Patent Application
20130052396
This disclosure relates generally to honeycomb structures and more specifically to curved honeycomb core structures manufactured using minimal forming stresses, processes and equipment.
Honeycomb structures, also referred to herein as “honeycomb core,” “core material” or simply “core,” typically comprise a plurality of abutting rectangular or hexagonal cells shaped to a desired form. Honeycomb structures are often used as structural support for their high strength to weight ratio due to the low density of the honeycomb formation.
Honeycomb structures are typically manufactured from a thin, flat base material such as metal or paper. The flat base material is cut into narrow, elongated strips or ribbons, which are folded or bent into contoured strips of semi-hexagonal peaks and troughs. For example, an elongated strip of a material may be scored at regularly spaced intervals. To form regular hexagonally shaped cells, the score lines would be parallel to the ends of the strip and the material would be folded along the score lines to an angle of 60° twice in one direction and then twice in the opposite direction, and continuously alternating in that fashion.
The resulting folded strips are then joined together by adhesive, spot welding, brazing or other known joining methods to form a structure having a series of hexagonally shaped cells, thereby forming a flat honeycomb core structure. Although cells in a honeycomb core structure are typically hexagonal, honeycomb core structures may also be formed from cells having non-hexagonal shapes.
The resulting honeycomb core structure, which consists of a flat core structure having cells with walls oriented in a direction perpendicular to the flat surface of the core structure, is able to sustain large loads in a direction parallel to the walls of the honeycomb cells, while being lightweight due to an absence of material within the cells.
In many applications, it is desirable to form a honeycomb structure that does not have a flat contour, but is contoured to some other shape. Various methodologies and apparatuses have been developed for shaping honeycomb core to particular contours.
Some methods for forming contoured honeycomb structures begin with a pre-formed flat honeycomb core and then mold or form the flat core into a desired shape.
For example, one method of producing a contour consisting of short angle bends in a honeycomb structure consists of first manufacturing a flat honeycomb core material. A force is applied to cells of the flat honeycomb structure to deform or collapse the honeycomb cells in the area in which the short angle bend is desired. This results in a honeycomb structure having a short radius bend area possessing cells with a height similar to the height of cells in the non-collapsed area.
Other methods of contouring core material consist of passing a preformed, flat honeycomb core material through a series of rollers that deforms the hexagonal cells and allows them to be bent in different directions.
Still further methods of forming core material into a desired shape consist of beginning with a flat core material and forcing the core material against and into a die having the required contour.
All of the foregoing methodologies require the application of force to a flat honeycomb structure in order to form it into a desired shape, which may lead to undesirable stresses in the honeycomb structure, and the strength and stiffness of the core are sacrificed due to the fact that the honeycomb cell walls are no longer normal to the surface of the core.
Other methods generally avoid bending or folding a fully assembled honeycomb core material. Instead, these methods begin by forming flat, rectangular strips having a plurality of sections along the length of the strips, the sections being separated by fold lines. The strips are folded at the fold lines and joined together to form a desired honeycomb contour shape without additional application of force to the honeycomb core.
For example, some methods contemplate the formation of a honeycomb structure having hexagonally shaped cells wherein some cell walls possess a tapering V-shaped crimp. By placing all crimped edges on one side of the honeycomb structure, and all non-crimped edges on the opposite side of the honeycomb structure, the crimped side is made to be shorter than the non-crimped side. This facilitates variation in the radii of curvature of the honeycomb structure, which leads to a curved core material.
Other methods contemplate forming rectangular strips wherein the fold lines are placed along the length of the strips, such that the sections between the fold lines are not regularly shaped. Fold lines are placed in the strips such that when folded, the entire edges of the strips form an overall curved structure. When the folded strips are adhered together, the resulting core material has a desired contour. For example, Japanese Laid-Open Patent Publication No. 58-25531 and U.S. Pat. No. 5,270,095 disclose strips having some fold lines perpendicular to the length of the strip and other fold lines that are slanted in relation to the length of the strip. In a flat or unfolded state, the edges of the strip are straight and form a rectangle. In a folded state, the slanted fold lines create a folded strip with straight edges that form an overall curved structure determined by the angle of the slant in the fold lines. However, this process has limited utilization in that it can be used to manufacture honeycomb core having only a single shape.
What is needed is a simplified method of manufacturing contoured honeycomb structures that does not introduce undesired stresses or sacrifice strength and stiffness of the structure, and permits formation of contoured honeycomb core in a wide variety of shapes and sizes with minimal forming steps to provide manufacturing cost and time efficiencies.
The foregoing purposes, as well as others that will be apparent, are achieved generally by providing a ribbon for manufacturing a honeycomb structure having a plurality of honeycomb cells, an inner core surface, an outer core surface, and a curved core surface geometry. The ribbon comprise a ribbon top edge, a ribbon bottom edge and a continuous series of foldable sections arranged in sequence along the length of the ribbon, the ribbon top edge and the ribbon bottom edge being curved along the length of the ribbon when the ribbon is in a flat, unfolded state. Alternatively, each of the foldable sections has a top edge and a bottom edge, and the top edge or bottom edge of at least one section in the continuous series of foldable sections is curved to match the curved geometry of said honeycomb structure.
In another aspect of this disclosure, a honeycomb structure having a plurality of honeycomb cells, an inner core surface, an outer core surface and a curved core surface geometry is provided. The honeycomb structure comprises a plurality of ribbons aligned in the direction of a ribbon orientation and folded to form a continuous series of half-cells, each half-cell having a shape approximately equivalent to half of the shape of a honeycomb cell in said plurality of honeycomb cells. The ribbons are lined up side-by-side to form a plurality of honeycomb cells in the desired shape without additional forming steps or stresses. The ribbons comprise one or both of the ribbon structures identified above.
In yet another aspect of this disclosure, a method of manufacturing a curved honeycomb structure is provided, comprising determining an inner surface shape for an inner surface of the curved honeycomb structure and an outer surface shape for an outer surface of the curved honeycomb structure, determining a honeycomb cell shape for a plurality of honeycomb cells, determining a plurality of ribbon shapes of each of a plurality of ribbons for forming said plurality of honeycomb cells, cutting a plurality of ribbons from a base material, the ribbons having the determined shapes, aligning said plurality of ribbons side-to-side and joining adjacent ribbons together to facilitate creation of the curved honeycomb structure from said plurality of ribbons.
In yet another aspect of this disclosure, a honeycomb structure having a cylindrical shape with an axis, an inner radius, an outer radius, an inner cylindrical surface, an outer cylindrical surface and a thickness is provided, comprising a plurality of ribbons arranged side by side, each ribbon having an inner edge and an outer edge, both running along a length of the ribbon, and comprising a continuous series of alternating rectangular sections and trapezoidal sections along the length of the ribbon, said trapezoidal sections having an elliptical top edge at the outer edge of the ribbon, and an elliptical bottom edge at the inner edge of the ribbon, the ribbon being bent along borders between the rectangular and trapezoidal sections to form a series of semi-hexagonal shapes, the rectangular sections of adjacent ribbons being joined together to form the cylindrical shape of the honeycomb structure.
In yet another aspect of this disclosure, a method of manufacturing a honeycomb structure having a cylindrical shape is provided, comprising providing a plurality of ribbons, each ribbon having an inner edge and an outer edge, both running along a length of the ribbon, and comprising a continuous series of alternating rectangular sections and trapezoidal sections along the length of the ribbon, said trapezoidal sections having an elliptical top edge at the outer edge of the ribbon, and an elliptical bottom edge at the inner edge of the ribbon, the ribbon being bent along borders between the rectangular and trapezoidal sections to form a series of semi-hexagonal shapes, arranging said ribbons side by side, and joining the rectangular sections of adjacent ribbons together to form said cylindrical shape of the honeycomb structure.
Other objects, features and advantages will be apparent when the detailed description of the preferred embodiments is considered in conjunction with the drawings.
Reference will now be made to the drawings, in which similar elements in different drawings bear the same reference numerals.
The following disclosure describes improved methods and materials for manufacturing a curved honeycomb core having a desired geometrical shape from a plurality of ribbons with minimal forming steps and stresses, including methods for determining preferred ribbon geometries for manufacturing a curved honeycomb core having a desired shape. It will be understood by those skilled in the art that the principles of the methods and materials disclosed herein may be applied to form a wide variety of ribbon geometries and, thus, honeycomb core structures having a wide variety of geometrical shapes. As used herein, the terms “geometry” or “geometries” or “geometrical”, when referring to ribbons means the shape and size of the ribbon, placement of fold lines in the ribbon and the structure of the ribbon edges (e.g., straight edge or curved edge), and when referring to honeycomb core, means the shape and size of the core, the shape and size of cells within the core and the structure of the core's inner and outer surfaces (e.g., curved or straight) and the core's axis.
For example, and without limitation, the principles disclosed herein may be applied to form honeycomb core having desired curved, geometrical shapes including any radial portion of (such as a “semi-cylindrical” tube having a semi-circular cross-section) or the whole of a cylinder having an arbitrary curvature. Generally, cylindrical shapes have a central axis, and outer and inner surfaces, which together define a thickness. Both the thickness and the axis may vary from point to point on the cylinder. In other words, the axis of the cylindrical shape may have curvature that changes along its length and the thickness of the cylindrical shape may vary as well. The cross-sectional shape of the cylinder, taken by a plane having a normal parallel to the axis of the cylinder, may also vary along the length of the axis, and may have varying eccentricity, radii, and other parameters. Therefore, as used herein, the terms “cylinder” or “cylindrical” are not limited to a regular cylinder having a straight axis and a constant circular cross-section, but can refer to any of a variety of tubular geometries having a varying cross-section surrounding a straight or curved axis including, for example, a curved radome, a cone shape or other cylindrical shapes. The terms “cylinder” or “cylindrical” and “tube” or “tubular” may be used interchangeably throughout this specification. It will be appreciated that variations in the geometry, composition and construction of such honeycomb core can be adapted depending on their intended use in accordance with the teachings of this disclosure.
An example honeycomb core 100 made using the principles of this disclosure is shown in
Each of the abutting cells 102 comprises a plurality of walls, including node walls and non-node walls, and top and bottom hexagonally shaped faces corresponding to the outer and inner surfaces of the core, respectively. Node walls 114 are walls that provide surfaces for two adjacent ribbons 200 to be joined together, as shown in
A close-up of a specific example of a ribbon geometry 496 that may be used to form the regular cylinder honeycomb core shown in
As described above, these section shapes may vary depending on the desired geometry of the honeycomb core. It should be understood that the geometry of the ribbon is defined by the shape of these sections. For example, the geometry of the ribbon 496 in
In addition to being defined by the geometry of the honeycomb core 100, the geometry of the ribbon 496 is also defined by the shape of the cells 102. In
A common feature among ribbons having different geometries that are formed in accordance with the principles in this disclosure is that the edges of each of the sections of the ribbons are designed to exactly or very nearly match the shape of the portion of the honeycomb core which it forms. For the example ribbon depicted in
The shapes of various objects discussed herein may be determined using geometrical principles. Some of the geometrical determinations may be made using basic mathematical principles. However, for complex shapes, while basic mathematical principles may be used, it is considered more practical to determine the shapes of such objects using numerical methods. As one of the most powerful tools for using numerical methods to determine complex geometrical shapes is 3D CAD software, some of the disclosure provided herein will make reference to operations conducted on such software. Virtually any 3D CAD software package capable of performing such operations or equivalents should be suitable to the task of making the geometrical determinations disclosed herein. One such software package is CATIA from Dassault Systèmes of Vélizy-Villacoublay, France.
A procedure for manufacturing a honeycomb core with a desired curved geometry will now be described with reference to
A general process for forming a honeycomb core is described in
In step 150, the shapes of outer and inner surfaces of a honeycomb core to be constructed are selected. These surfaces represent outer and inner walls of the final product that will be manufactured using the methodologies of this disclosure. A desired tubular shape is therefore provided in the form of mathematical parameterizations, or 3D CAD computer models, for an inner and outer surface of the desired tubular shape. It should be understood that this tubular shape may be any of a wide variety of curved cylindrical geometries.
In step 151, a ribbon orientation is selected. This is the direction along the honeycomb core at which ribbons will lie. The ribbon orientation relates to the shape of the cells of the honeycomb core as well as the geometries of the ribbons themselves. Preferably, a ribbon orientation should be selected such that the honeycomb core can be made using the smallest number of different ribbon geometries. It is desirable to use as few ribbon geometries as possible to provide cost and manufacturing time efficiencies. This can be done by determining a direction in which the cylinder has symmetry, and then selecting the ribbon orientation such that it is aligned with that symmetry. If this is optimally done, ribbons of identical geometry may be used to form the entire cylindrical core. This is described in further detail below, with respect to
In step 152, the shape, size and position of a pattern of cells that form the honeycomb core is determined. Each cell has inner and outer faces, which lie on the inner and outer surfaces of the cylindrical core, respectively. The shape of the cells may be pre-known or pre-determined. Alternatively, the shape of the cells may be determined using the procedures disclosed with reference to
Generally, it is beneficial for the cells 102 to be shaped and positioned such that they form a staggered series of interlocking cells 102, as shown for example in
In step 154, the geometry of the ribbons that comprise the cylindrical honeycomb core is determined based on the pattern of cells determined in step 152. The methodology for determining the geometry of these ribbons is described in more detail with reference to
It is contemplated that both steps 152 and 154, in which geometrical shapes of physical objects are determined, may be performed using mathematical principles, computer methods or some combination of both.
In step 156, flat ribbons are cut out of a desired material to the geometry specified in step 154.
In step 158, the cut ribbons are lined up side-by-side and adjacent ribbons are joined together at the node walls. The ribbons may be pre-folded prior to being joined together. Alternatively, the ribbons may be pre-stressed along fold-lines, joined together while flat prior to folding, and subsequently expanded to a desired shape. As used herein, “pre-stressed” means that ribbons are scored or pre-bent such that when an appropriate force is applied, the ribbons bend at the fold lines. By virtue of the geometry of the ribbons, a desired core geometry is formed. Alternatively, the ribbons need not be pre-stressed. Instead, when two ribbons are joined together, the portions of the ribbons which are joined together (i.e., the node-walls) are stronger and/or stiffer than the other portions of the ribbons. When a joined stack of ribbons is expanded, the non-joined portions bend while the joined portions stay substantially rigid. The expanded stack of ribbons will thus form the desired cell shapes. The process of lining up and joining the ribbons is explained in further detail below with respect to
Referring now to
In step 300, a desired geometry of a honeycomb structure to be manufactured is selected and is provided in the form of an outer surface and an inner surface of the desired shape. This geometry can be represented with a CAD model or a mathematical description of the geometry. The hollow cylindrical geometry 350 depicted in
The core geometry 350 depicted in
The shape of each of the cells is determined by selecting a “shape” for the cells in the form of a desired two-dimensional cross-section (for example, a hexagon) and taking a projection of the selected two-dimensional cross-section onto the inner and outer surfaces of the cylinder. As described above, cells are typically formed in the shape of a hexagon, but many other shapes may also be selected.
In step 302, a desired cross-section and distance from the cross-section to the axis of the cylinder are selected. This desired two-dimensional cross-section is oriented such that the cross-section is normal to the radius of the cylinder at the center of the cross-section.
If the axis 360 of the cylinder 350 has no curvature, then it is beneficial for at least two edges in the desired two-dimensional cross-section to be approximately parallel to each other, as this provides surfaces for adjacent ribbons to be adhered together. These two edges correspond to node walls in the cells. Similarly, if the axis 360 of the cylinder 350 has curvature, it is beneficial for two edges in the desired two-dimensional cross-section to be parallel to the radius of curvature of the axis, as this facilitates connection between adjacent ribbons oriented parallel to the radius of curvature of the axis of the cylinder. Again, these two edges correspond to node walls in the cells. The orientation of these two edges corresponds to a “ribbon orientation,” which is a direction along the surface of the core in which the ribbons will lie. These two edges should be roughly aligned with the ribbon orientation, so that these edges in adjacent ribbons will be parallel to each other.
In the example shown in
In step 304, the two-dimensional cross-section is projected onto the outer and inner surfaces of the cylinder to form outer and inner faces of a cell, respectively. The projection may be done by drawing lines from the vertices of the cross-section to the axis of the cylinder. Preferably, the lines are drawn down to two points on the axis. To do this, the vertices of the cross-section are divided into two groups separated by a line perpendicular to axis 360 and passing through the center 358 of the cross-section 356. These two groups are on opposite sides of the center 358 of the cross-section. Lines from each vertex in the same group are drawn to the same point on the axis, as shown in
In
In step 306, the vertices of the outer and inner faces are connected by edges to form the cell. The result is a cell shape and cell position for one cell of the honeycomb structure having thickness defined by the height of the walls of the cells. In
In step 308, cell shapes and positions are determined for a sufficient number of cells on the entire cylindrical honeycomb structure as desired. If the cylinder is sufficiently regular in shape (e.g., has a constant cross-section, constant axis curvature or zero axis curvature), a determined cell shape can be repeated through a portion of or through the entire cylinder. In that situation, cell shapes need to only be determined once, or a limited number of times. If the cylinder is not sufficiently regular, cell shapes may be determined for each point on the cylinder as necessary.
For example, with a regular cylinder having a straight axis and a constant circular cross-section, the shape of the cells will be the same at any point on the cylinder, since the geometry of the cylinder is completely uniform.
On the other hand, with a tapered cylinder (i.e., a truncated cone or a cone shaped cylinder), the cell shape may vary from one end of the tapered cylinder to the other. However, if the tapered cylinder has radial symmetry (e.g., it has a circular cross-section decreasing in radius from one end of the cylinder to the other), then a pattern of cells can be repeated around the axis of symmetry (i.e., identical patterns of cells exist in the direction of the axis). Any of these types of symmetries are useful in determining to what extent ribbon geometries are identical throughout the cylinder (and therefore for choosing a desired ribbon orientation). Sequences of cell shapes which are identical to each other (even though all cells within in each sequence may not have the same shape) allow the creation of identically shaped ribbons, shaped to correspond to the identical sequences of cell shapes. The ribbon orientation is preferably chosen such that the ribbons are in the same direction as the identical sequences of cell shapes.
If the axis of the cylinder is curved, then the shapes of the cells vary in a direction traveling around the axis of the cylinder. If the axis of the cylinder has a constant curvature, then a form of symmetry exists (rotated around the axis of curvature), and patterns of cells in the direction of that symmetry exist which are identical (e.g., for a torus, or a portion of a torus, identical patterns of cells exist for cells wrapped around the axis of the cylinder). Additional such symmetries may be determined and are relevant for determining appropriate ribbon geometry which is discussed in more detail below.
The computer model representation or mathematical representation of the cells in the cylinder is analyzed and “divided” to form at least one linear sequence of half-cells. The term “divided” refers to a mathematical or computer operation in which a defined geometry is “cut” by a surface such as a plane, to determine the shape of a portion of that defined geometry. The direction of the divide approximately follows the direction of the ribbon orientation. More specifically, the representation of cells in the cylinder is divided by a surface which runs adjacent to node walls of adjacent cells in the direction of the ribbon orientation. This surface is shaped to follow the ribbon orientation and to be adjacent to the node walls of the cells. Further, each surface alternately divides in half, and then runs adjacent to, the cells in the honeycomb core. To obtain a linear sequence of half-cells, in step 402, at least two such surfaces are provided—these two surfaces “enclose” a sequence of half-cells having alternating orientations. These dividing surfaces are also referred to herein as “dividing walls.”
In
In step 404, a linear sequence of half-cells is determined. This sequence is the result of performing a slicing operation (with, e.g., CAD software) on a model of the core with two adjacent dividing surfaces.
In
In step 406, the shape of each wall in the linear sequence of half-cells is determined. In
In step 407, the geometry of a flat ribbon is determined based on the wall shapes from step 406. This is described in more detail with respect to
In step 408, steps 402 through 407 are repeated as needed for each type of ribbon required to form the desired cylindrical geometry. In
Node wall 474 has a top edge 486, a bottom edge 487, and two side edges 490. Non-node walls 472, have two side edges 490, a top edge 488 and a bottom edge 489. The top edge 486 and bottom edge 487 of the node-walls 474 are identical in length, as are the two side edges 490. The side edges 490 of the node walls 474 and non-node walls 472 are also identical in length and are at angle a with respect to each other. The angle a may be determined by extending a first line from vertex 479 perpendicular to the axis (not shown in this figure) and to a point on the axis, and extending a second line from vertex 483 to the same point on the axis. The angle between these two lines is equivalent to angle a.
Top edge 488 and bottom edge 489 of non-node walls 472 have a curvature that conforms to the geometry of the core cylinder 450. Because the top edge 488 traces the outer surface 453 of the cylinder, and the bottom edge 489 traces the inner surface 455 of the cylinder, and because the outer surface 453 has a larger radius than the inner surface 455, the top edge 488 is longer than the bottom edge 489.
Top edge 488 is shaped like an arc section of an ellipse formed by intersecting a plane with the outer surface 453 of the cylinder 450. The plane is parallel to the radius of the cylinder and contains the two vertices 477, 476 of top edge 488. Similarly, the bottom edge 489 is shaped as an arc section of an ellipse formed by intersecting a plane with the inner surface of the cylinder. The plane is parallel to the radius of the cylinder and contains the two vertices 479, 478 of bottom edge 489. If the cells are shaped approximately as a regular hexagon, these planes may be approximated as planes parallel to the radius and rotated by approximately 120 degrees with respect to the axis. In
The calculations for determining the shape of edges 488-489 may be simplified by approximating edges 488-489 as arcs of a circle having a radius equivalent to the radius of the cylindrical surface on which the curved edges 488-489 lie. Further, the arc-length of the curved top or bottom edges may be approximated as Θ·R, where Θ is equal to the angle traversed by the curved edges 488-489. These approximations are fairly suitable if the size of the cells is much smaller than the radius of the cylinder, but becomes less accurate as the size of the cell becomes closer to the size of the cylinder.
Although the ribbons are described and depicted above as being identical for all locations throughout the cylindrical core geometry, varying core geometries may require different ribbon geometries. For manufacturing purposes, it is beneficial to have the smallest number of ribbon geometries.
For certain cylindrical shapes, only one ribbon geometry needs to be made. For others, a small number of ribbon geometries need to be made. For the most complex cylindrical geometries, each ribbon would have to be customized for its location.
The presence of radial symmetry in a cylindrical geometry allows the use of identical ribbons running in a direction parallel to that symmetry. For example, a regular cylinder has radial symmetry around its axis, meaning that identical ribbons may be used if the ribbons run in the direction perpendicular to the axis of the cylinder. A tapered cylinder or a cylinder with a bulge in the middle similarly has radial symmetry around its axis, so identical ribbons may be used if the ribbons run in the direction parallel to the radius of the cylinder. Further, with a torus, which is a cylinder whose axis has a constant radius of curvature, identical ribbons may be used if they are positioned such that they are parallel to the major radius of the torus.
Although some cylinder geometries may not have any of these characteristics along their entire length, some cylinder geometries may nevertheless be broken down into sections, each of which have these characteristics (for example, multiple sections of a torus attached at their ends and rotated with respect to each other, or a torus section followed by a tapered straight cylindrical section). For such cylinders, each section may be made of identical ribbons.
Further, for any desired geometry which does not exactly match one of the “ideal” shapes having characteristics described above (such as symmetry), but almost matches such an ideal shape, an ideal shape may be manufactured using the above-described methodologies and then formed (e.g., the shape of the cylinder can be changed through the application of force) into the desired non-ideal shape. Although some forming would be required in this situation, the forming would be minimal in comparison with forming a shape from flat core material.
As shown in
The sections have the same order and shape as the walls in the linear sequence 460. The shape of the edges of the sections is also the same as the shape of the corresponding edges of the walls. Thus, the first section 474 has the same shape as node wall 474, the second section 472 has the same shape as non-node wall 472, and so on. Further, the order of the sections in the flat ribbon 496 is the same as the order of the cell walls shown in
The flat ribbon 496 shown in
When the ribbon 496 shown in
When the flat ribbon shape 496 is determined, a physical ribbon can be cut out of a base material such as metal or paper by conventional methods such as a stamp and press apparatus. This physical ribbon will then be folded to match the shape of the cells in the cylindrical core.
The edges 490 that separate the sections in the ribbon represent lines at which folds or bends will be made and are referred to herein as “fold lines.” The flat ribbons are folded to form contoured ribbons with troughs and ridges that correspond to the linear sequence of half cells. The ribbons should be folded to angles such that the ribbons form the cells.
For the cell shape depicted in
As shown in
If the ribbons were pre-folded, the cylindrical core is completed. Alternatively, if the ribbons were simply pre-stressed, then when it is desired to assemble the full structure, the ribbons may be pulled apart such that the structure is expanded and the ribbons are formed into the final desired structure. The expanded assembly of ribbons may be cured or otherwise solidified into the appropriate geometry.
The teachings of this disclosure can be used to make a curved honeycomb core in a wide variety of geometries while requiring minimal forming.
While the disclosure has been described with reference to various embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation to the teachings of the disclosure without departing from the essential scope thereof. Therefore it is intended that the disclosure not be limited to the particular embodiment disclosed herein contemplated for carrying out the methods of this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
