative of a position of the inventory material along the spiral seam, wherein the actuator is electrically connected to the sensor and the actuator may be adjusted based on a signal from the sensor to adjust the position of the inventory material in planar form along the spiral seam as the tubular structure is being formed.

[0018] According to yet another aspect, a method of forming a tubular structure may include: coupling a plurality of sheets in a nonlinear end-to-end engagement with one another to form a planar form of stock material; securing the stock material to a curved surface of a substrate defining a longitudinal axis; and rotating the curved surface of the substrate about the longitudinal axis of the substrate while the stock material is secured to the substrate, the rotation of the curved surface of the substrate causing the planar form of the stock material to bend about the curved surface of the substrate, wherein a first longitudinal edge and a second longitudinal edge of the stock material form at least one spiral seam about the longitudinal axis of the substrate. In some embodiments, the method may further include moving the planar form of the stock material through one or more tensioning rollers while the stock material is secured to the substrate and the curved surface of the substrate is rotated about the longitudinal axis. Additionally or alternatively, the method may further include joining the stock material to itself at least along the at least one spiral seam. In some cases, joining the stock material to itself at least along the at least one spiral seam may further include joining a layer of the stock material to the curved surface of the substrate, to a previous layer of stock material, or a combination thereof.

[0019] According to another aspect, the tubular structure may include a first shell, a second shell having a truncated cone shape, and a stabilizing member, wherein the first shell is nested in the second shell and the first shell and the second shell define a gap therebetween, the stabilizing member being disposed in the gap and maintaining the positions of the first shell and the second shell relative to each other.

[0020] In some embodiments, the first shell can be substantially parallel to the second shell along a longitudinal axis defined by the first shell.

[0021] In certain embodiments, the stabilizer may include a filler material bonded to the first shell, the second shell, or a combination thereof.

[0022] In some embodiments, the stabilizer may include a plurality of structural elements extending through the gap and coupled to each of the first shell and the second shell. For example, the first shell may define a plurality of first holes, the second shell may define a plurality of second holes aligned with the plurality of first holes, and each of the plurality of structural elements may extend through one of the plurality of first holes and a corresponding one of the plurality of second holes.

[0023] According to another aspect, the tubular structure may include: a shell having a first surface and a second surface, the first surface defining an elongated cavity, the first surface being opposite to the second surface, the shell having a tubular shape defining a longitudinal axis extending along the elongated cavity, and the shell having a spiral seam extending around the longitudinal axis; and a plurality of elongated ribs connected to the shell, wherein a longitudinal dimension of each elongated rib is substantially parallel to the longitudinal axis defined by the tubular shape of the shell.

[0024] In some embodiments, the tubular shape of the housing may be frusto-conical.

[0025] In certain embodiments, at least one of the plurality of elongated ribs may be secured along the first surface of the housing.

[0026] In some embodiments, at least one of the plurality of elongated ribs may be secured along the second surface of the housing.

[0027] In certain embodiments, the plurality of elongated ribs may be coupled to one another along a plurality of longitudinal seams that are substantially coplanar with a longitudinal axis defined by the tubular shape of the housing.

[0028] In some embodiments, each of the plurality of elongated ribs may be V-shaped having a first leg and a second leg coupled to each other at an apex, and the first leg and the second leg are coupled to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1A is a perspective view of a wind turbine assembly including a tubular structure.

[0030] Figure 1B yes Figure 1A Side view of the tubular structure.

[0031] Figure 1C yes Figure 1A A cross-sectional side view of a tubular structure, wherein the cross section is along Figure 1B Intercepted by line 1C-1C in.

[0032] Figure 1D It is along Figure 1C A magnified view of the tubular structure in the area of ​​detail 1D.

[0033] Figure 2A is a block diagram of a manufacturing system for forming a tubular structure.

[0034] Figure 2B Is Figure 2A Schematic representation of the winding process performed by the manufacturing system.

[0035] Figure 3 is a flow chart of an exemplary method of forming a tubular structure.

[0036] Figure 4A is a block diagram of a manufacturing system for forming a tubular structure.

[0037] Figure 4B Is Figure 4A Schematic representation of the winding process performed by the manufacturing system.

[0038] Figure 5 is a flow chart of an exemplary method of forming a tubular structure.

[0039] Fig. 6A is a perspective view of the tubular structure (i.e., the first shell, the second shell and the filler therebetween).

[0040] Figure 6B yes Fig. 6A A perspective view of a tubular structure shown with a section of the tubular structure removed.

[0041] Fig. 7A is a perspective view of a tubular structure including a first shell, a second shell, and a plurality of structural elements extending therebetween.

[0042] Figure 7B yes Fig. 7A Side view of the tubular structure.

[0043] Figure 7C is a top view of a cross section of a tubular structure, wherein the cross section is along Figure 7B Intercepted along line 7B-7B in FIG.

[0044] Fig. 8Ais a perspective view of a tubular structure including a shell and a plurality of elongated ribs coupled to the shell.

[0045] Figure 8B yes Fig. 8A Top view of the tubular structure.

[0046] Figure 8C yes Fig. 8A A perspective view of the elongated ribs of a tubular structure.

[0047] Like reference numbers in the various drawings indicate like elements. DETAILED DESCRIPTION

[0048] Hereinafter, embodiments will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown.The foregoing, however, may be implemented in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

[0049] All documents mentioned herein are incorporated herein by reference in their entirety. Unless otherwise expressly stated or apparent in the text, reference to an item in the singular should be understood to include the plural items and vice versa. Unless otherwise stated or apparent from the context, grammatical conjunctions are intended to express any and all disjunctive conjunctions and conjunction combinations of conjunction clauses, sentences, words, etc. Thus, the term "or" should generally be understood to mean "and / or", and the term "and" should generally be understood to mean "and / or".

[0050] Unless otherwise indicated herein, the description of the range of values ​​herein is not intended to be limiting, but refers individually to any and all values ​​falling within the range, and each individual value within such a range is incorporated into the specification as if it is individually described herein. When attached with a numerical value, the words "approximately", "approximately", etc. should be interpreted as including any deviation as will be understood by those of ordinary skill in the art, to operate satisfactorily for the intended purpose. The range of values ​​and / or numerical values ​​is provided herein only as an example, and does not constitute a limitation on the scope of the described embodiments. The use of any and all examples or exemplary language ("for example", "such as", etc.) is only intended to better illustrate the embodiments, and does not constitute a limitation on the scope of these embodiments. The statements in the specification should not be interpreted as indicating that any unclaimed element is essential for practicing the disclosed embodiments.

[0051] As used herein, the term "tubular structure" should be understood to include any form and shape of a structure that defines an elongated cavity and has a substantially curvilinear two-dimensional profile about a longitudinal axis extending along the elongated cavity. Thus, unless otherwise specified or apparent from the context, some examples of tubular structures include frustums and cylinders (e.g., right cylinders). Unless otherwise indicated, it will be understood that the tubular shapes described herein may include geometrically approximated ideal shapes, such as curves, truncated cones, cones, or cylinders. Such approximations of geometric ideals may include deviations from geometric ideals caused by frustum approximations using stacked material layers and / or typical manufacturing tolerances.

[0052] Furthermore, as used herein, the term "thickness" and variations thereof should be understood to refer generally to the wall thickness of a given material and should be understood in conjunction with the context. For example, unless otherwise specified or apparent from the context, with respect to a single layer, thickness will be understood generally to refer to the thickness of a single layer. Additionally or alternatively, unless indicated to the contrary, with respect to multiple layers, thickness will be understood to refer to the total thickness of the multiple layers wound on top of each other. Further or alternatively, with respect to the tubular structures described herein, thickness will be understood to refer to the total thickness of the tubular structure at a given point along the longitudinal axis, and thus may refer to the wall thickness of the substrate alone or the combined thickness of the substrate supporting the winding, as may be the case at a given point along the longitudinal axis.

[0053] Further, unless the contrary intention is apparent from the context, as used herein, the terms "longitudinal" and "radial" should be understood to refer to directions in a cylindrical coordinate system. Thus, in particular, reference to a radial direction will be understood to refer to a direction perpendicular to the longitudinal axis. Additionally or alternatively, a longitudinal direction associated with such a cylindrical coordinate system will be understood to be parallel to the longitudinal axis associated with the structure being described. While the longitudinal axis may correspond to the central axis of any given structure, it will be appreciated that this is not necessarily the case in certain embodiments.

[0054] The apparatus, system and method of the present disclosure are described in the context of a tubular structure, which is used as a tower for a large wind turbine (e.g., an offshore wind turbine) capable of withstanding large loads. More specifically, for clarity and efficiency of description, various aspects of the present disclosure are generally described in the context of a truncated cone, but should be understood to be equally applicable to a cylinder, unless the contrary intention is indicated. In addition, for clarity of description, the tubular structure is shown as an integral structure. However, unless the contrary intention is indicated, any one or more of the various different truncated cones described herein should be understood to be manufactured in sections according to the dimensional requirements of a given end use. Further, unless otherwise specified or obvious from the context, such tubular structures described herein can be used for any one or more of a variety of different applications requiring high strength and / or high rigidity, such as tubular structures in piles or other support structures for wind turbines, or more generally for tubular structures of large civil structures, pipelines, pressure vessels, etc.

[0055] Reference now Figure 1A-Figure 1D , the wind turbine assembly 100 may include a wind turbine 102 and a tubular structure 104. The wind turbine 102 may be supported by the tubular structure 104, wherein the tubular structure 104 is subjected to load conditions associated with the movement of the wind turbine 102 and the installation environment. In some cases, the tubular structure 104 may have a diameter that decreases along the length of the tubular structure 104, so that the top has a smaller diameter than the bottom when the wind turbine 102 is attached, wherein the tubular structure 104 is securely fixed to the ground or other rigid surface. The longitudinally tapered diameter of the tubular structure 104 can be useful, for example, to resolve competing considerations in efficiently using materials while providing structural strength to support loads imposed on the tubular structure 104 in the field. However, the strength distribution that can be achieved using longitudinal tapering may be subject to certain limitations (e.g., dimensional constraints associated with transportation and / or installation). Thus, as described in more detail below, the material thickness of the tubular structure 104 may additionally or alternatively be varied to help achieve a predetermined strength profile of the tubular structure 104 while taking into account practical considerations such as installation time and cost.

[0056] The tubular structure 104 may include a base 106 and a wrap 108. The base 106 may have a first surface 110 and a second surface 112 opposite to each other, with a distance between the first surface 110 and the second surface 112 defining a thickness of the base 106. The first surface 110 of the base 106 may define an elongated cavity 114, and the base 106 may have a tubular shape defining a longitudinal axis "L" extending along the elongated cavity 114. The wrap 108 may include a plurality of layers 116a, b, c, d (collectively referred to as a plurality of layers 116a, b, c, d and individually referred to as a first layer 116a, a second layer 116b, a third layer 116c, and a fourth layer 116d) and the wrap 108 may be supported on the second surface 112 of the base 106. That is, as described in more detail below, the first layer 116a may be supported on the second surface 112 of the substrate 106, the second layer 116b may be supported on the first layer 116a, the third layer 116c may be supported on the second layer 116b, and the fourth layer 116d may be supported on the third layer 116c. Although the tubular structure 104 is described as including a plurality of layers 116a, b, c, d, it will be appreciated that this is for the purpose of clarity and efficiency in describing certain aspects associated with the winding 108 including a plurality of layers. However, unless otherwise specified, any description associated with the plurality of layers 116a, b, c, d hereinafter will be understood to apply to embodiments including only a single layer of one layer and / or embodiments including more than four layers. Additionally or alternatively, for the purpose of clarity and efficiency in describing, each of the plurality of layers 116a, b, c, d will be understood to have the same nominal composition as one another and may have any one or more of varying different nominal thicknesses relative to one another, which may help achieve a given thickness profile of the tubular structure 104 in a direction parallel to the longitudinal axis "L".

[0057] With the wrap 108 supported on the substrate 106, the tubular structure 104 may have strength similar to an otherwise dimensionally identical structure formed using a thick-walled material having a material thickness that is the same as the combined material thickness of the plurality of layers 116a, b, c, d and the substrate 106. However, the wrap 108 supported on the substrate 106 has significant advantages over achieving a target thickness distribution (e.g., strength distribution) in the longitudinal direction using a thick-walled material. For example, because each of the plurality of layers 116a, b, c, d is individually thinner than a thick-walled material, each of the plurality of layers 116a, b, c, d may be rolled, welded, or otherwise manipulated relatively easily compared to a thick-walled material. That is, achieving a target overall thickness using the wrap 108 positioned on the substrate 106 may reduce production time and / or production costs compared to achieving a target overall thickness using a thick-walled material. Similarly, each of the plurality of layers 116a,b,c,d may be sized to reduce or eliminate the need for specialized equipment that would otherwise be required to accommodate thick-walled materials having a thickness comparable to the plurality of layers 116a,b,c,d.

[0058] In general, the base 106 may be any one or more of a variety of different tubular shapes for supporting the plurality of layers 116a, b, c, d such that the combined tubular structure 104 may have a predetermined thickness profile in a direction parallel to the longitudinal axis "L". For example, the base 106 may include a frustum of a cone, which itself has a strength profile that efficiently utilizes material to support the wind turbine 102, and the wrap 108 may be positioned about the frustum of the cone to reinforce the wider end of the frustum, thereby enhancing the strength difference achievable between the wide end of the frustum of a given size and the narrow end of the frustum of the cone. In other words, the wrap 108 supported on the base 106 may advantageously decouple certain design constraints (e.g., strength versus size) associated with using only a single layer of material to form a support structure.

[0059] In certain embodiments, the substrate 106 may have a substantially constant thickness in a direction parallel to the longitudinal axis "L" (e.g., to allow for normal manufacturing tolerances associated with commercially available metal sheet stock). Such a substantially constant thickness may be useful, for example, for forming the substrate 106 using any one or more of a variety of different stock materials that may be easily and cost-effectively procured. Additionally or alternatively, forming the substrate 106 with a constant thickness may be useful, for example, for quickly forming the substrate 106 using any one or more of a variety of different techniques and with little or no need for specialized equipment.

[0060] In general, the plurality of layers 116a, b, c, d of the wrap 108 may be sized relative to each other and relative to the substrate 106 to achieve a predetermined thickness profile of the tubular structure 104 in a direction parallel to the longitudinal axis "L". Notably, one or more of the plurality of layers 116a, b, c, d may extend along only a portion of the longitudinal dimension of the substrate 106 such that the thickness of the wrap 108 in a radial direction varies in a direction parallel to the longitudinal axis "L" to help vary the thickness profile of the tubular structure 104 in a direction parallel to the longitudinal axis "L". For example, the number of the plurality of layers 116a, b, c, d may decrease in a direction parallel to the longitudinal axis "L" such that the wrap 108 has a monotonically decreasing thickness in a direction parallel to the longitudinal axis "L". That is, according to such an example, the tubular structure 104 may have a first total thickness t along the first end portion 117 of 1 and a second total thickness t along the second end portion 119 2 , where the first total thickness t 1 Greater than the second total thickness t 2 . While one or more of the plurality of layers 116a,b,c,d may have a constant wall thickness in a direction parallel to the axis “L”, it will be appreciated that one or more of the plurality of layers 116a,b,c,d may have a wall thickness that varies along at least a portion of the longitudinal dimension of a given layer. Additionally or alternatively, while each of the plurality of layers 116a,b,c,d may have the same thickness profile as another, it will be appreciated that one or more of the plurality of layers 116a,b,c,d may have a thickness profile that is different than at least another of the plurality of layers 116a,b,c,d. Thus, more generally, unless otherwise specified or apparent from the context, the plurality of layers 116a,b,c,d may have any one or more of a variety of different thickness profiles in a direction parallel to the longitudinal axis “L” as may be necessary or useful to achieve an overall thickness profile of the wrap 108 in a direction parallel to the longitudinal axis “L”.

[0061] exist Figure 1C In the specific example shown in FIG. 1 , the plurality of layers 116a, b, c, d of the winding 108 are supported on the substrate 106 in a winding configuration in which the plurality of layers 116a, b, c, d of the winding are at least partially stacked on top of each other in a radial direction, resulting in a thickness profile of the tubular structure 104 having five different thicknesses in a direction parallel to the longitudinal axis “L”. The first thickness t along the first end portion 117 of the tubular structure 104 is 1 The second thickness t along the second end portion 119 of the tubular structure 104 corresponds to the combined thickness of the substrate 106 and all of the plurality of layers 116a, b, c, d. 2corresponds to the wall thickness between the first surface 110 and the second surface 112 of the base body 106 .

[0062] Each of the plurality of layers 116a, b, c, d may have a first longitudinal edge 113 and a second longitudinal edge 115 coupled to one another such that each of the plurality of layers 116a, b, c, d wraps around the base 106 at least once. For example, the first longitudinal edge 113 and the second longitudinal edge 115 of each of the plurality of layers 116a, b, c, d may be coupled to one another along a respective plurality of spiral seams 118a, b, c, d (collectively referred to as a plurality of spiral seams 118a, b, c, d and individually referred to as a first spiral seam 118a, a second spiral seam 118b, a third spiral seam 118c, and a fourth spiral seam 118d). That is, the first layer 116a may form a first spiral seam 118a, the second layer 116b may form a second spiral seam 118b, the third layer 116c may form a third spiral seam 118c, and the fourth layer 116d may form a fourth spiral seam 118d. Each of the multiple spiral seams 118a, b, c, d can extend around the longitudinal axis "L" of the base 106, such as can be used to form each of the multiple spiral seams 118a, b, c, d in a continuous or substantially continuous joining process as the base 106 rotates around the longitudinal axis "L" according to any one or more of the various different techniques described herein.

[0063] In certain embodiments, the plurality of layers 116a,b,c,d may be joined to the substrate 106 and / or to each other, such as to effectively distribute external loads through the tubular structure 104. For example, the plurality of layers 116a,b,c,d may be joined to the substrate 106 and / or to each other using a plurality of welds 120a,b,c,d,e (collectively referred to as a plurality of welds 120a,b,c,d and individually referred to herein as a first weld 120a, a second weld 120b, a third weld 120c, a fourth weld 120d, and a fifth weld 120e). As used in this context, the term "weld" should be understood to refer to a joint formed between at least two adjacent pieces of material.

[0064] For example, the first weld 120a may be a double-sided weld for joining the substrate 106 to itself along the seam 122, such that the substrate 106 may be a stable structure upon which the plurality of layers 116a, b, c, d of the wrap 108 may be positioned and to which the plurality of layers 116a, b, c, d may be directly or indirectly secured to form the tubular structure 104. In some cases, the seam 122 of the substrate 106 may be a spiral seam, such as may be used to generate the substrate 106 using any one or more of a variety of different automated techniques, such as described in U.S. Pat. No. 9,302,303, issued to Smith et al. on April 5, 2016, and entitled “TAPERED STRUCTURE CONSTRUCTION,” the entire contents of which are incorporated herein by reference. Additionally or alternatively, the first weld 120a may be formed as part of a process different from the process used to secure the plurality of layers 116a, b, c, d to the substrate 106. Thus, while the first weld 120a may correspond to a spiral seam of the substrate 106, it will be appreciated that such a spiral seam may not necessarily be used on the substrate 106, given that the substrate 106 may not be formed as part of a continuous or substantially continuous process in which a spiral seam is useful. Additionally or alternatively, the second weld 120b may penetrate into the substrate 106 and into the first spiral seam 118a formed by the first longitudinal edge 113 and the second longitudinal edge 115 of the first layer 116a, such that the second weld 120b may be substantially coextensive with the first spiral seam 118a. Similarly, the third weld 120c may be coextensive along the second spiral seam 118b to join the first layer 116a and the second layer 116b to each other. In a similar manner, the second layer 116b, the third layer 116c, and the fourth layer 116d may be joined to each other via the fourth weld 120d and the fifth weld 120e.

[0065] The first longitudinal edge 113 and the second longitudinal edge 115 of each of the plurality of layers 116a, b, c, d may each include one or more features for facilitating alignment and / or coupling of the edges relative to each other. For example, the first longitudinal edge 113 and the second longitudinal edge 115 may each include a single bevel, such that when aligned, the first longitudinal edge 113 and the second longitudinal edge 115 of a given layer form a "V" shape, wherein a respective one of the second weld 120b, the third weld 120c, the fourth weld 120d, or the fifth weld 120e may be formed into the "V" shape by using a single-sided welding process. In the first layer 116a, such a "V" shaped edge preparation may, for example, facilitate simultaneous joining of the first longitudinal edge 113 and the second longitudinal edge 115 to each other and to the substrate 106, thereby resulting in better weld quality. Similarly, for each of the subsequent layers (second layer 116b, third layer 116c, and fourth layer 116d), the "V" shaped edge preparation can help to simultaneously join the first longitudinal edge 113 and the second longitudinal edge 115 to each other and to the previous layer with a corresponding improvement in welding quality.

[0066] In some cases, the plurality of spiral seams 118a, b, c, d may be longitudinally offset from one another in a direction parallel to the longitudinal axis "L" of the substrate 106. With such an offset, the plurality of seams 118a, b, c, d are not aligned on top of one another in a radial direction extending from the longitudinal axis "L". This type of spacing may help distribute stresses caused by welding along the tubular structure 104 as it is formed, thereby helping to control the quality of the tubular structure 104.

[0067] Reference now Figure 2A and Figure 2B , the system 230 may include one or more instances of a pressure roller 238, a drive system 232, a bending device 234, and a plurality of support rollers 236. Unless otherwise specified or apparent from the context, the system 230 may be operable to form the tubular structure 104 ( Figure 1A-Figure 1D ). For example, the drive system 232 can be actuatable to move a planar form of stock material 239 (e.g., from a stock source 240) in a feed direction "F" and into the bending device 234, where the planar form of stock material 239 can be pre-bent into a curved form of stock material 239. The curved form of stock material 239 can be moved between one or more instances of the pressure roller 238 and a curved surface 241 of the material supported on the plurality of support rollers 236, thereby ultimately forming the tubular structure 104 ( Figure 1A-Figure 1D ) of winding 108 ( Figure 1A-Figure 1D That is, the tubular structure 104 ( Figure 1A-Figure 1D), the curved surface 241 receiving the curved form of the stock material 239 may be the second surface 112 ( Figure 1A-Figure 1D ) or the surface of the previous layer of the winding 108 ( Figure 1A-Figure 1D Pre-rolling the stock material 239 in the bending device 234 to form the stock material 239 in a curved form may increase the conformity of the stock material 239 to the curved surface 241 (eg, conformity to the curved surface 241). Figure 1A-Figure 1D The degree of the matrix 106 and / or the previous layer of the plurality of layers 116a, b, c, d) in order to increase the tubular structure being formed (e.g., Figure 1A-Figure 1D The strength, rigidity and / or other desired properties of the tubular structure 104).

[0068] In general, the drive system 232 can include a drive roller 233 that can be actuatable to cause the planar form of the stock material 239 to move in a feed direction "F". For example, the drive roller 233 can clamp the planar form of the stock material so that rotation of the drive roller 233 can cause the planar form of the stock material 239 to move along the feed direction "F". In some embodiments, the feed direction "F" can be substantially constant (e.g., the drive roller 233 is in a substantially stationary position as the rotation of the drive roller 233 causes the planar form of the stock material 239 to move to and / or through the bending device 234). Additionally or alternatively, the feed direction "F" can vary so that the planar form of the stock material 239 undergoes rotational motion and / or substantially rotational motion as the planar form of the stock material 239 moves to and through the bending device 234. Such a variation in the feed direction "F" can be used to align the edges of the stock material 239 to form any one or more of the spiral seams described herein. Examples of such changes in feed direction "F" that produce rotational and / or substantially rotational motion as part of the manufacturing process of the tubular structure are described in U.S. Pat. Nos. 9,302,303, entitled "TAPERED STRUCTURE CONSTRUCTION," issued to Smith et al. on April 5, 2016, and 10,189,064, entitled "CONTROL SYSTEM AND METHOD FOR TAPERED STRUCTURE CONSTRUCTION," issued to Takata et al. on January 29, 2019, each of which is incorporated herein by reference in its entirety. More generally, any device suitable for moving planar materials according to any of a variety of different techniques known in the art can be used to move planar form stock material 239 from a stock source 240 to, and in some cases, through, the bending device 234. For example, such a device can include a robotic arm, a piston, a servomotor, a screw, an actuator, a roller, a drive, an electromagnet, or a combination thereof.

[0069] The bending device 234 may be positioned to receive the planar form of the stock material 239 moving in the feed direction “F”, and the bending device 234 may bend the planar form of the stock material 239 fed therein to produce the curved form of the stock material 239. As an example, the bending device 234 may bend the planar form of the stock material 239 without imparting an in-plane deformation to the stock material 239. Additionally or alternatively, the bending device 234 may impart a controlled amount of curvature to the stock material 239 such that the stock material 239 in the curved form may approximately match the curvature of the curved surface 241 onto which the curved form of the stock material 239 is moved.

[0070] The bending device 234 may, for example, include roller sets 242a, 242b, 242c positioned relative to each other and relative to the planar form of the stock material 239 so as to impart curvature to the planar form of the stock material 239 fed through the roller sets 242a, 242b, 242c. In some cases, the roller sets 242a, 242b, 242c may be arranged as a triple roller, and further or alternatively, the roller sets 242a, 242b, 242c may be movable relative to each other to vary the bending moment applied to the stock material 239 moving through the bending device 234. Each of the roller sets 242a, 242b, 242c may, for example, include a plurality of individual rollers that may be independently rotatable relative to each other and arranged along a respective axis defined by a respective one of the roller sets 242a, 242b, 242c. Additionally or alternatively, individual rollers in the roller sets 242a, 242b, 242c may be positioned relative to respective axes defined by the one of the roller sets 242a, 242b, 242c (eg, via an actuation signal received by a control system).

[0071] Generally speaking, the support rollers 236 can allow the curved surface 241 of the tubular structure being formed to rotate relative to the curved form stock material 239 that is moved from the bending device 234 onto the curved surface 241. In some embodiments, one or more of the support rollers 236 can be actively controlled to cause the curved surface 241 to rotate at a predetermined rate, such as can be used to provide tension to the curved form stock material 239 to help position the curved form stock material 239 tightly onto the curved surface 241. In some cases, one or more of the support rollers 236 can be passive, so that as the tubular structure is being formed, the force applied to the curved surface 241 by the moving curved form stock material 239 can cause the curved surface 241 to rotate.

[0072] Each of the one or more instances of the pressure roller 238 may include one or more rollers that are movable to press the stock material 239 in a curved form onto a curved surface 241 that is rotatably supported on the plurality of support rollers 236. For example, at least one instance of the pressure roller 238 may rotate about an axis parallel to the curved surface 241 of the substrate 106 to move the stock material 239 in a curved form from the bending device 234 onto the curved surface 241. Additionally or alternatively, at least one instance of the pressure roller 238 may move in a radial direction relative to the tubular structure being formed, wherein such radial movement of the at least one instance of the pressure roller 238 is used to control the degree of conformity between the stock material 239 in a curved form and the curved surface 241. In other words, the radial movement of the at least one instance of the pressure roller 238 may reduce the likelihood of unintended gaps between material layers of the winding and / or between the winding and the substrate, wherein reducing the likelihood of such gaps includes improving load-bearing performance.

[0073] In some embodiments, the system 230 may include a connector 244 that is positioned or positionable (e.g., along the Figure 1A-Figure 1D In some embodiments, the connector 244 may be positioned or positionable to connect the stock material 239 in the curved form to the curved surface 241 rotatably supported on the plurality of support rollers 236. As an example, the connector 244 may be positioned between two instances of the pressure roller 238 to increase the possibility of a tight fit between the stock material 239 in the curved form and the curved surface 241 when performing the connecting operation. In some cases, as the stock material 239 in the curved form moves onto the curved surface 241 rotating on the support roller 236, the connector 244 may continuously mechanically connect the materials together. This continuous mechanical connection may be used to achieve, in particular, the target structural properties of the tubular structure being formed. In addition or alternatively, the connector 244 may be operable to intermittently connect (e.g., at a fixed distance) the material along any one or more of the various different spiral joints described herein, wherein this intermittent connection is used for faster throughput.

[0074] The connector 244 may, for example, include a welder that is operable to form any one or more of the various welds described herein. Various techniques for welding are known in the art and may be suitable for joining any one or more edges together as contemplated herein. This may include, for example, any welding technique that melts any one or more of the base metal or other materials along the various seams described herein (optionally together with fillers added to the joint to improve the strength of the joint). Conventional welding techniques suitable for structurally joining metals may include, for example, but are not limited to, gas shielded metal arc welding (GMAW), submerged arc welding (SAW), laser welding, and gas shielded tungsten arc welding (also referred to as tungsten, inert gas, or "TIG" welding) including inert gas (MIG) and / or metal active gas (MAG), and the like.

[0075] In certain embodiments, the system 230 may include a guide system 245 positioned to receive the stock material 239 in a curved form from the bending device 234. The guide system 245 may, for example, include an actuator 246 that may be controlled (e.g., in a direction substantially parallel to the longitudinal axis of the tubular structure being formed) to wind the stock material 239 in a curved form along a corresponding spiral seam of a given layer of a winding coupled to a substrate of the tubular structure being formed. Some examples of the actuator 246 include, but are not limited to, one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof. In some cases, the guide system 245 may further include a sensor 247 that is operable to sense a parameter indicating a position of the stock material 239 in a curved form along a spiral seam formed by moving the stock material 239 in a curved form onto the bending surface 241. Examples of the sensor 247 may include an optical sensor, one or more cameras of a machine vision system, a contact sensor, or a combination thereof. Actuator 246 may be adjustable, for example, based on a signal from sensor 247 to effect a corresponding adjustment in the position of curved form stock material 239 along a spiral seam formed as curved form stock material 239 moves onto curved surface 241 .

[0076] Although one or more aspects of the operation of the system 230 may be performed by an operator through manual operation, in some embodiments, the system 230 may include a control system 248 to facilitate accurate and repeatable control of certain aspects of the operation of the system 230. The control system 248 may, for example, include a processing unit 249 and a storage medium 250 in communication with the processing unit 249. The processing unit 249 may include one or more processors, and the storage medium 250 may include a non-transitory computer-readable storage medium. The storage medium 250 may store computer-executable instructions that, when executed by the processing unit 249, cause the system 230 to perform one or more of the various different aspects of manufacturing a tubular structure using the system 230. Optionally, the control system 248 may include an input device (e.g., a keyboard, a mouse, and / or a graphical user interface) in communication with the processing unit 249 and the storage medium 250, so that as the processing unit 249 performs one or more of the manufacturing methods described herein, the processing unit 249 additionally or alternatively responds to input received through the input device.

[0077] Figure 3 352 is a flow chart of an exemplary method 352 for forming a tubular structure. Unless otherwise specified or apparent from the context, any one or more aspects of the exemplary method 352 may be implemented as computer-readable instructions stored on the storage medium 250 ( Figure 2A ) and can be controlled by the control system 248 ( Figure 2A ) processing unit 249 ( Figure 2A ) executes the operating system 230 ( Figure 2A ) to form a reference Figure 1A-Figure 1D In certain embodiments, the exemplary method 352 may include certain manufacturing steps, which may include joining a plurality of sheets to each other in a non-linear end-to-end joint to produce a stock material in a planar form having straight longitudinal edges, which may be wound to form a spiral seam. Additionally or alternatively, at the beginning of the process of winding a given layer, the exemplary method 352 may include securing the stock material to a curved surface of a substrate or a previous layer, as the case may be. For the sake of clarity and efficiency of explanation, these manufacturing steps may be related to Figure 5 The discussion of is described in more detail below, assuming that Figure 5 The method presented in Figure 4A and Figure 4B The hardware diagrams in the figure make it easier to understand these steps. However, unless otherwise specified or obvious from the context, the Figure 5 Any one or more of the preparation steps described below will be understood to be included in exemplary method 352 without departing from the scope of the present disclosure.

[0078] As shown in step 354, the exemplary method 352 may include bending a portion of the planar form of the stock material strip into a curved form of the stock material. Such bending may be performed, for example, by moving the planar form of the stock material to and passing through a bending device (such as the bending device 234 ( Figure 2A and Figure 2B By such bending, the stock material can approximate the curvature of the curved surface onto which the stock material can be directed. For example, where the tubular structure being formed is a frustum of a cone, a strip of stock material in planar form can be bent to gradually change diameter in accordance with a corresponding change in diameter of the frustum of the tubular structure being formed. In such a case, it will be appreciated that while the multiple layers wound on the frustum of a cone substrate may differ from a geometric frustum, the final shape of the tubular structure having these features is referred to herein as a frustum.

[0079] As shown in step 356, exemplary method 352 may include wrapping the stock material in a curved form onto a substrate (e.g., Figure 1B and Figure 1C The stock material in a curved form may be wound onto a curved surface of a substrate (106) to form a spiral seam about a longitudinal axis defined by the substrate. The substrate may be formed separately (e.g., by a can rolling or spiral welding process), and may additionally or alternatively be a single layer of material having a tubular shape (e.g., having a constant thickness). In general, winding the stock material in a curved form onto the curved surface of the substrate may include any manner and form of physical positioning of the stock material in a curved form to fit the stock material onto the curved surface while also positioning the stock material so that it abuts itself (e.g., two longitudinal edges) to form a spiral seam extending about the longitudinal axis of the substrate. Thus, for example, winding the stock material in a curved form onto the curved surface may include moving the stock material in a curved form by using any one or more of the various different guide systems described herein. Additionally or alternatively, winding the stock material in a curved form onto the curved surface may include pressing the stock material onto the curved surface via pressure applied by one or more pressure rollers described herein.

[0080] As shown in step 358, the exemplary method 300 may include joining the stock material of the curved form to at least itself along the spiral seam. In addition or alternatively, the stock material may be joined to the curved surface of the substrate along the spiral seam. Unless otherwise specified or obvious from the context, joining the stock material of the curved form to itself along the spiral seam may include any one or more of the various welding techniques described herein. As a specific example, joining the stock material of the curved form to itself may include welding the stock material of the curved form to itself and the curved surface of the substrate along the spiral seam. In some cases, the welding process may include a manual or automatic inspection (such as visual, ultrasonic, magnetic particle or other technology) performed after one layer has been applied and before the next layer is applied to cover or otherwise hinder the inspection of the weld. In addition or alternatively, the capping of the weld before the next layer is applied can be removed by using any one or more of a variety of manual and / or automatic techniques (e.g., by grinding off the capping material until the weld is flush with the surface of the layer being welded). For example, weld cap removal can be performed in conjunction with welding, and further or alternatively can be performed continuously as the tubular structure is formed, thereby reducing the time and cost required for weld cap removal. Removing the weld cap can help to make subsequent layers more closely conform to the substrate or previous layer, as the case may be, than if the weld cap was not removed.

[0081] Although the steps of the exemplary method 352 have been described with respect to securing a first layer of a wrap to a substrate, it will be appreciated that any one or more of the various steps of the exemplary method 352 may be repeated as desired to add additional layers of a wrap to a substrate. It will be appreciated, however, that with the repeated steps of placing a layer after the first layer, each subsequent layer is wound over the previous layer in the stack of layers, and each layer may form a spiral seam that is different from the spiral seam formed by the previous layer.

[0082] It has been described that the tubular structure 104 is formed based on pre-bent layers of windings before positioning such layers on the substrate. Figure 1A-Figure 1D ), it is now of interest to form a tubular structure 104 ( Figure 1A-Figure 1D ) systems and methods.

[0083] Reference now Figure 4A and Figure 4B, the system 460 may include one or more instances of a tensioning roller 462, a rotator 464, a guide system 466, and a connector 468. Each instance of the tensioning roller 462 may be positioned to contact the planar form of the stock material 469 as the planar form of the stock material 469 moves in the feed direction "F" so as to apply tension to the planar form of the stock material 469. The rotator 464 may be actuated to rotate a curved surface (such as the second surface 112) of the substrate 106 about the longitudinal axis "L". The stock material 469 may be directly or indirectly attached to the curved surface of the substrate 106 such that as the rotator 464 rotates the curved surface of the substrate 106 in a direction away from the one or more instances of the tensioning roller 462, the rotation of the substrate 106 may pull the planar form of the stock material 469 from the stock source 470 toward the substrate 106 in the feed direction "F". As the curved surface of the substrate 106 continues to rotate, the planar form of the stock material 469 may be pulled onto the curved surface of the substrate 106 so as to cause the stock material 469 to bend along the first spiral seam 118a to form the first layer 116a.

[0084] Accurately positioning the stock material 469 along the first spiral seam 118 to form the first layer 116a (and for positioning along spiral seams associated with subsequent layers) can be advantageously achieved through a combination of the shape of the planar form stock material 469 and the operation of the guide system 466. That is, the planar form stock material 469 from the stock source 470 can include multiple sheets in non-linear end-to-end engagement with each other according to any one or more of a variety of different techniques. Specifically, unless otherwise specified or apparent from the context, the planar form stock material 469 and any stock material (e.g., Figure 2B The stock material 239 in the first spiral seam 118a may include a plurality of sheets in non-linear end-to-end engagement with each other according to a technique for arranging straight edge material sheets relative to each other to form a spiral seam, as described in U.S. Pat. No. 9,302,303, entitled “TAPERED STRUCTURE CONSTRUCTION,” issued to Smith et al. on April 5, 2016, the entire contents of which are incorporated herein by reference. In addition, between the one or more instances of the tensioning roller 462 and the substrate 106, a guide system 466 may adjust the position of the stock material 469 so that the stock material 469 is wound along the first spiral seam 118a.

[0085] After the curved surface of the substrate 106 is rotated to form the first layer 116a, it will be appreciated that similar rotation of the curved surface of the substrate 106 about the longitudinal axis "L" can form subsequent layers by drawing the planar form of the stock material 469 onto the first layer 116a. This process can be repeated as needed to form a winding including a predetermined number and position of layers to achieve a thickness distribution according to design specifications. In addition, the tight fit obtained by drawing the planar form of the stock material 469 onto the curved surface of the substrate 106 or onto the previous material layer can be used to increase the structural quality of the tubular structure being formed.

[0086] In general, the one or more instances of the tensioning roller 462 can be actuated to move perpendicular to the major surface of the planar form stock material 469 to increase or decrease tension in the planar form stock material 469, such as can be used to control the positioning of the stock material 469 along a spiral seam. Additionally or alternatively, the tension in the planar form stock material 469 moving in the feed direction "F" can be adjusted by controlling the resistance to rotation of the tensioning roller 462. The one or more instances of the tensioning roller 462 can define a gap through which the planar form stock material 469 can pass, and the position of the one or more instances of the tensioning roller 462 can be controlled so that the gap moves in a direction perpendicular to the feed direction "F". Additionally or alternatively, each instance of the tensioning roller 462 can rotate at least about an axis transverse to the feed direction "F".

[0087] The spinner 464 may, for example, include one or more rollers that are drivable to rotate the substrate 106 at a controlled speed about the longitudinal axis "L". Additionally or alternatively, at least a portion of the spinner 464 may support the substrate 106 as the substrate 106 rotates to wind the stock material 469 along the spiral seam. For example, the spinner 464 may support at least each end of the substrate 106.

[0088] The guide system 466 may include an actuator 471 that is controllable to cause the planar form of the stock material 469 to be wound along a spiral seam extending about the longitudinal axis “L” of the substrate 106. The actuator 471 may, for example, control the position of the planar form of the stock material 469 in a direction transverse to the feed direction “F”, such as may be used to achieve fine adjustment of the stock material 469 to position the longitudinal edges of the stock material 469 adjacent to each other to form a spiral seam as the stock material 469 is wound onto the substrate 106 through the rotation of the substrate 106. The actuator 471 may include, for example, one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof.

[0089] Additionally or alternatively, the guide system 466 may include a sensor 472 operable to sense a parameter indicative of a position of the planar form of the stock material 469. The actuator 471 may be adjusted based on a signal from the sensor 472 to adjust the position of the planar form of the stock material 469 as the tubular structure is being formed. For example, the sensor 472 may sense the position of the planar form of the stock material 469 at a point just before the stock material 469 is wrapped along the spiral seam. Additionally or alternatively, the sensor 472 may sense the position of the stock material 469 (e.g., a longitudinal edge of the stock material 469) along the spiral seam formed by the stock material 469. The sensor 472 may include, for example, an optical sensor, a camera as part of a machine vision system, a contact sensor, or a combination thereof.

[0090] In general, the connector 468 can mechanically couple the stock material 469 to itself and / or the substrate 106 according to any one or more of the various techniques described herein. Thus, the connector 468 can include a welder that is operable to form any one or more of the various welds described herein. For example, with respect to securing the stock material 469 to the substrate 106, the connector 468 can form the weld 120b ( Figure 1D ). It will be appreciated that the connector 468 may similarly form other welds associated with adding subsequent layers as needed to form a wrap around the substrate 106 to achieve a tubular structure having a predetermined strength profile.

[0091] Although one or more aspects of the operation of the system 460 may be performed by an operator through manual operation, in some embodiments, the system 460 may include a control system 473 to facilitate accurate and repeatable control of certain aspects of the operation of the system 460. The control system 473 may, for example, include a processing unit 474 and a storage medium 475 in communication with the processing unit 474. The processing unit 474 may include one or more processors, and the storage medium 475 may include a non-transitory computer-readable storage medium. The storage medium 475 may store computer-executable instructions that, when executed by the processing unit 474, cause the system 460 to perform one or more of the various different aspects of manufacturing a tubular structure using the system 460. Optionally, the control system 473 may include an input device (e.g., a keyboard, a mouse, and / or a graphical user interface) in communication with the processing unit 474 and the storage medium 475, so that as the processing unit 474 performs one or more of the manufacturing methods described herein, the processing unit 474 additionally or alternatively responds to input received through the input device.

[0092] Figure 5576 is a flow chart of an exemplary method 576 for forming a tubular structure. Unless otherwise specified or apparent from the context, any one or more aspects of the exemplary method 576 may be implemented as computer-readable instructions stored on the storage medium 475 ( Figure 4A ) and can be controlled by the control system 473 ( Figure 4A ) processing unit 474 ( Figure 4A ) is executed to operate the system 460 ( Figure 2A ) to form a reference Figure 1A-Figure 1D A tubular structure 104 is depicted.

[0093] As shown in step 577, exemplary method 576 may include joining (e.g., welding) a plurality of sheets (e.g., trapezoidal-shaped metal sheets) in an end-to-end engagement with each other to produce a planar form of inventory material. In such a case, end-to-end joining should be understood to include joining the short edge of one sheet with the short edge of another sheet to form a seam that is transverse to the parallel long edges of each sheet. Such joining may include, for example, welding the sheets together according to any one or more of the various different welding techniques described herein. As indicated above, the nonlinear end-to-end joining of a plurality of sheets may include an orientation in which straight edges (e.g., parallel straight edges) may be bent to form a spiral seam. In certain embodiments, a plurality of sheets may be joined in a nonlinear end-to-end engagement with each other such that the longitudinal edge of each sheet is transverse to the longitudinal edge of at least another sheet. In addition or in lieu thereof, a plurality of sheets may be joined in a linear end-to-end engagement with each other such that the longitudinal edge of each sheet is colinear with the longitudinal edge of each other sheet. Additionally or alternatively, where the tubular structure being formed is a true cylinder, a single sheet may be used as stock material in planar form.

[0094] As shown in step 578, exemplary method 576 may include securing the stock material to a curved surface of a substrate defining a longitudinal axis. It may be desirable to permanently secure the stock material to the curved surface using one or more techniques to reduce the likelihood that the stock material will accidentally become detached from the curved surface when tension is applied to the stock material. For example, the stock material may be secured to the curved surface of the substrate using one or more welding techniques described herein.

[0095] As shown in step 579, exemplary method 576 may include rotating the curved surface of the substrate about the longitudinal axis of the substrate. In the case where the stock material is fixed to the substrate (e.g., directly or indirectly fixed to the curved surface of the substrate), it will be appreciated that the rotation of the curved surface of the substrate can cause the planar form of the stock material to bend about the curved surface of the substrate. That is, the stock material can bend about the curved surface of the substrate so that the stock material and the substrate together form at least a portion of the tubular structure being formed. In the case of the first layer, the bending of the planar form of the stock material about the curved surface of the substrate can cause the stock material to fit directly to the curved surface of the substrate. In addition or alternatively, for subsequent layers, the bending of the planar form of the stock material about the curved surface of the substrate can cause the stock material to fit directly to the previous layer of stock material fixed to the substrate. In certain embodiments, by controlling the position of the stock material as the stock material bends about the curved surface of the substrate, the first longitudinal edge and the second longitudinal edge of the stock material can form a spiral seam about the longitudinal axis of the substrate so that the stock material and the substrate together form at least a portion of the tubular structure being formed.

[0096] As shown in step 580, exemplary method 576 may include, with the stock material secured to the substrate, moving the planar form of the stock material through one or more tension rollers as the curved surface of the substrate rotates about a longitudinal axis. The one or more tension rollers may be adjustable, for example, to adjust the amount of tension in the planar form of the stock material to help achieve a tight fit of the stock material moved onto the curved surface of the substrate.

[0097] As shown in step 581, exemplary method 576 may include joining the stock material to itself along the at least one spiral seam. For example, joining the stock material to itself along at least the at least one spiral seam may include welding the stock material to itself to form a weld coextensive with the spiral seam. Additionally or alternatively, joining the stock material to itself along the at least one spiral seam may include joining the stock material to a curved surface of a substrate, to a previous layer of stock material, or a combination thereof.

[0098] In general, unless otherwise specified or apparent from the context, it will be appreciated that any one or more of the various different steps in exemplary method 576 may be repeated as desired to wind multiple layers onto each other in any number and orientation of layers for forming a tubular structure having a predetermined strength distribution.

[0099] While certain implementations have been described, other implementations are possible, additionally or alternatively.

[0100] For example, while a planar form of stock material has been described as being wound onto a substrate to form a tubular structure, it will be appreciated that the planar form of stock material may additionally or alternatively be wound onto a reusable mandrel rather than a substrate that forms part of the final tubular structure. Continuing with this example, the process of adding material may be repeated using the first layer (formed on the mandrel) as the substrate until a tubular structure is formed having a winding including a number and location of layers as desired to achieve a predetermined strength profile for the tubular structure.

[0101] As another example, the reinforced tubular structure has been described as including a substrate and one or more layers wrapped around the substrate to give the substrate increased thickness and therefore increased strength, although additionally or alternatively, other methods of reinforcing the tubular structure are possible. For example, as described in the examples below, the tubular structure can include stabilizers disposed between multiple shells to give the tubular structure overall strength.

[0102] Reference now Fig. 6A and Figure 6B , the tubular structure 682 may include a first shell 683, a second shell 684, and a filler material 685. The second shell 684 may have a frustum-shaped shape, and the first shell 683 may be nested within the second shell 684 such that the first shell 683 and the second shell 684 define a gap therebetween. The filler material 685 may be disposed in the gap defined between the first shell 683 and the second shell 684. For example, the filler material 685 may fill the gap, such as may be used to achieve consistent strength characteristics of the tubular structure 682. Specifically, the filler material 685 may help transfer stress (e.g., shear stress) between the first shell 683 and the second shell 684. Additionally or alternatively, the filler material 685 disposed in the gap defined by the first shell 683 and the second shell 684 may reduce the likelihood of the first shell 683 and the second shell 684 buckling under a given load compared to the likelihood of the first shell 683 and the second shell 684 buckling under the same load when there is no filler material 685 between the first shell 683 and the second shell 684. That is, the tubular structure 682 can achieve strength and rigidity comparable to that of a tubular structure formed using thick solid metal walls. However, because the first shell 683 and the second shell 684 can have thin metal walls compared to a tubular structure formed using thick solid metal walls, the strength performance of the tubular structure 682 can generally be achieved at significantly less cost and significantly faster production time than if a tubular structure were formed using thick solid metal walls to achieve the same strength performance.

[0103] Generally speaking, one or both of the first shell 683 or the second shell 684 can be formed by using a spirally formed stock material strip. In some cases, the first shell 683 and the second shell 684 can be concentrically aligned with each other so that the gap defined between the first shell 683 and the second shell 684 is substantially symmetrical about the central axis "C" defined by the first shell 683 and the second shell 684. Among other things, such symmetry can generally be used to form a tubular structure 682 with substantially straight strength in the circumferential direction around the frustum shape of the second shell 684. In some cases, the second shell 684 can surround the first shell 683 so that the gap formed by the first shell 683 and the second shell 684 is annular, and such an annulus can be used to accommodate the filler material 685 between the first shell 683 and the second shell 684 and keep it away from external conditions. As a more specific example, the first shell 683 can be substantially parallel to the second shell 684 along the longitudinal axis (e.g., the central axis "C") defined by the first shell 683. That is, the first shell 683 can have a frustum shape that is parallel to the frustum shape of the second shell 684, so that the gap between the first shell 683 and the second shell 684 is also frustum. With other frustum shapes described herein, the frustum shape of the gap between the first shell 683 and the second shell 684 can be used to achieve strength performance using less material and therefore ultimately less cost.

[0104] The filler material 685 may, for example, include a material that is bonded to the first shell 683, the second shell 684, or a combination thereof. The filler material may include any one or more of a variety of different types of materials that can be bonded to the metal and simultaneously have the desired strength characteristics for a given final application. As an example, the filler material may include a material having consistent strength characteristics throughout the entire volume of the filler material. Some material examples for filler materials include cement, filled epoxy resin, cement slurry, high-density foam, sand, or a combination thereof. In some cases, the filler material may include a plurality of constituent components that are spatially separated from each other, wherein such spatial separation of the constituent components is used to achieve a target strength distribution in a longitudinal direction parallel to the central axis "C". Continuing with this example, the constituent components of such filler materials may include different concrete components arranged in a bottom layer in a direction parallel to the central axis "C".

[0105] Reference now Figures 7A-7C , the tubular structure 787 may include a first shell 788, a second shell 789, and a plurality of structural elements 790 (e.g., steel rods, ribs, tubes, or a combination thereof). Unless otherwise specified or apparent from the context, the first shell 788 and the second shell 789 may be similar to those described above with respect to Figure 6A-6BThe first shell 683 and the second shell 684 are arranged relative to each other in any one or more of the arrangements described. Thus, for example, the second shell 789 can have a frustum shape, and the first shell 788 can be nested in the second shell 789 so that a gap 791 is defined between the first shell 788 and the second shell 789. A plurality of structural elements 790 can be coupled to each of the first shell 788 and the second shell 789 and extend through the gap 791. Through such coupling, each of the plurality of structural elements 790 can help transfer shear loads and / or reduce the possibility of buckling of each shell. More specifically, in the case where the plurality of structural elements 790 couple the first shell 788 and the second shell 789, the tubular structure 787 can achieve structural properties similar to those of a tubular structure formed using a thick solid metal wall. Therefore, as other examples described herein, the tubular structure 787 can help achieve structural properties comparable to those of a tubular structure formed using a thick solid metal wall while significantly reducing production costs.

[0106] In some cases, the first shell 788 can define a plurality of first holes 792 and the second shell 789 can define a plurality of second holes 793 aligned with the plurality of first holes 792. Continuing with this example, each of the plurality of structural elements 790 can extend through one of the plurality of first holes 792 and a corresponding one of the plurality of second holes 793, such as can be used to install and / or replace the structural element 790 in the gap 791 without requiring access to the gap 791. For example, each of the plurality of structural elements 790 can pass through the plurality of first holes 792 to the plurality of second holes 793, thereby coupling the first shell 788 and the second shell 789 to each other. Additionally or alternatively, each of the plurality of structural elements 790 can be welded or otherwise joined to each of the first shell 788 and the second shell 789 to strengthen the tubular structure 787 compared to the rigidity of the first shell 788 and the second shell 789 alone.

[0107] Although certain embodiments of the reinforced tubular structure have been described as including stabilizers positioned between the shells, it will be appreciated that the stabilizers may additionally or alternatively be disposed along the outer surface of the shells to form a tubular structure having structural properties comparable to those of a tubular structure formed using thick solid metal walls, while being cheaper and faster to produce than such a tubular structure formed using thick solid metal walls.

[0108] For example, now refer to Figure 8A-8C, the tubular structure 880 may include a shell 888 and a plurality of elongated ribs 889. The shell 888 may have a first surface 891 and a second surface 892 opposite to each other, and the first surface 891 may define a cavity 893. The shell 888 may have a tubular shape (e.g., a frustum shape) defining a longitudinal axis "L". The shell 888 may have a spiral seam 894 extending about the longitudinal axis "L", and each of the plurality of elongated ribs 889 may be coupled to the shell 888 (e.g., along one or both of the first surface 891 or the second surface 892) and wherein the longitudinal dimension of each elongated rib 889 is substantially coplanar with the longitudinal axis "L", such that the longitudinal dimension of each of the elongated ribs 889 extends across the spiral seam 894 of the shell 888 to provide structural support across the spiral seam 894. In certain embodiments, each of the elongated ribs 889 can have a notch to facilitate passing the spiral seam 894 of the shell 888 beneath the plurality of elongated ribs 889 , thereby reducing the likelihood of interfering with the tight fit between each of the plurality of elongated ribs 889 and the shell 888 .

[0109] The plurality of elongated ribs 889 can be spaced relative to each other along the shell 888 according to any spacing, such as can be used to achieve target structural performance. For example, the plurality of elongated ribs 889 can be connected to each other along a plurality of longitudinal seams 895 that are substantially coplanar with the longitudinal axis "L" defined by the tubular shape of the shell. As a more specific example, the plurality of elongated ribs 889 can be connected to each other to surround the shell 888, such as can be used to achieve substantially consistent strength around the circumferential portion of the shell 888. Although any one or more of a variety of different techniques can be used to connect the plurality of elongated ribs 889 to the shell 888, in some embodiments, the longitudinal seams 895 can be formed by welding the plurality of elongated ribs 889 to the shell 888 using full welding or skip welding.

[0110] In some embodiments, each of the elongated ribs 889 can be V-shaped, having a first leg 896 and a second leg 897 coupled to each other at an apex 898, and the first leg 896 and the second leg 897 are coupled to the housing 888 so that the apex 898 points in a radial direction away from the housing 888. Continuing with this example, the elongated ribs 889 can be formed into a V-shape by using a press brake. Additionally or alternatively, the elongated ribs 889 can be roll-formed, or formed from a pair of flat strips of material joined (e.g., welded) together at the apex 898.

[0111] The above systems, devices, methods, processes, etc. can be implemented in hardware, software, or any combination thereof suitable for the control, data acquisition, and data processing described herein. This includes implementation in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors, or other programmable devices or processing circuits together with internal and / or external memory. This can also or alternatively include one or more application-specific integrated circuits, programmable gate arrays, programmable array logic components, or any one or more other devices that can be constructed to process electronic signals. It will be further appreciated that the implementation of the above-mentioned process or device may include a computer executable code created using a structured programming language, such as C, an object-oriented programming language such as C++, or any other high-level or low-level programming language (including assembly language, hardware description language, and database programming language and technology), which can be stored, compiled, or interpreted to run on one of the above-mentioned devices and on a heterogeneous combination of processors, processor architectures, or a combination of different hardware and software. At the same time, processing can be distributed on multiple devices, such as the various systems described above, or all functions can be integrated into a dedicated independent device. All these permutations and combinations are intended to fall within the scope of the present disclosure.

[0112] Embodiments disclosed herein may include a computer program product including computer executable or computer usable code that, when executed on one or more computing devices, performs any and / or all of the steps of the control system described above. The code may be stored in a non-transitory manner in a computer memory (which may be a memory from which the program is executed (such as a random access memory associated with a processor)) or in a storage device (such as a hard drive, flash memory, or any other optical, electromagnetic, magnetic, infrared or other device or combination of these devices). In another aspect, any of the above control systems may be implemented as any suitable transmission or propagation medium that carries the computer executable code and / or any input or output therefrom.

[0113] The method steps of the embodiments described herein are intended to include any suitable method of causing the method steps to be performed, consistent with the patentability of the following claims, unless a different meaning is expressly provided or the context clearly indicates otherwise. Thus, for example, performing step X includes any suitable method of causing another party (such as a remote user, a remote processing resource (e.g., a server or cloud computer), or a machine) to perform step X. Similarly, performing steps X, Y, and Z may include any method of directing or controlling these other individuals or resources to perform steps X, Y, and Z to obtain any combination of the benefits of these steps. Thus, the method steps of the embodiments described herein are intended to include any suitable method of causing one or more other parties or entities to perform the steps, consistent with the patentability of the following claims, unless a different meaning is expressly provided or the context clearly indicates otherwise. These parties or entities do not have to be under the direction or control of any other party or entity, and do not have to be located in a particular jurisdiction.

[0114] It will be appreciated that the above methods and systems are illustrated by way of example and are not restrictive. Many changes, additions, omissions and other modifications will be apparent to one of ordinary skill in the art. In addition, the order or presentation of the method steps in the specification and drawings above is not intended to require the steps to be performed in this order, unless a specific order is explicitly required or otherwise clearly stated in the context. Therefore, although specific embodiments have been shown and described, it will be apparent to those skilled in the art that various changes and modifications in form and detail may be made therein without departing from the spirit and scope of the present disclosure and that the various changes and modifications are intended to form a part of the present invention, which is to be interpreted in the broadest sense permitted by law.

Claims

1. A tubular structure comprising: a substrate having first and second surfaces opposite to each other, the first surface defining an elongated cavity, and the substrate having a tubular shape defining a longitudinal axis extending along the elongated cavity; as well as A winding supported on the second surface of the substrate, the winding comprising at least one layer, each layer having a first longitudinal edge and a second longitudinal edge connected to each other along a corresponding spiral seam associated with a given layer and extending around the longitudinal axis of the substrate, and each layer is welded to the substrate, at least one other layer, or a combination thereof.

2. The tubular structure of claim 1, wherein the common thickness of the wrap and the substrate varies in a direction parallel to the longitudinal axis of the substrate.

3. The tubular structure of claim 2, wherein the thickness of the wrap varies in a direction parallel to the longitudinal axis of the substrate.

4. The tubular structure of claim 3, wherein the thickness of the substrate is substantially constant in a direction parallel to the longitudinal axis of the substrate.

5. The tubular structure of claim 3, wherein the thickness of the wrap varies monotonically in a direction parallel to the longitudinal axis of the substrate.

6. The tubular structure of claim 5, wherein the tubular shape of the base comprises a frustum tapering in a direction parallel to the longitudinal axis, and the thickness of the wrap decreases monotonically in the direction of tapering of the frustum.

7. The tubular structure according to claim 2, wherein the at least one layer is a plurality of layers, and the plurality of layers are at least partially stacked on each other in a radial direction.

8. The tubular structure of claim 7, wherein each of the multiple layers surrounds the substrate at least once.

9. The tubular structure of claim 7, wherein the number of layers in the plurality of layers varies in a direction parallel to the longitudinal axis of the substrate.

10. The tubular structure of claim 7, wherein the respective spiral seams of a given layer are longitudinally offset from the respective spiral seams of each layer adjacent to the given layer.

11. The tubular structure of claim 1 , wherein the base includes a seam extending about the longitudinal axis of the base.

12. The tubular structure of claim 11, wherein the respective spiral seams of the at least one layer of the wrap are longitudinally spaced apart from the seams of the base along the longitudinal axis.

13. The tubular structure of claim 11, wherein the seams of the base are parallel to corresponding spiral seams of at least one layer of the wrap.

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