Tubular structure

Abstract

To provide a tubular structure which is suitable for manufacture with good cost efficiency in a short time, and can endure a high load.SOLUTION: A tubular structure 104, a system and a method are generally directed to a support structure which is formed by a material that is suitable for rounding and welding, and has a thickness useful for manufacture with good cost efficiency in a short time, and has structural characteristics similar to a thick structure. Especially, the tubular structure includes a tubular base part 106 and a lap 108 supported on the base part.SELECTED DRAWING: Figure 1C

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 966,803, filed on January 28, 2020, the entire content of which is incorporated herein by reference.

Background Art

[0002] Many applications of large support structures have thick tubular walls. For example, offshore wind turbines require large and thick - walled (thick - walled) support towers and foundations because such wind turbines are large in size and subject to high loads. The process for fabricating these support structures is costly and requires a great deal of time, and it is necessary to roll and weld thick steel plates (for example, 30 mm to 100 mm). Rolling a plate of such thickness requires the use of expensive special equipment to generate a large force. Also, welding thick plates requires a large number of welding passes, making the process very long and thus increasing the manufacturing cost.

[0003] Therefore, it is necessary to form a support structure that is suitable for cost - effective manufacturing in a short time and at the same time can withstand high loads.

[0004] Summary Tubular structures, systems, and methods generally are formed using materials having a thickness suitable for rolling and welding and thus useful for cost - effective manufacturing in a short time, while targeting support structures having structural characteristics similar to those of thick - walled structures.

[0005] According to one aspect, a tubular structure has a first surface and a second surface facing each other, the first surface defining an elongated cavity and having a tubular shape defining a longitudinal axis extending along the elongated cavity, a base, and a wrap supported on the second surface of the base, the wrap including at least one layer, each layer having a first longitudinal edge and a second longitudinal edge coupled to each other along individual helical seams associated with the given layer and extending around the longitudinal axis of the base.

[0006] In some embodiments, the combined thickness of the wrap and the base can vary in a direction parallel to the longitudinal axis of the base. For example, the thickness of the wrap can vary in a direction parallel to the longitudinal axis of the base. Further or alternatively, the thickness of the base is substantially constant in a direction parallel to the longitudinal axis of the base. Further or instead, the thickness of the wrap can vary monotonically in a direction parallel to the longitudinal axis of the base. As an example, the tubular shape of the base includes 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.

[0007] In certain embodiments, the at least one layer can be a plurality of layers, the plurality of layers being at least partially stacked on top of each other in a radial direction. For example, each layer of the plurality of layers can surround the base at least once. Further or alternatively, the number of layers of the plurality of layers can vary in a direction parallel to the longitudinal axis of the base. Further or instead, each layer of the plurality of layers can be joined to the base, to at least one other layer of the plurality of layers, or a combination thereof. Further or instead, each layer of the plurality of layers can be welded to the base, to another layer of the plurality of layers, or a combination thereof. Optionally, the individual helical seams of a given layer can be longitudinally offset from the individual helical seams of each layer adjacent to the given layer.

[0008] In some embodiments, the base can include a seam that extends around the longitudinal axis of the base. For example, the individual helical seams of at least one layer of wrap can be longitudinally spaced from the seam of the base along the longitudinal axis. Further or alternatively, the seam of the base can be parallel to the individual helical seams of at least one layer of wrap.

[0009] According to another aspect, a system for forming a tubular structure includes a drive system including a drive roll operable to move a material in a planar form in a supply direction, a bending device arranged to receive the material in a planar form moving in the supply direction and controllable to bend the material in a planar form to produce a material in a curved form, a plurality of support rolls operable to rotatably support a curved surface of the material, and one or more pressure rolls arranged to receive the material in a curved form from the bending device, the one or more pressure rolls being movable to press the material in a curved form from the bending device against the curved surface of the material rotatably supported on the plurality of support rolls. In some embodiments, the system can further include a joining device arranged to join the material in a curved form to itself, to a curved surface rotatably supported on the plurality of support rolls, or a combination thereof. Further or alternatively, the system can further include a guiding system arranged to receive the material in a curved form from the bending device, the guiding system including an actuator controllable to wind the material in a curved form along an individual helical seam of a given layer of the tubular structure being formed. The actuator can include, for example, one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof. Optionally, the guiding system can further include a sensor configured to detect a parameter indicative of the position of the material in a curved form along an individual helical seam, the actuator being in electrical communication with the sensor and adjustable based on a signal from the sensor to adjust the position of the material in a curved form along an individual helical seam of a given layer of the tubular structure being formed.

[0010] According to another aspect, a method of forming a tubular structure can include bending a portion of a stock material in a planar form into a stock material in a curved form, wrapping the stock material in the curved form around a base surface to form a helical seam about a longitudinal axis defined by the base, and joining the stock material in the curved form to at least itself along the helical seam.

[0011] In certain embodiments, wrapping the stock material in the curved form around the base surface can include pressing the stock material in the curved form against the base surface.

[0012] In some embodiments, joining the stock material in the curved form to at least itself along the helical seam can include joining the stock material in the curved form to the base surface.

[0013] In certain embodiments, joining the stock material in the curved form to at least itself can include welding the stock material in the curved form to itself along the helical seam.

[0014] According to another aspect, a system for forming a tubular structure can include a tension roller that can be disposed in contact with a stock material in a planar form as the stock material moves in a supply direction, a rotator that can be actuated to rotate a base surface about a longitudinal axis defined by the base, a guiding system that can include an actuator controllable to wrap the stock material in the planar form along a helical seam about the longitudinal axis of the base, and a joining device disposed to join the stock material to at least itself along the helical seam as the tubular structure is being formed.

[0015] In some embodiments, the actuator can include one or more edge guides, one or more edge rollers, one or more pinch rollers, or combinations thereof.

[0016] In certain embodiments, the guiding system can further include a sensor configured to detect a parameter indicating the position of the material along the helical seam, and the actuator is in electrical communication with the sensor and is adjustable based on a signal from the sensor to adjust the position of the planar material along the helical seam when the tubular structure is being formed.

[0017] According to yet another aspect, a method of forming a tubular structure can include joining a plurality of plates in a non-linear butting engagement with each other to produce a material in a planar form, fixing the material to a curved surface of a base defining a longitudinal axis, and rotating the curved surface of the base about the longitudinal axis of the base with the material fixed to the base, such that as the curved surface of the base rotates, the first longitudinal edge and the second longitudinal edge of the material form at least one helical seam around the longitudinal axis of the base while the material in the planar form is bent around the curved surface of the base. In some embodiments, the method can further include moving the material in the planar form through one or more tension rollers while the material is fixed to the base and the curved surface of the base is rotating about the longitudinal axis. Further or alternatively, the method can further include joining the material to itself along at least one helical seam. Optionally, joining the material to itself along at least one helical seam can further include joining a layer of the material to the curved surface of the base, to a previous layer of the material, or a combination thereof.

[0018] According to yet another aspect, a tubular structure can include a first shell and a second shell having a frustoconical shape, with the first shell nested within the second shell such that the first shell and the second shell define a gap therebetween, and a stabilizer disposed within the gap, the stabilizer maintaining the positions of the first shell and the second shell relative to each other.

[0019] In some embodiments, the first shell can be substantially parallel to the second shell along a longitudinal axis defined by the first shell.

[0020] In certain embodiments, the stabilizer can include a filling material coupled to the first shell, the second shell, or a combination thereof.

[0021] In some embodiments, the stabilizer can include a plurality of structural elements that extend through a gap and are coupled to each of the first shell and the second shell. For example, the first shell can define a plurality of first holes, the second shell can define a plurality of second holes that are aligned with the plurality of first holes, and each of the plurality of structural elements can extend through one of the plurality of first holes and a corresponding one of the plurality of second holes.

[0022] According to yet another aspect, a tubular structure can include a shell having a first surface and a second surface, the first surface defining an elongated cavity, the first surface facing the second surface, the shell having a tubular shape defining a longitudinal axis that extends along the elongated cavity and having a helical seam that extends around the longitudinal axis, and a plurality of elongated ribs, the plurality of elongated ribs being coupled to the shell with a longitudinal dimension of each elongated rib that is substantially parallel to the longitudinal axis defined by the tubular shape of the shell.

[0023] In some embodiments, the tubular shape of the shell can be frustoconical.

[0024] In certain embodiments, at least one of the plurality of elongated ribs can be fixed along the first surface of the shell.

[0025] In some embodiments, at least one of the plurality of elongated ribs can be fixed along the second surface of the shell.

[0026] In certain embodiments, the plurality of elongated ribs may be joined to each other along a plurality of longitudinal seams that are substantially in the same plane as the longitudinal axis defined by the tubular shape of the shell.

[0027] In some embodiments, each of the plurality of elongated ribs can be in a V-shape where a first leg and a second leg are joined to each other at a vertex, and the first leg and the second leg are joined to the shell.

Brief Description of the Drawings

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[0046] Like reference numerals in the various drawings indicate like elements.

[0047] Description Now, embodiments will be described in more detail below in connection with the accompanying drawings, in which exemplary embodiments are shown. However, the embodiments may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

[0048] All documents mentioned in this specification are hereby incorporated by reference in their entirety. References to singular items are to be understood to include plural items, unless explicitly stated otherwise or obvious from the context, and vice versa. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, etc., unless explicitly stated otherwise or obvious from the context. Thus, the term "or" is generally to be understood to mean "and / or", and the term "and" is generally to be understood to mean "and / or".

[0049] In this specification, the description of a range of values is not intended to be limiting; instead, unless otherwise indicated herein, any and all values within the range are individually meant and each separate value within such range is incorporated into this specification as if it were individually recited herein. The words “about,” “substantially,” or the like, when accompanying a numerical value, should be construed to include any deviation as would be understood by one of ordinary skill in the art for the intended purpose to operate satisfactorily. Ranges of values and / or numerical values are provided herein as examples only and do not constitute a limitation on the scope of the described embodiments. The use of any and all examples or exemplary language (such as “for example,” “such as,” or the like) is merely intended to better illustrate the embodiments and does not result in a limitation on the scope of these embodiments. The absence of a word in this specification should be construed as indicating no element essential for the implementation of the disclosed embodiments that is not recited in the claims.

[0050] As used herein, the term “tubular structure” should be understood to include any aspect and form of a structure having a two-dimensional outer shape (profile) that defines an elongated cavity and is substantially curved about a longitudinal axis extending along the elongated cavity. Thus, unless otherwise specified or apparent from the context, some examples of tubular structures include frustoconical and cylindrical (e.g., right circular cylinders). Unless otherwise indicated, the tubular shapes described herein can include shapes that approximate geometric ideals such as being bounded by curves, frustoconical, conical, or cylindrical. Such approximations of geometric ideals can include frustoconical approximations using deviations from the geometric ideals resulting from the stacking of layers of material and / or typical manufacturing tolerances.

[0051] Furthermore, as used herein, the terms "thickness" and variations thereof are to be understood as generally meaning the thickness (wall thickness) of a given material, and are to be understood in context. For example, with respect to a single layer, thickness is generally to be understood as meaning the wall thickness of the single layer, unless otherwise specified or apparent from the context. Further or alternatively, with respect to multiple layers, thickness is to be understood as meaning the total thickness of the multiple layers wrapped on top of each other, unless the contrary use is indicated. Further or instead, with respect to the tubular structures described herein, thickness is to be understood as meaning the total thickness of the tubular structure at a given point along the longitudinal axis, and thus when the case can be at a given point along the longitudinal axis, it may mean the wall thickness of only the base, or the combined thickness of the base supporting the wrap (package).

[0052] Furthermore, as used herein, the terms "longitudinal (longitudinal direction)" and "radial direction" are to be understood as meaning directions in a cylindrical coordinate system, unless the contrary intention is apparent from the context. Thus, in particular, a reference to the radial direction is to be understood as meaning a direction perpendicular to the longitudinal axis. Further or alternatively, the longitudinal direction associated with such a cylindrical coordinate system is to be understood as being parallel to the longitudinal axis associated with the structure being described. The longitudinal axis may correspond to the central axis of any given structure, but it should be recognized that this is not necessarily the case in a particular embodiment.

[0053] The devices, systems, and methods of the present disclosure are described in the context of a tubular structure useful as a tower for large wind turbines (e.g., offshore wind turbines) that can withstand high loads. More specifically, for the benefit of clear and efficient explanation, aspects of the present disclosure are generally described in the context of a frustum of a cone, but should be understood to be equally applicable to a cylinder (circular cylinder) unless the contrary intention is indicated. Further, for clarity of illustration, the tubular structure is shown as a one-piece structure. However, unless the contrary intention is indicated, any one or more of the various different frustums of a cone described herein should be understood to be manufacturable as assembled components according to the dimensional requirements of a given end use. Further, unless otherwise specified or apparent from the context, such tubular structures described herein can be used in any one or more of a variety of different applications that require high strength and / or high rigidity, such as a socket for a wind turbine or other support structure, or more generally, a tubular structure useful for large civil structures, pipelines, pressure vessels, etc.

[0054] Now, referring to FIGS. 1A - 1D, the wind turbine assembly 100 can include a wind turbine 102 and a tubular structure 104. The wind turbine 102 can be supported by the tubular structure 104, in which case the tubular structure 104 withstands the load conditions associated with the movement of the wind turbine 102 and the installation environment. In some cases, the tubular structure 104 can have a diameter that decreases along the length of the tubular structure 104 such that the top to which the wind turbine 102 is attached is smaller in diameter than the bottom to which the tubular structure 104 is fixedly secured to the ground or another rigid surface. Taper - ing the diameter of the tubular structure 104 longitudinally can be useful, for example, to provide structural strength to support the loads applied to the tubular structure 104 in the field while also addressing competing considerations of efficient use of materials. However, the strength profiles achievable using longitudinal tapering can be subject to certain limitations (e.g., dimensional constraints related to transportation and / or installation). Thus, as will be described in more detail later, the material thickness of the tubular structure 104 can be further or alternatively varied to facilitate achieving a predetermined strength profile of the tubular structure 104 while taking into account practical considerations such as installation time and cost.

[0055] The tubular structure 104 can include a base 106 and a wrap 108. The base 106 can have a first surface 110 and a second surface 112 that face each other, in which case the distance between the first surface 110 and the second surface 112 defines the thickness of the base 106. The first surface 110 of the base 106 can define an elongated cavity 114, and the base 106 can have a tubular shape that defines a longitudinal axis "L" extending along the elongated cavity 114. The wrap 108 can include a plurality of layers 116a, b, c, d (collectively referred to as the plurality of layers 116a, b, c, d and individually referred to as the first layer 116a, the second layer 116b, the third layer 116c, and the fourth layer 116d), and the wrap 108 can be supported on the second surface 112 of the base 106. That is, as will be described in more detail later, the first layer 116a can be supported on the second surface 112 of the base 106, the second layer 116b can be supported on the first layer 116a, the third layer 116c can be supported on the second layer 116b, and the fourth layer 116d can be supported on the third layer 116c. Although the tubular structure 104 will be described later as including a plurality of layers 116a, b, c, d, it should be recognized that this is for a clear and efficient explanation of a particular embodiment associated with the wrap 108 that includes a plurality of layers. However, unless otherwise specified, any of the following descriptions related to the plurality of layers 116a, b, c, d should be understood to be applicable to embodiments that include only a single example of a layer and / or embodiments that include more than four layers. Additionally or alternatively, for the sake of clear and efficient explanation, each of the plurality of layers 116a, b, c, d should be understood to have the same nominal composition as each other and can have various nominal thicknesses that vary relative to one another in order to achieve a given thickness profile (shape) of the tubular structure 104 in a direction parallel to the longitudinal axis "L".

[0056] With the wrap 108 supported on the base 106, the tubular structure 104 can have a strength similar to that of another identically dimensioned structure formed using a thick material having the same material thickness as the combined material thickness of the plurality of layers 116a, b, c, d and the base 106. However, the wrap 108 supported on the base 106 offers significant advantages compared to handling a thick material to achieve a target thickness profile (e.g., strength profile) in the longitudinal direction. For example, since each of the plurality of layers 116a, b, c, d is individually thinner than a thick material, each of the plurality of layers 116a, b, c, d can be rolled, welded, or otherwise processed relatively easily compared to a thick material. That is, achieving the target total thickness using the wrap 108 disposed on the base 106 can reduce manufacturing time and / or manufacturing cost compared to achieving the target total thickness using a thick material. Similarly, each of the plurality of layers 116a, b, c, d can be sized to reduce or eliminate the need for special equipment that may be required to handle a thick material of a thickness comparable to that of the plurality of layers 116a, b, c, d.

[0057] Generally, the base 106 can be any one or more of a variety of different tubular shapes useful for supporting the plurality of layers 116a, b, c, d such that the combined tubular structure 104 can have a predetermined thickness profile in a direction parallel to the longitudinal axis "L". For example, the base 106 can include a frustum of a cone, which itself has a strength profile that efficiently uses material to support the wind turbine 102, around which the wrap 108 is disposed to reinforce the wider end of the frustum of the cone (and thus add to the achievable strength difference between the wider end of the frustum of the cone and the narrow end of a frustum of the cone of a given dimension). Stated another way, the wrap 108 supported on the base 106 can advantageously decouple specific design constraints (e.g., strength vs. size) associated with forming a support structure using only a single layer of material.

[0058] In certain embodiments, the base 106 can have a substantially constant thickness in a direction parallel to the longitudinal axis "L" (e.g., allowing for the nominal manufacturing tolerances associated with commercially available sheet metal stock). Such a substantially constant thickness can be useful, for example, in forming the base 106 using any one or more of a variety of different material materials that can be readily and cost - effectively supplied. Further or alternatively, forming the base 106 with a constant thickness can be useful in quickly forming the base 106 using any one or more of a variety of different techniques and with little or no need for special equipment.

[0059] Generally, the plurality of layers 116a, b, c, d of the wrap 108 can be dimensioned relative to each other and relative to the base 106 to achieve a predetermined thickness profile of the tubular structure 104 in a direction parallel to the longitudinal axis "L". It should be noted that one or more of the plurality of layers 116a, b, c, d can extend along only a portion of the longitudinal dimension of the base 106 such that the thickness of the wrap 108 in the radial direction varies in a direction parallel to the longitudinal axis "L" to facilitate changing 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 can 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 this example, the tubular structure 104 has a first overall thickness t along the first end portion 117 1 , a second overall thickness t along the second end portion 119 2 and in this case, the first overall thickness t 1 is the second overall thickness t 2is greater. One or more of the plurality of layers 116a, b, c, d can have a constant wall thickness in a direction parallel to the axis "L", but it should be recognized that one or more of the plurality of layers 116a, b, c, d can have a wall thickness that at least varies along a portion of the longitudinal dimension of a given layer. Further or alternatively, each of the plurality of layers 116a, b, c, d can have the same thickness profile as each other, but it should be recognized that one or more of the plurality of layers 116a, b, c, d can have a thickness profile that is different from at least one other 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 can have any one or more of a variety of different thickness profiles in a direction parallel to the longitudinal axis "L" as necessary or useful to achieve the overall thickness profile of the wrap 108.

[0060] In the particular example shown in FIG. 1C, the plurality of layers 116a, b, c, d of the wrap 108 are supported on the base 106 in a wound configuration, and in that wound configuration, the plurality of layers 116a, b, c, d of the wrap are at least partially stacked radially on top of each other, resulting in a thickness profile of the tubular structure 104 having five different thicknesses in a direction parallel to the longitudinal axis "L", where in this case, a first thickness t along a first end portion 117 of the tubular structure 104 1 corresponds to the combined thickness of the base 106 and all of the plurality of layers 116a, b, c, d, but a second thickness t along a second end portion 119 of the tubular structure 104 2 corresponds to the wall thickness between the first surface 110 and the second surface 112 of the base 106.

[0061] Each of the plurality of layers 116a, b, c, d can have a first longitudinal edge 113 and a second longitudinal edge 115 that are joined to each other such that each of the plurality of layers 116a, b, c, d surrounds 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 can be joined to each other along respective plural spiral seams 118a, b, c, d (collectively referred to as the plural spiral seams 118a, b, c, d and individually referred to as the first spiral seam 118a, the second spiral seam 118b, the third spiral seam 118c, and the fourth spiral seam 118d). That is, the first layer 116a can form the first spiral seam 118a, the second layer 116b can form the second spiral seam 118b, the third layer 116c can form the third spiral seam 118c, and the fourth layer 116d can form the fourth spiral seam 118d. Each of the plural spiral seams 118a, b, c, d can extend around the longitudinal axis "L" of the base 106 such that it is useful in forming each of the plural spiral seams 118a, b, c, d in the process of continuously or substantially continuously joining (bonding) the base 106 while the base 106 rotates about the longitudinal axis "L" according to any one or more of the various different techniques described herein.

[0062] In certain embodiments, the plurality of layers 116a, b, c, d can be joined to the base 106 and / or to each other such that they are useful for efficiently dispersing an external load across the tubular structure 104. For example, the plurality of layers 116a, b, c, d can be joined to the base 106 and / or to each other with plural welds 120a, b, c, d, e (collectively referred to as the plural welds 120a, b, c, d, e and individually referred to herein as the first weld 120a, the second weld 120b, the third weld 120c, the fourth weld 120d, and the fifth weld 120e). As used in this context, the term "weld" should be understood to mean a joint formed between at least two adjacent portions of material.

[0063] For example, the first weld 120a can be a double-sided weld used to join the base 106 to itself along the seam 122 such that the base 106 can be a stable structure where a plurality of layers 116a, b, c, d of the wrap 108 can be disposed and the plurality of layers 116a, b, c, d can be directly or indirectly secured to form the tubular structure 104. In some cases, the seam 122 of the base 106 can be a helical seam useful for fabricating the base 106 using any one or more of a variety of different automated techniques as described in U.S. Patent No. 9,302,303, titled "TAPERED STRUCTURE CONSTRUCTION," issued to Smith et al. on April 5, 2016, the entire content of which is incorporated herein by reference. Additionally or alternatively, the first weld 120a can be formed as part of a process different from the process used to secure the plurality of layers 116a, b, c, d to the base 106. Thus, the first weld 120a can correspond to the helical seam of the base 106, but it should be recognized that such a helical seam may not necessarily be used on the base 106 assuming that the base 106 may not be formed as part of a continuous or substantially continuous process where the helical seam is useful. Additionally or alternatively, the second weld 120b can enter into the base 106 and into the first helical 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 can have a spread substantially the same as the first helical seam 118a. Similarly, the third weld 120c can have the same spread along the second helical seam 118b for joining 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 can be joined to each other via the fourth weld 120d and the fifth weld 120e.

[0064] Each of the first longitudinal edges 113 and the second longitudinal edges 115 of the plurality of layers 116a, b, c, d includes one or more feature elements that are useful for facilitating alignment and / or coupling of these edges with respect to each other. For example, each of the first longitudinal edge 113 and the second longitudinal edge 115 can include a single bevel such that when the first longitudinal edge 113 and the second longitudinal edge 115 of a given layer are aligned, a "V" shape is formed in which each of the second weld 120b, the third weld 120c, the fourth weld 120d, or the fifth weld 120e can be formed using a single-sided welding process. In the first layer 116a, preparation of such a "V" edge can facilitate, for example, simultaneously joining the first longitudinal edge 113 and the second longitudinal edge 115 to each other and to the base 106, resulting in better welding quality. Similarly, for each of the subsequent layers (the second layer 116b, the third layer 116c, and the fourth layer 116d), preparation of the "V" edge can facilitate simultaneously joining the first longitudinal edge 113 and the second longitudinal edge 115 to each other and to the preceding layer, along with a corresponding improvement in welding quality.

[0065] In some cases, the plurality of helical seams 118a, b, c, d can be longitudinally offset from each other in a direction parallel to the longitudinal axis "L" of the base 106. With such an offset, the plurality of seams 118a, b, c, d do not lie on top of each other in the radial direction extending from the longitudinal axis "L". This type of spacing can facilitate dispersing the stress caused by welding along the tubular structure 104 when the tubular structure 104 is formed, and thus facilitate quality control of the tubular structure 104.

[0066] Now, referring to FIGS. 2A and 2B, system 230 can include one or more examples of a drive system 232, a bending device 234, a plurality of support rollers 236, and a pressure roll 238. Unless otherwise specified or apparent from the context, system 230 can be operable to form the tubular structure 104 (FIGS. 1A-1D). For example, drive system 232 can be operable to move a planar form of the material stock 239 (e.g., from a material source 240) in a supply direction “F” to bending device 234, where the planar form of the material stock 239 can be pre-bent into a curved form of the material stock 239. The curved form of the material stock 239 can move between one or more examples of the pressure roll 238 and a curved surface 241 of the material supported on the plurality of support rollers 236 to ultimately form the wrap 108 (FIGS. 1A-1D) of the tubular structure 104 (FIGS. 1A-1D). That is, depending on the manufacturing stage and thickness profile of the tubular structure 104 (FIGS. 1A-1D) being formed using system 230, the curved surface 241 that receives the curved form of the material stock 239 can be the second surface 112 of the base 106 (FIGS. 1A-1D) or the surface of a preceding layer of the wrap 108 (FIGS. 1A-1D). Pre-rounding the material stock 239 with the bending device 234 to form the curved form of the material stock 239 can increase the degree to which the material stock 239 conforms to the curved surface 241 (e.g., to the base 106 in FIGS. 1A-1D and / or to a preceding layer of the plurality of layers 116a, b, c, d), increasing the strength, rigidity, and / or other desired properties of the formed tubular structure (e.g., the tubular structure 104 of FIGS. 1A-1D).

[0067] Generally, the drive system 232 can include a drive roll 233 operable to move the flat-form stock material 239 in the supply direction “F”. For example, the drive roll 233 can sandwich the flat-form stock material 239 such that rotation of the drive roll 233 can move the flat-form stock material 239 along the supply direction “F”. In certain embodiments, the supply direction “F” can be substantially invariant (constant) (e.g., using a drive roll 233 in a substantially stationary position when the rotation of the drive roll 233 moves the flat-form stock material 239 to and / or through the bending device 234). Additionally or alternatively, the supply direction “F” can be changed such that the flat-form stock material 239 undergoes a rotational movement and / or a substantial rotational movement as it moves to and / or through the bending device 234. Such a change in the supply direction “F” can be useful for aligning the edges of the stock material 239 to form any one or more of the helical seams described herein. Examples of such a change in the supply direction “F” to produce a rotational movement and / or a substantial rotational movement as part of the manufacturing process of a tubular structure are described in U.S. Patent No. 9,302,303, entitled “TAPERED STRUCTURE CONSTRUCTION,” issued to Smith et al. on April 5, 2016, and U.S. Patent No. 10,189,064, entitled “CONTROL SYSTEM AND METHOD FOR TAPERED STRUCTURE CONSTRUCTION,” issued to Takata et al. on January 29, 2019, the entire contents of each of which are incorporated herein by reference. More specifically, the flat-form stock material 239 can be moved from the stock source 240 to the bending device 234, and optionally through the bending device 234, using any equipment suitable for moving flat materials according to any of a variety of different techniques known in the art. Such equipment can include, for example, robotic arms, pistons, servo motors, screws, actuators, rollers, drivers, electromagnets, or combinations thereof.

[0068] The bending device 234 can be arranged to receive a flat-form stock material 239 that moves in the supply direction "F", and the bending device 234 can bend the flat-form stock material 239 supplied thereto to produce a curved-form stock material 239. As an example, the bending device 234 can bend the flat-form stock material 239 without causing in-plane deformation to the stock material 239. Further or alternatively, the bending device 234 can impart a controlled amount of curvature to the stock material 239 such that the curved-form stock material 239 can substantially match the curvature of the curved surface 241 along which it moves.

[0069] The bending device 234 can include, for example, roll sets 242a, 242b, 242c, which are arranged relative to each other and relative to the flat-form stock material 239 to impart curvature to the flat-form stock material 239 that is supplied through the roll sets 242a, 242b, 242c. In some cases, the roll sets 242a, 242b, 242c can be configured as three rolls, and further or alternatively, the roll sets 242a, 242b, 242c can be movable relative to each other to change the bending moment applied to the stock material 239 passing through the bending device 234. Each of the roll sets 242a, 242b, 242c can include, for example, a plurality of individual rollers that are rotatable independently of each other and are arranged along an individual axis defined by each of the roll sets 242a, 242b, 242c. Further or alternatively, the individual rollers of the roll sets 242a, 242b, 242c can be positionable relative to the individual axes defined by each of the roll sets 242a, 242b, 242c (e.g., through actuation signals received by a control system).

[0070] Generally, the support roller 236 can enable the curved surface 241 of the formed tubular structure to rotate with respect to the material 239 in a curved form that moves from the bending device 234 onto the curved surface 241. In some embodiments, one or more support rollers 236 can be actively controlled to rotate the curved surface 241 at a predetermined speed so as to be useful for providing tension to the material 239 in a curved form to facilitate closely disposing the material 239 in a curved form onto the curved surface 241. In some cases, one or more support rollers 236 can be passive such that the force of the material 239 in a curved form moving onto the curved surface 241 can rotate the curved surface 241 when the tubular structure is being formed.

[0071] Each of one or more examples of the pressure roll 238 can include one or more rollers movable to press against the material 239 in a curved form on the curved surface 241 rotatably supported on the plurality of support rollers 236. For example, at least one example of the pressure roll 238 can be rotatable about an axis parallel to the curved surface 241 of the base 106 to move the material 239 in a curved form from the bending device 234 onto the curved surface 241. Further or alternatively, at least one example of the pressure roll 238 can be movable radially with respect to the formed tubular structure, in which case the radial movement of at least one example of the pressure roll 238 is useful for controlling the degree of conformity between the material 239 in a curved form and the curved surface 241. In other words, the radial movement of at least one example of the pressure roll 238 can reduce the possibility of an unintentional gap between layers of the wrapped material and / or between the wrap and the base, in which case the reduced possibility of such a gap includes improved load-bearing performance.

[0072] In certain embodiments, the system 230 can include a joining device 244 arranged or configurable to join (e.g., mechanically couple) a material material 239 in a curved form to itself (e.g., along any one or more of the helical seams described above with respect to FIGS. 1A-1D). Additionally or alternatively, the joining device 244 can be arranged or configurable to join a material material 239 in a curved form to a curved surface 241 rotatably supported on a plurality of support rollers 236. As an example, the joining device 244 can be arranged between two examples of pressure rollers 238 to increase the likelihood of a tight fit between the material material 239 in a curved form and the curved surface 241 when the joining operation is performed. In some cases, the joining device 244 can continuously mechanically couple the materials to each other as the material material 239 in a curved form moves onto the curved surface 241 while rotating on the support rollers 236. Such continuous mechanical coupling can be useful, among other things, to achieve the targeted structural strength of the tubular structure being formed. Additionally or alternatively, the joining device 244 can be operable to intermittently (intermittently) join (e.g., at regular intervals) the materials along any one or more of the various different helical seams described herein, in which case such intermittent joining can be useful for higher throughput.

[0073] The joining device 244 can include, for example, a welding machine operable to form any one or more of the various different welds described herein. A wide variety of techniques for welding are known in the art and can be adapted to join any one or more edges as contemplated herein. This can include, for example, any welding technique that melts the base material or other material, optionally with a filler added to the joint to improve the strength of the bond, along any one or more of the various different seams described herein. Conventional welding techniques suitable for structurally joining metals include, by way of example and not limitation, gas metal arc welding (GMAW) including inert gas (MIG) and / or MAG (metal active gas); submerged arc welding (SAW); laser welding; and gas tungsten arc welding (also known as tungsten inert gas welding or "TIG" welding); and many others.

[0074] In certain embodiments, system 230 can include a guiding system 245 arranged to receive the stock material 239 in a curved form from the bending device 234. The guiding system 245 can include, for example, a controllable actuator 246 (e.g., in a direction substantially parallel to the longitudinal axis of the formed tubular structure) to wind the stock material 239 in a curved form along the individual helical seams of a given layer of wrap coupled to the base of the formed tubular structure. 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 combinations thereof. Optionally, the guiding system 245 can further include a sensor 247 operable to detect parameters indicative of the position of the stock material 239 in a curved form along the helical seam formed by the stock material 239 moving on the curved surface 241. Examples of the sensor 247 can include optical sensors, one or more cameras of a machine vision system, contact sensors, or combinations thereof. The actuator 246 can be adjustable based on signals from the sensor 247, for example, to effect corresponding adjustments to the position of the stock material 239 in a curved form along the helical seam formed as the stock material 239 in a curved form moves onto the curved surface 241.

[0075] One or more aspects of the operation of system 230 may be performed through manual operation by an operator, but system 230 can include, in some embodiments, a control system 248 to facilitate accurate and repeatable control of certain aspects of the operation of system 230. The control system 248 can include, for example, a processing unit 249 and a storage medium 250 that communicates with the processing unit 249. The processing unit 249 can include one or more processors, and the storage medium 250 can include a persistent computer-readable storage medium. The storage medium 250 can store computer-executable instructions that, when executed by the processing unit 249, cause the system 230 to perform one or more various different aspects related to the manufacture of tubular structures using the system 230. Optionally, the control system 248 can include an input device (e.g., a keyboard, a mouse, and / or a graphical user interface) that communicates with the processing unit 249 and the storage medium 250, and when the processing unit 249 executes one or more of the manufacturing methods described herein, the processing unit 249 is further or alternatively adapted to respond to inputs received via the input device.

[0076] FIG. 3 is a flow diagram of an exemplary method 352 of forming a tubular structure. Unless otherwise specified or apparent from the context, any one or more aspects of the exemplary method 352 may be embodied as computer-readable instructions stored in a memory medium 250 (FIG. 2A) and executable by a processing unit 249 (FIG. 2A) of a control system 248 (FIG. 2A) to operate the system 230 (FIG. 2A) to form the tubular structure 104 described in connection with FIGS. 1A-1D. In a particular embodiment, the exemplary method 352 can include certain preparation steps, which can include joining a plurality of plates to each other in a non-linear butting engagement to produce a planar material having a straight longitudinal edge that can be wound to form a helical seam. Additionally or alternatively, the exemplary method 352 can include securing the material to the curved surface of the base or to a previous layer, optionally at the start of the process of winding a given layer. For clarity and efficiency of explanation, these preparation steps will be described in more detail in connection with FIG. 5, assuming that such steps are more readily understood in connection with the hardware diagrams of FIGS. 4A and 4B used to implement the method represented in FIG. 5. However, unless otherwise instructed or apparent from the context, any one or more of the preparation steps described later in connection with FIG. 5 should be understood to be encompassed by the exemplary method 352 without departing from the scope of the present disclosure.

[0077] As shown in step 354, exemplary method 352 can include bending a portion of an elongate piece of stock material in a planar form into stock material in a curved form. Such bending can be performed, for example, by moving the stock material in a planar form to and through a bending device, such as bending device 234 (Figs. 2A and 2B). Through such bending, the stock material can approximate the curvature of a curved surface along which the stock material can be guided. For example, in an example where the tubular structure being formed is frustoconical, the elongate piece of stock material in a planar form can be bent into dimensions that vary progressively in accordance with corresponding changes in the dimensions of the frustoconical shape of the tubular structure being formed. In this regard, it should be recognized that while multiple layers wrapped around the base of the frustoconical shape may deviate from a geometric frustoconical shape, the resulting shape of the tubular structure having these features is nevertheless referred to herein as frustoconical.

[0078] As shown in step 356, exemplary method 352 can include wrapping a material in a curved form around the surface of a base (e.g., base 106 of FIGS. 1B and 1C) to form a helical seam about a longitudinal axis defined by the base. The base can be formed separately (e.g., via a can-rolling process or a helical welding process), or alternatively, can be a single layer of material having a tubular shape (e.g., having a constant thickness). Generally, wrapping a material in a curved form around the surface of the base can include any method and form of physically positioning the material in a curved form while positioning the material against itself (e.g., two longitudinal edges) to form a helical seam extending about the longitudinal axis of the base and conforming the material to the surface. Thus, for example, wrapping a material in a curved form around the surface can include moving the material in a curved form using any one or more of the various different guiding systems described herein. Additionally or alternatively, wrapping a material in a curved form around the surface can include pressing the material against the surface by pressure applied by one or more pressure rolls described herein.

[0079] As shown in step 358, exemplary method 300 can include joining (bonding) a material material in a curved form to itself along a helical seam. Additionally or alternatively, the material material can be joined to the curved surface of the base along the helical seam. Unless otherwise specified or apparent from the context, joining a material material in a curved form to itself along a helical seam can include any one or more of the various different welding techniques described herein. By way of example, joining a material material in a curved form to itself can include welding the material material in a curved form to itself and to the curved surface of the base along the helical seam. In some cases, the welding process can include inspections such as visual, ultrasonic, magnetic particle or other techniques, which are performed manually or automatically after one layer is added and before the next layer is added to hide the weld or otherwise obscure inspection of the weld. Additionally or alternatively, the cap of the weld can be removed using any one or more of the various different manual and / or automated techniques (e.g., by polishing and removing the cap material until the surface of the weld is flush with the surface of the layer to which the weld is made) before the next layer is added. For example, the removal of the weld cap can be performed inline with the weld, or alternatively, continuously as the tubular structure is being formed, reducing the time and cost required for the removal of the weld cap. Removing the weld cap can, in some cases, facilitate more precisely aligning subsequent layers with the base or a previous layer compared to cases where the weld cap is not removed.

[0080] While the steps of the exemplary method 352 have been described in connection with securing the first layer of wrap onto the base, it should be recognized that any one or more of the various different steps of the exemplary method 352 can be repeated as necessary to add additional layers of wrap to the base. However, it should be recognized that by repeating the steps to place a layer after the first layer, each subsequent layer can be wound onto the preceding layer in the stack of layers, and each layer can form a helical seam that is different from the helical seam formed by the preceding layer.

[0081] A specific system and method for forming the tubular structure 104 (FIGS. 1A-1D) based on such a layer that is pre-curved before being placed onto the base, and a method for operating such a system have been described. Here, interest is directed to the description of a system and method for forming the tubular structure 104 (FIGS. 1A-1D) using tension to conform a material material in a curved form to a curved surface.

[0082] Now referring to FIGS. 4A and 4B, the system 460 can include one or more examples of a tension roller 462, a rotator 464, a guiding system 466, and a joining device 468. Each example of the tension roller 462 can be arranged to contact the planar form of the material material 469 as the planar form of the material material 469 moves in the supply direction "F" so as to apply tension to the planar form of the material material 469. The rotator 464 can be operable to rotate a curved surface, such as the second surface 112, of the base 106 about the longitudinal axis "L". The material material 469 can be attached directly or indirectly to the curved surface of the base 106 such that as the rotator 464 rotates the curved surface of the base 106 in a direction away from one or more examples of the tension roller 462, the rotation of the base 106 pulls the planar form of the material material 469 from the material source 470 towards the base 106 in the supply direction "F". If the curved surface of the base 106 continues to rotate, the planar form of the material material 469 can be pulled onto the curved surface of the base 106 and bent along the first helical seam 118a to form the first layer 116a.

[0083] To form the first layer 116a (and position it along the helical seam associated with the subsequent layer), the accurate positioning of the stock material 469 along the first helical seam 118a can be advantageously achieved through a combination of the shape of the stock material 469 in planar form and the operation of the guiding system 466. That is, the stock material 469 in planar form from the stock source 470 can include a plurality of plates in a non-linear butting engagement with each other according to any one or more of a variety of different techniques. In particular, unless otherwise specified or apparent from the context, the stock material 469 in planar form and any other stock material described herein (e.g., the stock material 239 in FIG. 2B) can include a plurality of plates in a non-linear butting engagement with each other according to the technique for arranging linearly edge-bonded plates of material relative to each other to form a helical seam, as described in U.S. Patent No. 9,302,303, entitled "TAPERED STRUCTURE CONSTRUCTION," issued to Smith et al. on April 5, 2016, the entire content of which is incorporated herein by reference. Further, between one or more examples of the tension rollers 462 and the base 106, the guiding system 466 can adjust the position of the stock material 469 so that the stock material 469 is wound along the first helical seam 118a.

[0084] Following the rotation of the curved surface of the base 106 to form the first layer 116a, it should be recognized that a similar rotation of the curved surface of the base 106 about the longitudinal axis "L" can form subsequent layers by pulling the stock material 469 in planar form onto the first layer 116a. This process can be repeated as necessary to form a wrap including a predetermined number and position of layers to achieve a thickness profile according to the design specifications. In particular, the resulting tight fit by pulling the stock material 469 in planar form onto the curved surface of the base 106 or onto a preceding layer of material can be useful for improving the structural quality of the tubular structure being formed.

[0085] In general, one or more examples of the tension roller 462 can be operable to move perpendicular to the major surface of the material material 469 in planar form to increase or decrease the tension of the material material 469 in planar form when one or more examples of the tension roller 462 may be useful for controlling the positioning of the material material 469 along the helical seam. Further or alternatively, the tension of the material material 469 in planar form moving in the supply direction "F" can be adjusted by controlling the resistance to rotation of the tension roller 462. One or more examples of the tension roller 462 can define a gap through which the material material 469 in planar form can pass, and the position of one or more examples of the tension roller 462 can be controllable to move the gap in a direction perpendicular to the supply direction "F". Further or alternatively, each example of the tension roller 462 can be rotatable about an axis at least perpendicular to the supply direction "F".

[0086] The rotator 464 can include, for example, one or more rollers drivable to rotate the base 106 about the longitudinal axis "L" at a controlled speed. Further or instead, at least a portion of the rotator 464 can support the base 106 as the base 106 rotates to wind the material material 469 along the helical seam. For example, the rotator 464 can support at least each end of the base 106.

[0087] The guiding system 466 can include an actuator 471 that is controllable to wrap a planar stock material 469 along a helical seam extending around the longitudinal axis "L" of the base 106. The actuator 471 can be useful, for example, for achieving fine adjustment of the stock material 469 to position the longitudinal edges of the stock material 469 adjacent to each other so as to form a helical seam when the stock material 469 is wrapped onto the base 106 through rotation of the base 106, so that the position of the planar stock material 469 can be controlled in a direction perpendicular to the supply direction "F". The actuator 471 can include, for example, one or more edge guides, one or more edge rollers, one or more pinch rollers, or combinations thereof.

[0088] Additionally or alternatively, the guiding system 466 can include a sensor 472 operable to detect a parameter indicative of the position of the planar stock material 469. The actuator 471 can be adjustable based on a signal from the sensor 472 to adjust the position of the planar stock material 469 when a tubular structure is being formed. For example, the sensor 472 can detect the position of the planar stock material 469 at a position immediately prior to the stock material 469 being wrapped along the helical seam. Additionally or alternatively, the sensor 472 can detect the position of the stock material 469 (e.g., the longitudinal edge of the stock material 469) along the helical seam formed by the stock material 469. The sensor 472 can include, for example, an optical sensor, a camera as part of a machine vision system, a contact sensor, or combinations thereof.

[0089] Generally, the joining device 468 can mechanically couple the material material 469 to itself and / or to the base 106 according to any one or more of the various different techniques described herein. Thus, the joining device 468 can include a welding machine operable to form any one or more of the various different welds described herein. For example, with respect to fixing the material material 469 to the base 106, the joining device 468 can form the weld 120b (FIG. 1D). It should be recognized that the joining device 468 can similarly form other welds associated with the addition of subsequent layers, as needed, to form a wrap on the base 106 to achieve a tubular structure having a predetermined strength profile.

[0090] One or more aspects regarding the operation of the system 460 can be performed through manual operation by an operator, but the system 460 can include a control system 473 in some embodiments to facilitate accurate and repeatable control of certain aspects of the operation of the system 460. The control system 473 can include, for example, a processing unit 474 and a storage medium 475 that communicates with the processing unit 474. The processing unit 474 can include one or more processors, and the storage medium 475 can include a persistent computer-readable storage medium. The storage medium 475 can 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 regarding the manufacture of a tubular structure using the system 460. Optionally, the control system 473 can include an input device (e.g., a keyboard, a mouse, and / or a graphical user interface) that communicates with the processing unit 474 and the storage medium 475, and when the processing unit 474 executes one or more of the manufacturing methods described herein, the processing unit 474 is further or alternatively adapted to respond to inputs received via the input device.

[0091] FIG. 5 is a flow diagram of an exemplary method 576 of forming a tubular structure. Unless otherwise specified or apparent from the context, any one or more aspects of the exemplary method 576 may be embodied as computer-readable instructions stored in a memory medium 475 (FIG. 4A) and executable by a processing unit 474 (FIG. 4A) of a control system 473 (FIG. 4A) to operate the system 460 (FIG. 4A) to form the tubular structure 104 described in connection with FIGS. 1A-1D.

[0092] As shown at step 577, the exemplary method 576 can include joining (e.g., welding) a plurality of plates (e.g., trapezoid-shaped metal plates) in abutting engagement with each other to produce a material in planar form. In this regard, it should be understood that the abutting joint includes joining the short edges of one plate to the short edges of the other plate together to form a seam perpendicular to the parallel long edges of each plate. Such joining can include, for example, welding the plates to each other according to any one or more of the various different welding techniques described herein. As described above, the non-linear abutting engagement of the plurality of plates can include a geometric arrangement in which the linear edges (e.g., parallel linear edges) can be bent such that a helical seam is formed. In a particular embodiment, the plurality of plates can be joined in a non-linear abutting engagement with each other such that the longitudinal edges of each plate are perpendicular to the longitudinal edges of at least one other plate. Additionally or alternatively, the plurality of plates can be joined in a linear abutting engagement with each other such that the longitudinal edges of each plate are collinear with the respective longitudinal edges of the other plates. Additionally or alternatively, in an example where the tubular structure being formed is a right circular cylinder, a single plate can be used as the material in planar form.

[0093] As shown in step 578, exemplary method 576 can include securing a stock material to a curved surface of a base that defines a longitudinal axis. Since tension is applied to the stock material, it is generally desirable to use one or more techniques to permanently secure the stock material to the curved surface to reduce the possibility that the stock material will be inadvertently detached from the curved surface. For example, the stock material can be secured to the curved surface of the base using one or more of the welding techniques described herein.

[0094] As shown in step 579, exemplary method 576 can include rotating the curved surface of the base about the longitudinal axis of the base. With respect to the stock material secured to the base (e.g., directly or indirectly secured to the curved surface of the base), it should be recognized that rotation of the curved surface of the base can bend the stock material in a planar form about the curved surface of the base. That is, the stock material can be bent about the curved surface of the base such that the stock material and the base together form at least a portion of the tubular structure being formed. In the case of the first layer, the stock material in a planar form that bends about the curved surface of the base can be adapted to the curved surface of the base directly. Additionally or alternatively, with respect to subsequent layers, the stock material in a planar form that bends about the curved surface of the base can be adapted to the stock material of a preceding layer secured to the base directly. In a particular embodiment, by controlling the position of the stock material as it is bent about the curved surface of the base, the first longitudinal edge and the second longitudinal edge of the stock material can form a helical seam about the longitudinal axis of the base such that the stock material and the base together form at least a portion of the tubular structure being formed.

[0095] As shown in step 580, exemplary method 576 can include moving a planar form of the material through one or more tension rollers along with the material fixed to the base as the curved surface of the base rotates about the longitudinal axis. The one or more tension rollers can be adjustable to adjust the amount of tension in the planar form of the material, for example, to facilitate achieving a tight fit of the material moving on the curved surface of the base.

[0096] As shown in step 581, exemplary method 576 can include joining the material to itself along at least one helical seam. For example, joining the material to itself along at least one helical seam can include welding the material to itself to form a weld having the same spread as the helical seam. Further or alternatively, joining the material to itself along at least one helical seam can include joining the material to the curved surface of the base, to a previous layer of the material, or a combination thereof.

[0097] In general, unless otherwise specified or apparent from the context, it should be appreciated that any one or more of the various different steps of exemplary method 576 can be repeated as necessary to wind multiple layers on top of each other in any number and geometric arrangement of layers useful for forming a tubular structure having a predetermined strength profile.

[0098] Although specific embodiments have been described, other embodiments are possible additionally or alternatively.

[0099] For example, while the material in planar form has been described as being wound onto a base to form a tubular structure, it should be recognized that the material in planar form can further or alternatively be wound onto a reusable mandrel instead of the base that forms part of the final tubular structure. Continuing with this example, the process of adding material can be repeated until the tubular structure is formed, with wraps including the number and arrangement of layers as necessary to achieve a predetermined strength profile of the tubular structure, using the first layer (formed on the mandrel) as the base.

[0100] As another example, while a reinforced tubular structure has been described as including a base and one or more layers wound around the base to provide an increased thickness (and hence strength) relative to the base, other approaches to the reinforced tubular structure are further or alternatively possible. For example, as described in the following examples, the tubular structure can include stabilizers disposed between a plurality of shells to provide an overall strength to the tubular structure.

[0101] Now, referring to FIGS. 6A and 6B, the tubular structure 682 can include a first shell 683, a second shell 684, and a filling material 685. The second shell 684 can have a frustoconical shape, and the first shell 683 can be nested within the second shell 684 such that the first shell 683 and the second shell 684 define a gap therebetween. The filling material 685 can be disposed within the gap defined between the first shell 683 and the second shell 684. For example, the filling material 685 can fill the gap so as to be useful for achieving uniform strength characteristics in the tubular structure 682. In particular, the filling material 685 can facilitate transferring (transmitting) stress (e.g., shear stress) between the first shell 683 and the second shell 684. Further or alternatively, the filling material 685 disposed in the gap defined by the first shell 683 and the second shell 684 can reduce the likelihood of the first shell 683 and the second shell 684 bending under a given load compared to the likelihood of the first shell 683 and the second shell 684 bending without the filling material 685 between the first shell 683 and the second shell 684 under the same load. That is, the tubular structure 682 can achieve strength and rigidity comparable to that of a tubular structure formed of a thick, non-hollow metal wall. However, the first shell 683 and the second shell 684 can have thin metal walls compared to a tubular structure formed of a thick, non-hollow metal wall, and the strength performance of the tubular structure 682 can generally be achieved at a significantly lower cost and with a significantly shorter production time compared to forming a tubular structure that achieves the same strength performance using a thick, non-hollow metal wall.

[0102] Generally, one or both of the first shell 683 or the second shell 684 can be formed using a helical formation of the material of the elongated piece. In some cases, the first shell 683 and the second shell 684 can be positioned concentrically with respect to each other such that a gap defined between the first shell 683 and the second shell 684 is substantially symmetric with respect to a central axis "C" defined by the first shell 683 and the second shell 684. Among other things, such symmetry can generally be useful for forming the tubular structure 682 with a substantially uniform strength circumferentially around the frustoconical shape of the second shell 684. In some cases, the second shell 684 can surround the first shell 683 such that the gap formed by the first shell 683 and the second shell 684 is annular, in which case such an annulus is useful for accommodating a filling material 685 between the first shell 683 and the second shell 684 and for isolating from external conditions. As a more specific example, the first shell 683 can be substantially parallel to the second shell 684 along a longitudinal axis (e.g., central axis "C") defined by the first shell 683. That is, the first shell 683 can have a frustoconical shape parallel to the frustoconical shape of the second shell 684 such that the gap between the first shell 683 and the second shell 684 is also frustoconical. Similar to other frustoconical shapes described herein, the frustoconical shape of the gap between the first shell 683 and the second shell 684 can be useful for achieving strength performance with less material and ultimately at a lower cost.

[0103] The filling material 685 can include, for example, a material bonded (adhered) to the first shell 683, the second shell 684, or a combination thereof. The filling material can include any one or more of a variety of different types of materials that have the desired strength characteristics for a given end-use application and that can be bonded (adhered) to metal. As an example, the filling material can include a material that has consistent strength characteristics throughout the volume of the filling material. Some examples of materials useful for the filling material include cement, filled epoxy resin, grout, high-density foam, sand, or a combination thereof. In some cases, the filling material can include a plurality of components that are spatially separated from each other with such a spatial separation of components useful for achieving a targeted strength profile in a longitudinal direction parallel to the central axis "C". Continuing with this example, the components of such a filling material can include different concrete formulations arranged in layers in a direction parallel to the central axis "C".

[0104] Now, referring to FIGS. 7A - 7C, the tubular structure 787 can include a first shell 788, a second shell 789, and a plurality of structural elements 790 (e.g., steel bars, ribs, tubes, or combinations thereof). Unless otherwise specified or apparent from the context, the first shell 788 and the second shell 789 can be arranged relative to each other in a manner similar to any one or more of the configurations of the first shell 683 and the second shell 684 described above in connection with FIGS. 6A - 6B. Thus, for example, the second shell 789 can have a frustoconical shape, and the first shell 788 can be nested within the second shell 789 such that a gap 791 is defined between the first shell 788 and the second shell 789. The plurality of structural elements 790 can be coupled to each of the first shell 788 and the second shell 789 and can extend through the gap 791. Through such coupling, each of the plurality of structural elements 790 can facilitate transferring shear loads and / or reducing the likelihood of bending of each shell. More specifically, with the plurality of structural elements 790 coupling the first shell 788 and the second shell 789, the tubular structure 787 can achieve structural performance similar to that of a tubular structure formed of a thick and non - hollow metal wall. Thus, similar to other examples described herein, the annular structure 787 can easily achieve structural performance comparable to that of a tubular structure formed of a thick and non - hollow metal wall while significantly reducing the cost of fabrication.

[0105] 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 that are 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 that it is useful for attaching the structural element 790 within the gap 791 and / or replacing a structural element within the gap 791 without the need to access the gap 791. For example, each of the plurality of structural elements 790 can pass through the plurality of first holes 792 and reach the plurality of second holes 793, and the first shell 788 and the second shell 789 can be joined to each other. Further 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 so as to stiffen the tubular structure 787 compared to the rigidity of only the first shell 788 and the second shell 789.

[0106] Although a particular embodiment of the reinforced tubular structure has been described as including a stabilizer disposed between the shells, it should be recognized that the stabilizer can further or alternatively be disposed along the outer surface of the shell to form a tubular structure that is less expensive and faster to fabricate compared to a tubular structure formed from a thick, non-hollow metal wall, while having structural performance comparable to that of a tubular structure formed from a thick, non-hollow metal wall.

[0107] For example, referring now to FIGS. 8A - 8C, the tubular structure 880 can include a shell 888 and a plurality of elongated ribs 889. The shell 888 can have a first surface 891 and a second surface 892 that face each other, and the first surface 891 can define a cavity 893. The shell 888 can have a tubular shape (e.g., a frustoconical shape) that defines a longitudinal axis "L". The shell 888 can have a helical seam 894 that extends around the longitudinal axis "L", and each of the plurality of elongated ribs 889 can be coupled to the shell 888 (e.g., along one or both of the first surface 891 or the second surface 892) such that the longitudinal dimension of each elongated rib 889 extends across the helical seam 894 of the shell 888 and is in a plane substantially the same as the longitudinal axis "L" to provide structural support across the helical seam 894. In certain embodiments, each of the elongated ribs 889 can be notched to facilitate passing through the helical seam 894 of the shell 888 underlying the plurality of elongated ribs 889 while reducing the potential to interfere with a tight fit between each of the plurality of elongated ribs 889 and the shell 888.

[0108] The plurality of elongated ribs 889 can be spaced from each other along the shell 888 according to any spacing that can be useful to achieve a targeted structural performance. For example, the plurality of elongated ribs 889 can be coupled to each other along a plurality of longitudinal seams 895 that are in a plane substantially the same as 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 coupled to each other so as to surround the shell 888 such that they can be useful to achieve substantially uniform strength around the circumference of the shell 888. The plurality of elongated ribs 889 can be coupled to the shell 888 using any one or more of a variety of different techniques, but the longitudinal seams 895 can be formed, in some embodiments, by welding the plurality of elongated ribs 889 to the shell 888 using full welding or skip welding.

[0109] In certain embodiments, each of the elongated ribs 889 can be V-shaped with the first leg 896 and the second leg 897 joined to each other at the apex 898, and the first leg 896 and the second leg 897 are joined to the shell 888 such that the apex 898 faces radially away from the shell 888. Continuing with this example, the elongated ribs 889 can be formed into a V-shape using a press brake. Additionally or alternatively, the elongated ribs 889 can be roll formed or formed from a pair of flat strips (elongated pieces) of material that are joined (e.g., welded) to each other at the apex 898.

[0110] The above-described systems, devices, methods, processes, etc. can be implemented in hardware, software, or any combination thereof suitable for 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, along with internal memory and / or external memory. Alternatively or instead, this can include one or more application-specific integrated circuits, programmable gate arrays, programmable array logic components, or any other device(s) that can be configured to process electronic signals. As further recognized, the implementation of the above-described processing or devices can include 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 language (including assembly language, hardware description language, and database programming languages and techniques), which is stored, compiled, or interpreted for execution in a combination of one of the above devices, across different processor environments, processor architectures, or combinations of different hardware and software. At the same time, the processing can be distributed across devices such as the various systems described above, or all of the functionality can be integrated into a dedicated stand-alone device. All such substitutions and combinations are intended to fall within the scope of the present disclosure.

[0111] Embodiments disclosed herein can include a computer program product including computer-executable code or computer-usable code for performing any and / or all steps of the control systems described above when executed on one or more computing devices. The code can be stored in a persistent manner in a computer memory, which can be the memory in which the program is executed (e.g., random access memory associated with a processor), or a storage device such as a disk drive, flash memory, or any other optical, electromagnetic, magnetic, infrared, or other device or combination of devices. In another aspect, any of the control systems described above can be embodied in any suitable transmission medium or propagation medium for transmitting computer-executable code, and / or any input or output from such transmission medium or propagation medium.

[0112] The steps of the methods of the embodiments described herein are intended to include any suitable way of causing such steps of the method to be performed that is consistent with the patentability of the following claims, unless a different meaning is clearly provided or apparent from the context. Thus, for example, performing step X can include any suitable way of causing step X to be performed by another party such as a remote user, a remote processing resource (e.g., a server or cloud computer), or a machine. Similarly, performing steps X, Y, and Z can include any way of managing or controlling any combination of such other individuals or resources for performing steps X, Y, and Z in order to obtain the benefits of such steps. Thus, the steps of the methods of the embodiments described herein are intended to include any suitable way of causing such steps to be performed by one or more other parties or entities that is consistent with the patentability of the following claims, unless a different meaning is clearly provided or apparent from the context. Such parties or entities need not be under the management or control of any other party or entity and need not be located within a particular jurisdiction.

[0113] As will be appreciated, the methods and systems described above are presented by way of example and not limitation. Many variations, additions, omissions, and other changes will be apparent to those skilled in the art. Further, the order and presentation of the steps of the methods in the above description and drawings are not intended to require this order of performing the recited steps unless a particular order is clearly required or apparent from the context. Thus, while particular embodiments have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications in form and detail can be made without departing from the spirit and scope of the present disclosure, and are intended to form a part of the present invention as broadly construed as legally permitted.

[0114] Exemplary embodiments consisting of various combinations of the components of the present invention are shown below. 1. A tubular structure comprising: a base having a first surface and a second surface facing each other, the first surface defining an elongated cavity and having a tubular shape defining a longitudinal axis extending along the elongated cavity; and a wrap supported on the second surface of the base, wherein the wrap includes at least one layer, each layer having a first longitudinal edge and a second longitudinal edge coupled to each other along individual helical seams associated with the given layer and extending around the longitudinal axis of the base, the tubular structure. 2. The tubular structure according to 1 above, wherein the combined thickness of the wrap and the base varies in a direction parallel to the longitudinal axis of the base. 3. The tubular structure according to 2 above, wherein the thickness of the wrap varies in a direction parallel to the longitudinal axis of the base. 4. The tubular structure according to 3 above, wherein the thickness of the base is substantially constant in a direction parallel to the longitudinal axis of the base. 5. The tubular structure according to 3 above, wherein the thickness of the wrap varies monotonically in a direction parallel to the longitudinal axis of the base. 6. The tubular shape of the base includes a frustum of a cone that tapers in a direction parallel to the longitudinal axis, and the thickness of the wrap monotonically decreases in the direction of the taper of the frustum of the cone. The tubular structure according to 5 above. 7. The at least one layer is a plurality of layers, and the plurality of layers are at least partially stacked on top of each other in the radial direction. The tubular structure according to 2 above. 8. Each layer of the plurality of layers surrounds the base at least once. The tubular structure according to 7 above. 9. The number of layers of the plurality of layers varies in a direction parallel to the longitudinal axis of the base. The tubular structure according to 7 above. 10. Each layer of the plurality of layers is joined to the base, to at least one other layer of the plurality of layers, or a combination thereof. The tubular structure according to 7 above. 11. Each layer of the plurality of layers is welded to the base, to another layer of the plurality of layers, or a combination thereof. The tubular structure according to 10 above. 12. The individual helical seams of a given layer are longitudinally offset from the individual helical seams of each layer adjacent to the given layer. The tubular structure according to 7 above. 13. The base includes a seam that extends around the longitudinal axis of the base. The tubular structure according to 1 above. 14. The individual helical seams of at least one layer of the wrap are longitudinally spaced from the seam of the base along the longitudinal axis. The tubular structure according to 13 above. 15. The seam of the base is parallel to the individual helical seams of at least one layer of the wrap. The tubular structure according to 13 above. 16. A system for forming a tubular structure, A drive system including a drive roll operable to move a planar form of a material in a supply direction, A bending device arranged to receive the planar form of the material moving in the supply direction and controllable to bend the planar form of the material to produce a curved form of the material. A plurality of support rollers operable to rotatably support a curved surface of a material; One or more pressure rollers arranged to receive the material material in the curved form from the bending device, wherein the one or more pressure rollers are movable to press the material material in the curved form from the bending device onto the curved surface of the material rotatably supported on the plurality of support rollers. A system. 17. The system according to item 16 above, further comprising a joining device arranged to join the material material in the curved form to itself, to a curved surface rotatably supported on the plurality of support rollers, or to a combination thereof. 18. The system according to item 16 above, further comprising a guiding system arranged to receive the material material in the curved form from the bending device, the guiding system including an actuator controllable to wind the material material in the curved form along individual helical seams of a given layer of a formed tubular structure. 19. The system according to item 18 above, wherein the actuator includes one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof. 20. The system according to item 18 above, wherein the guiding system further includes a sensor configured to detect a parameter indicating the position of the material material in the curved form along the individual helical seams, and the actuator is in electrical communication with the sensor and the actuator is adjustable based on a signal from the sensor to adjust the position of the material material in the curved form along the individual helical seams of a given layer of a formed tubular structure. 21. A method of forming a tubular structure, comprising: Bending a portion of a material material in a planar form into a material material in a curved form; Wrapping the material material in the curved form around a curved surface of a base to form a helical seam around a longitudinal axis defined by the base; Joining the material material in the curved form to at least itself along the helical seam. 22. The method according to 21 above, wherein winding the material material in the curved form on the curved surface of the base includes pressing the material material in the curved form against the curved surface of the base. 23. The method according to 21 above, wherein joining the material material in the curved form to at least itself along the spiral seam includes joining the material material in the curved form to the curved surface of the base. 24. The method according to 21 above, wherein joining the material material in the curved form to at least itself includes welding the material material in the curved form to itself along the spiral seam. 25. A system for forming a tubular structure, a tension roller that can be arranged in contact with the flat-form material material when the flat-form material material moves in the supply direction, a rotator operable to rotate the curved surface of the base about a longitudinal axis defined by the base, a guiding system including an actuator controllable to wind the flat-form material material along a spiral seam around the longitudinal axis of the base, a joining device arranged to join the material material to at least itself along the spiral seam when the tubular structure is being formed, the system. 26. The system according to 25 above, wherein the actuator includes one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof. 27. The system according to 25 above, wherein the guiding system further includes a sensor configured to detect a parameter indicating the position of the material material along the spiral seam, the actuator is in electrical communication with the sensor, and the actuator is adjustable based on a signal from the sensor to adjust the position of the flat-form material material along the spiral seam when the tubular structure is being formed. 28. A method of forming a tubular structure, joining a plurality of plates by non-linear butting engagement with each other to produce a flat-form material material. Fix the material on the curved surface of the base defining the longitudinal axis, including rotating the curved surface of the base about the longitudinal axis of the base with the material fixed to the base, and bending the planar material around the curved surface of the base while the first longitudinal edge and the second longitudinal edge of the material form at least one helical seam around the longitudinal axis of the base. A method. 29. The method according to 28 above, further comprising moving the planar material through one or more tension rollers while the material is fixed to the base and the curved surface of the base is rotating about the longitudinal axis. 30. The method according to 28 above, further comprising joining the material to itself along at least one helical seam. 31. Joining the material to itself along at least one helical seam further includes joining a layer of the material to the curved surface of the base, to a previous layer of the material, or a combination thereof. The method according to 30 above. 32. A tubular structure, a first shell, a second shell having a frustoconical shape, wherein the first shell is nested within the second shell with a gap defined between the first shell and the second shell, and a second shell, a stabilizer disposed within the gap, the stabilizer maintaining the positions of the first shell and the second shell relative to each other. A tubular structure. 33. The tubular structure according to 32 above, wherein the first shell is substantially parallel to the second shell along the longitudinal axis defined by the first shell. 34. The tubular structure according to 32 above, wherein the stabilizer includes a filling material coupled to the first shell, the second shell, or a combination thereof. 35. The tubular structure according to 32 above, wherein the stabilizer includes a plurality of structural elements that extend through the gap and are coupled to each of the first shell and the second shell. 36. The tubular structure according to 35 above, wherein the first shell defines a plurality of first holes, the second shell defines a plurality of second holes aligned with the plurality of first holes, and each of the plurality of structural elements extends through one of the plurality of first holes and a corresponding one of the plurality of second holes. 37. A tubular structure, a shell having a first surface and a second surface, wherein the first surface defines an elongated cavity, the first surface faces the second surface, the shell has a tubular shape defining a longitudinal axis extending along the elongated cavity, and has a helical seam extending around the longitudinal axis; a plurality of elongated ribs, wherein the plurality of elongated ribs are coupled to the shell with a longitudinal dimension of each elongated rib substantially parallel to the longitudinal axis defined by the tubular shape of the shell. 38. The tubular structure according to 37 above, wherein the tubular shape of the shell is frustoconical. 39. The tubular structure according to 37 above, wherein at least one of the plurality of elongated ribs is fixed along the first surface of the shell. 40. The tubular structure according to 37 above, wherein at least one of the plurality of elongated ribs is fixed along the second surface of the shell. 41. The tubular structure according to 37 above, wherein the plurality of elongated ribs are coupled to each other along a plurality of longitudinal seams in a plane substantially the same as the longitudinal axis defined by the tubular shape of the shell. 42. The tubular structure according to 37 above, wherein each of the plurality of elongated ribs is in a V shape in which a first leg and a second leg are joined to each other at a vertex, and the first leg and the second leg are coupled to the shell.

Claims

1. 1. A system for forming a tubular structure, comprising: a drive system including a drive roll operable to move the blank material in a planar form in a feed direction; a bending device disposed to receive the blank material in planar form moving in the feed direction and controllable to bend the blank material in planar form to produce a curved form; a plurality of support rollers operable to rotatably support a curved surface of the material; one or more pressure rolls positioned to receive the curved form of the blank material from the bending device, the one or more pressure rolls being movable to press the curved form of the blank material from the bending device onto a curved surface of the material rotatably supported on the plurality of support rollers.

2. 10. The system of claim 1, further comprising a bonding device positioned to bond the curved form of blank material to itself, to a curved surface rotatably supported on the plurality of support rollers, or to a combination thereof.

3. 10. The system of claim 1, further comprising a guide system disposed to receive the curved form of the blank material from the bending apparatus, the guide system including an actuator controllable to wrap the curved form of the blank material along an individual helical seam of a given layer of the tubular structure being formed.

4. The system of claim 3 , wherein the actuator comprises one or more edge guides, one or more edge rollers, one or more pinch rollers, or a combination thereof.

5. 4. The system of claim 3, wherein the guidance system further includes a sensor configured to detect a parameter indicative of a position of the curved form of blank material along each of the spiral seams, the actuator being in electrical communication with the sensor, the actuator being adjustable based on a signal from the sensor to adjust a position of the curved form of blank material along each of the spiral seams of a given layer of the tubular structure being formed.

6. 1. A method of forming a tubular structure, comprising: Bending a portion of the blank material in a flat strip form into a curved form; wrapping the curved form of blank material over a curved surface of the base to form a helical seam about a longitudinal axis defined by the base; joining the curved form of blank material at least to itself along the helical seam.

7. The method of claim 6 , wherein wrapping the curved form of the blank material onto the curved surface of the base comprises pressing the curved form of the blank material onto the curved surface of the base.

8. 7. The method of claim 6, wherein joining the curved form of blank material to at least itself along the spiral seam comprises joining the curved form of blank material to a curved surface of the base.

9. 7. The method of claim 6, wherein joining the curved form of the blank material at least to itself comprises welding the curved form of the blank material to itself along the helical seam.

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