Method and apparatus for forming composite structural elements

Abstract

Method, system and designed aircraft for designing a structural element for an aircraft SOLUTION: Defining a structural element, the structural element including a composite structure and a candidate woven wire cloth, the candidate woven wire cloth forming an electrically conductive path within the structural element; This includes generating a computer model of the composite structure, generating a computer model of the candidate woven wire cloth, forming a virtual prototype of the structural element including the composite structure and the candidate woven wire cloth incorporated therein, simulating, via the finite element model, a direct current injection event into the virtual prototype, identifying an expected conductive path, identifying a risk associated with the expected conductive path in the virtual prototype, and implementing the composite structure and the candidate woven wire cloth as the structural element when the risk is less than a threshold risk.SELECTED DRAWING: Figure 3

Description

[Background technology]

[0001] Structural elements of aircraft and other devices (e.g., wind turbines) can be manufactured using composite materials. Composite materials are lightweight materials that are lighter and have better mechanical and fatigue properties than mechanically equivalent metallic structures. Composite materials, such as glass fiber, carbon fiber, aramid fiber, or boron fiber, are combined with coupling agents, such as epoxy resins / hardeners, ceramic materials, or metal matrices. Aircraft with composite structures and / or elements have been shown to have better mechanical and structural performance than metallic structures due to improved strength-to-weight ratios. The use of composite structures can reduce weight and therefore fuel consumption.

[0002]

[0002] Aircraft containing composite structures and / or components are exposed to various electromagnetic effects (EME), including, but not limited to, lightning strikes and high-intensity radiated fields (HIRF). Composite materials have lower electrical conductivity and poor electromagnetic shielding effectiveness compared to aluminum. The lower electrical conductivity results in lower current dissipation, which can affect structural integrity during electromagnetic effects (EME), such as lightning strikes. Specifically, when an aircraft is struck by lightning, conductive paths in the aircraft's skin allow electricity to travel along the skin and exit at some other location on the aircraft. During a lightning strike, current may traverse all available paths to complete the lightning path, including, but not limited to, cloud-to-ground, cloud-to-cloud, and ground-to-cloud. Without adequate conductive paths, arcing and hot spots may occur, affecting the aircraft's skin. Additionally, composite materials have poor electrical shielding capabilities, which can increase the lightning threat to wiring and systems within the aircraft. Summary of the Invention

[0003]

[0003] Electrical currents generated as a result of an EME event (eg, a lightning strike) need to be directed away from composite structures to minimize the potential for compromising the structural integrity of the composite structure.

[0004]

[0004] Concepts described herein provide systems, apparatus, and / or methods relating to the use of composite aircraft elements (e.g., wings, fuselages, flight control surfaces, flaps, elevators, ailerons, rudder, engine cowlings, or portions thereof) where the composite elements are fabricated from a composite material having an interwoven wire fabric to minimize electromagnetic effects during use.

[0005] One aspect of the present disclosure may include a method for designing a structural element for an aircraft, the method including: defining the structural element, the structural element including a composite structure and a candidate woven wire cloth, the candidate woven wire cloth arranged to form an optimal conductive path within the structural element; generating a computer model of the composite structure; generating a computer model of the candidate woven wire cloth architecture; forming a virtual prototype of the structural element, the virtual prototype of the element including the computer model of the composite structure having the computer model of the candidate woven wire cloth embedded therein; simulating a direct current injection event into the virtual prototype via a finite element model; identifying a predicted conductive path within the virtual prototype based on the simulation of the direct current injection event into the virtual prototype; identifying a risk associated with the predicted conductive path within the virtual prototype; and implementing the composite structure and the candidate woven wire cloth as the structural element when the risk associated with the predicted conductive path in the virtual prototype is less than a threshold risk.

[0006] Another aspect of the present disclosure may include fabricating a structural element including a composite structure and candidate conductive elements, where the candidate conductive elements are fabricated as a laminate disposed over a portion of the composite structure.

[0007] Another aspect of the present disclosure may include defining the candidate conductive element as an interwoven wire cloth (IWWF), where the IWWF is arranged as a laminate disposed over a portion of the composite structure.

[0008] Another aspect of the present disclosure may include defining the candidate conductive elements as interwoven wire cloth (IWWF) having a topology.

[0009] Another aspect of the present disclosure may include defining a topology of an IWWF by defining one or more of the wire material, wire gauge, wire density, weave, or orientation of the IWWF.

[0010] Another aspect of the present disclosure may include defining candidate conductive elements, where the candidate conductive elements are arranged to form conductive paths within a structural element by defining the candidate conductive elements to be coextensive with a surface of a composite structure.

[0011]

[0011] Another aspect of the present disclosure may include identifying risks associated with expected conductive paths within a virtual prototype by identifying risks to the structural integrity of structural elements associated with the expected conductive paths within the virtual prototype.

[0012]

[0012] Another aspect of the present disclosure may include identifying the risk of a fire event in a structural element associated with a predicted conductive path in a virtual prototype.

[0013] Another aspect of the present disclosure may include a system for designing structural elements for an aircraft, wherein the system includes a controller having algorithm code stored in a non-volatile memory thereof. The algorithmic code is executable to: define a composite structure for the structural element; define candidate conductive elements, the candidate conductive elements being arranged to form conductive paths within the structural element; generate a first computer model of the composite structure; generate a second computer model of the candidate conductive elements; form a virtual prototype of the structural element, the virtual prototype of the structural element including the first computer model of the composite structure embedded with the second computer model of the candidate conductive elements; simulate a direct current injection event into the virtual prototype of the structural element via a finite element model; identify a likely conductive path within the virtual prototype based on the simulation of the direct current injection event into the virtual prototype; identify a risk associated with the likely conductive path in the virtual prototype; and implement the composite structure and the candidate conductive elements as the structural element when the risk associated with the likely conductive path in the virtual prototype is less than a threshold risk.

[0014] Another aspect of the present disclosure may include an aircraft having a structural element in the form of a composite structure and a conductive element, where the conductive element is arranged to form a conductive path within the structural element. The conductive element is designed by generating a first computer model of the composite structure, generating second computer models of candidate conductive elements, forming a virtual prototype of the structural element, the virtual prototype of the structural element including the first computer model of the composite structure embedded with the second computer models of the candidate conductive elements, simulating a direct current injection event into the virtual prototype of the structural element via a finite element model, identifying a predicted conductive path within the virtual prototype based on the simulation of the direct current injection event into the virtual prototype, identifying a risk associated with the predicted conductive path within the virtual prototype, and selecting the candidate conductive element as the conductive element when the risk associated with the predicted conductive path in the virtual prototype is less than a threshold risk.

[0015]

[0015] The foregoing summary is not intended to represent all possible embodiments or all aspects of the present disclosure. Rather, the foregoing summary is intended to illustrate some of the novel aspects and features disclosed herein. The above-described features and advantages of the present disclosure, as well as other features and advantages, will become readily apparent from the following detailed description of exemplary embodiments and modes for carrying out the disclosure when taken in conjunction with the accompanying drawings and the appended claims.

[0016]

[0016] One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0017] [Figure 1]

[0017] Schematically illustrates an aircraft including structural elements having a composite structure according to the present disclosure. [Figure 2]

[0018] 1A and 1B schematically illustrate a cutaway side view of a portion of one embodiment of a structural element having a composite structure according to the present disclosure. [Figure 3]

[0019] 1 shows a schematic flow chart of a process according to the present disclosure. [Figure 4]

[0020] 1 pictorially illustrates a portion of a ply of a composite structure of a structural element having interwoven fibers according to the present disclosure. [Figure 5]

[0021] 1 pictorially illustrates a portion of a ply of a composite structure of a structural element having woven fibers and a first candidate design of an internally embedded woven wire cloth (IWWF) according to the present disclosure. [Figure 6]

[0022] 10 pictorially illustrates a portion of a ply of a composite structure of a structural element having woven fibers and a second candidate design of an internally embedded woven wire cloth (IWWF) according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018]

[0023] The accompanying drawings are not necessarily to scale and may present somewhat simplified representations of various features of the present disclosure disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, the details associated with such features being determined in part by the particular intended application and environment of use.

[0019]

[0024] The components of the embodiments of the present disclosure described and illustrated herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description is not intended to limit the scope of the disclosed embodiments as claimed, but is merely representative of possible embodiments thereof. Additionally, although numerous specific details are set forth in the following description to provide a thorough understanding of the embodiments disclosed herein, some embodiments may be practiced without some of these details. Moreover, for clarity, certain technical matters understood in the relevant art have not been described in detail to avoid obscuring the disclosure. For convenience and clarity, directional terms such as top, bottom, left, right, top, above, upward, downward, below, rear, and front may be used with respect to the drawings. These and similar directional terms should not be construed as limiting the scope of the disclosed embodiments.

[0020]

[0025] As used herein, the term "system" may refer to one or a combination of mechanical and electrical actuators, sensors, controllers, application specific integrated circuits (ASICs), combinatorial logic circuits, software, firmware, and / or other components arranged to provide a described functionality.

[0021]

[0026] Embodiments may be described herein in terms of functional and / or logical block components and various processing steps. Such block components may be realized by a combination or collection of mechanical and electrical hardware, software, and / or firmware components configured to perform the specified functions. For example, an embodiment may employ various combinations of mechanical and electrical components, integrated circuit components, memory elements, digital signal processor elements, logic elements, look-up tables, and the like, which may perform various functions under the control of one or more microprocessors or other control devices. Additionally, those skilled in the art will understand that the illustrated embodiments may be implemented in conjunction with mechanical and / or electrical systems, and that the vehicle systems described herein are merely exemplary embodiments of possible implementations.

[0022]

[0027] For purposes of brevity, some known components and techniques and other functional aspects of the system (and individual operating components of the system) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may exist in an embodiment of the present disclosure.

[0023]

[0028] Furthermore, the initial definition of an acronym or other abbreviation applies to subsequent uses of the same abbreviation herein and applies mutatis mutandis to normal grammatical variations of the originally defined abbreviation, and unless stated to the contrary, measurements of a property are specified by the same technique as previously or subsequently mentioned for the same property.

[0024]

[0029] This disclosure is not limited to the specific embodiments and methods described below, as specific components and / or conditions may, of course, vary. Accordingly, the terminology used herein is used for the purpose of describing particular embodiments of the present disclosure and is not intended to be limiting.

[0025]

[0030] Also, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, the singular element "a," "an," and "the" are intended to include plural elements.

[0026]

[0031] The use of ordinal numbers such as first, second, and third does not necessarily imply an ordinal ranking, but rather may distinguish between multiple instances of an action or structure.

[0027]

[0032] Numerical values ​​of parameters (e.g., amounts or conditions) in this specification, including the appended claims, are understood to be modified by the term "about," regardless of whether "about" actually appears before the numerical value. "About" indicates that the numerical value being stated allows for some slight imprecision (e.g., approaching the numerical precision, being about or reasonably close to the numerical value, approximately). Where the imprecision provided by "about" is not otherwise understood in this art in its ordinary sense, "about," as used herein, will at least account for the variation that can result from ordinary methods of measuring and using such parameters. Furthermore, the disclosure of a range includes the disclosure of all numerical values ​​and sub-ranges within that entire range. Each value within a range and the endpoints of a range are all disclosed herein as separate embodiments.

[0028]

[0033] As used herein, terms such as "vertical," "horizontal," "left," "right," "top," "bottom," and similar expressions are merely non-limiting terms describing various elements as illustrated in the figures and are not intended to limit the scope of the present disclosure.

[0029]

[0034] 1 and 2 schematically illustrate an element of a fixed-wing aircraft 10 having one or more structural elements 100 with a composite structure 101 including a skin portion 102 fabricated to incorporate a conductive layer 135. In this case, the conductive layer 135 incorporates an embedded conductive element 130 including an interwoven wire cloth (IWWF) layer 132 having characteristics that shed or otherwise mitigate electromagnetic effects (EME), including but not limited to lightning strikes. FIG. 2 illustrates a partial cutaway view of one embodiment of the skin portion 102 of the structural element 100 fabricated to incorporate the conductive layer 135. Referring again to FIG. 1 , the aircraft 10 includes a fuselage 12, one or more wings 14, horizontal stabilizers 16, and vertical stabilizers 18. The aircraft 10 also includes one or more turbine engines 19. Each of the one or more wings 14, horizontal stabilizers 16, and vertical stabilizers 18 includes a movable surface 25 disposed on the outer skin of the aircraft 10. The moving surfaces 25 include, for example, flaps, ailerons, elevators, stabilizers, etc. Any one, combination, or all of the aforementioned elements of the aircraft 10 may be a structural element 100 fabricated as a composite structure 101 including an embodiment of the conductive layer 135. The structural element 100 may be, without limitation, a flight control surface, a flap, an elevator, an aileron, or a rudder, or a portion thereof, a radome or a portion thereof, an engine cowling or a portion thereof, or other element. Alternatively, the concepts described herein may be employed in structural elements of propulsion devices such as, without limitation, flying cars, drones, electric vertical take-off and landing (eVTOL), etc. Alternatively, the concepts described herein may be employed in structural elements of marine systems, land vehicles, or other vehicles. Alternatively, the concepts described herein may be employed in structural elements of fixtures, such as, for example, wind turbines (not shown).

[0030]

[0035] FIG. 2 shows a cutaway cross-sectional view of the structural element 100 of FIG. 1 including a conductive layer 135 having embedded conductive elements 130 including an IWWF layer 132. In this case, the conductive elements 130 are fabricated as a laminate disposed over a portion of the composite structure 101 and disposed on a surface 145 of a substrate 140. The structural element 100 includes a substrate 140 and a conductive layer 135. In this case, the conductive layer 135 is formed of the embedded conductive elements 130 including the IWWF 132, the surfacer layer 120, and the paint layer 110. The layers above the substrate 140 form the conductive layer 135. Depending on the embodiment, the conductive layer 135 may include only the embedded conductive elements 130, the surfacer layer 120, and the paint layer 110. Alternatively, the conductive layer 135 may include other layers in addition to or instead of those illustrated in this example.

[0031]

[0036] In one embodiment, the structural element 100 is a composite structure 101 that functions as a skin portion 102 of a fuselage or another element. Such a composite structure may include a laminate made of fiber-reinforced polymer. The IWWF 132 of the embedded conductive element 130 includes a plurality of woven wires. These wires provide a conductive path for electromagnetic effects, such as those that may result from a lightning strike. The surfacer layer 120 provides a coating or surface for the application of the paint layer 110. The surfacer layer 120 and the paint layer 110 may form a dielectric component. The dielectric component may include other materials or layers, such as a sealant, a non-conductive primer, or some combination of these materials, along with the surfacer layer 120 and the paint layer 110. The thickness of the dielectric layer over the embedded conductive element 130 can affect the dissipation of electrical energy from a lightning strike. As the dielectric thickness increases, the integrity of a portion of the composite structure may be affected when struck by lightning.

[0032]

[0037] In one embodiment, the embedded conductive element 130 is fabricated as an IWWF 132, as described herein. Alternatively, the embedded conductive element 130 may be fabricated as an expanded copper foil. The IWWF 132 provides a woven or knitted fabric with more uniform conductivity compared to expanded copper foil.

[0033]

[0038] The IWWF 132 has a topology that is defined and designed in terms of wire material(s), wire gauge(s), wire density (e.g., strands per square inch), weave, and orientation, where the orientation is defined relative to a longitudinal axis, a transverse axis, a center point, or another reference element of the structural element 100. As will be appreciated, the topology defines and describes the properties of the IWWF 132. These properties are preserved under continuous deformations, such as stretching, twisting, crushing, and bending, that occur when the IWWF 132 is conformed to the surface of the composite structure 101 in forming the structural element 100.

[0034]

[0039] The IWWF 132 of the embedded conductive element 130 is configured as a woven fabric made from conductive wire, which may be aluminum, an aluminum alloy, copper, a copper alloy, or another conductive material.

[0035]

[0040] IWWF132 woven fabrics may take the form of one or more of the following weaves, but are not limited to: plain Dutch weave, twill weave, plain weave, twill Dutch weave, lock crimp weave, intercrimp weave, twill Dutch double weave, twisted weave, and the like.

[0036]

[0041] The woven fabric of IWWF132 may have a longitudinal wire system and a weft wire system. The longitudinal wire system is called the warp yarns, and the weft wire system is called the weft or fill yarns. In one embodiment, the warp and weft yarns are at a 90 degree angle to each other. The warp and weft yarns are interlaced according to specific rules, thus creating a wire composite or woven fabric.

[0037]

[0042] The type of interlacing of warp and weft or weft threads is called the weave. The interlacing sequence is repeated in the weave after a certain number of warp and weft threads have been stacked. These repetitions are called weave repeats.

[0038]

[0043] The number of warp wires, weft wires, and wire counts depending on the weave are called the wire fabric configuration. This configuration determines the construction of the wire fabric and indicates the number of warp and weft threads in a particular gauge (e.g., per cm, per 10 cm, or greater than the fabric width).

[0039]

[0044] The selectable design elements of IWWF132 can be described in terms of warp, longitudinal wire gauge, weft, weft wire gauge, weave, warp wire count, weft wire count, wire material, diameter of warp and weave elements, opening size, braid wire, and wire density.

[0040]

[0045] Other design options for the IWWFs 132 further include the orientation of the IWWFs 132 relative to the longitudinal or transverse axis of the respective component skin section 102, where the IWWFs 132 provide resistance to lightning strikes. The design space for the IWWFs 132 can be limitless. Depending on how you want the current to flow through the aircraft, you can weave different wires in different directions or follow almost any fabric topology.

[0041]

[0046] While advanced modeling approaches have attempted to mitigate EME, they are limited to idealizing the ply as a single, uniform response, which does not accurately capture the effect of the individual current paths built into the structure, nor does it capture the single contact points that may prevent arcing.

[0042]

[0047] The concepts described and claimed herein provide an analytical structure that defines how currents flow through discrete paths within composite structures to enable the design and analysis of improved EME solutions.

[0043]

[0048] 3 illustrates, in flowchart form, a computational analysis process 300 for identifying the design of one embodiment of a structural element 100 having a composite structure 101 including a skin portion fabricated to incorporate a conductive layer 135, where the conductive layer 135 incorporates an embedded conductive element 130 that, in one embodiment, includes an interwoven wire cloth (IWWF) layer 132.

[0044]

[0049] The computational analysis process 300 includes identifying, incorporating, and developing a computational model of the design of the structural elements 100 comprising the composite structure 101 (step 310).

[0045]

[0050] FIG. 4 pictorially shows a portion of a ply 102 of a composite structure 101 of a structural element 100 having interwoven fibers 103 .

[0046]

[0051] 3, the computational model of the structural element 100 may take the form of, but is not limited to, a finite element model, a finite mesh, a finite difference framework, etc. The development of the finite element model may be created with commercially available software capable of developing finite element or finite difference frameworks. The structure may have various levels of fidelity, from a global FEM mesh to a detailed element mesh.

[0047]

[0052] At least one or more candidate designs for the IWWF 132 are developed along with a corresponding computational model. Selectable design elements of the IWWF 132 may be described in terms of warp, longitudinal wire gauge, weft, weft wire gauge, weave, warp wire count, weft wire count, wire material, warp and weave element diameter, aperture size, braid wire, and wire density. Other selectable design elements of the IWWF 132 further include the orientation of the IWWF 132 relative to the longitudinal or transverse axis of the respective component skin portion 102.

[0048]

[0053] Candidate designs for IWWF 132 are identified, and computational models of the candidate IWWF 132 are developed and placed, embedded, inserted, or otherwise virtually incorporated onto the computational model of the composite structure 101 to form a virtual prototype of the structural element 100 (step 320).

[0049]

[0054] FIG. 5 pictorially shows a portion of a ply 102 of a composite structure 101 of a structural element 100 having woven fibers 103 and a first candidate design 133 of IWWF 132 embedded therein.

[0050]

[0055] Referring again to FIG. 3 , the virtual prototype of the structural element 100 developed in step 320 is subjected to the injection of a simulated DC current, e.g., to simulate a lightning strike (step 330). This involves employing an embedded element approach within the framework of the finite element method (FEM). The embedded element approach allows lower-order elements (e.g., rods / trusses, beams, shells) to be inserted into higher-order elements (e.g., solids) to model discrete areas of interest. A standard finite element mesh is used with the included IWWF discrete architecture. For implementation, any finite element mesh with directional anisotropic conductivity assignments can be used. Truss elements (or beams) can be inserted in any orientation. In one embodiment, elements can be positioned orthogonal to each other. Alternatively, elements can be inserted arbitrarily. When modeling this approach, current distribution is more heavily handled by the IWWF embedded elements, providing a more accurate description of how currents flow through the virtual prototype of the aircraft structural element 100. This results in improved accuracy of the currents and, by using lower-order elements, increases computational efficiency. The analytical tools that enable this analysis include conductive FEM (finite element model) analysis, which allows the analysis to be performed within the framework of standard analysis, especially for current injections such as lightning strikes.

[0051]

[0056] The simulated injection of DC current into the virtual prototype of the structural element 100 results in identifying expected conductive paths through the structural element 100 (step 340). The expected conductive paths through the structural element 100 are analyzed to identify, locate, determine, detect, and otherwise quantify risks to the structural integrity of the structural element 100, i.e., to identify whether, where, and to what extent the expected conductive paths through the structural element 100 affect the structural integrity of the virtual prototype of the structural element 100 (step 345). This analysis may take the form of a risk assessment, such as a failure model analysis (FMA), a failure mode and effects analysis (FMEA), or a failure mode, effects, and severity analysis (FMECA). The quantified risk to the structural integrity of the structural element 100 is compared to a threshold risk to assess whether the expected conductive paths through the structural element 100 are expected to have a negative impact on the structural integrity of the virtual prototype of the structural element 100.

[0052]

[0057] When the predicted conductive path through the structural element 100 is predicted to have a negative effect (Y) on the structural integrity of the virtual prototype of the structural element 100, the current candidate design of the IWWF 132 is discarded and a new candidate design of the IWWF 132 is selected. A computational model of the new candidate design of the IWWF 132 is developed, embedded, inserted, or otherwise virtually incorporated into the computational model of the composite structure 101 to form an updated virtual prototype of the structural element 100 (step 350).

[0053]

[0058] FIG. 6 pictorially illustrates a portion of a ply 102 of a composite structure 101 of a structural element 100 having woven fibers 103 and a second candidate design 134 of IWWF 132 embedded therein.

[0054]

[0059] Referring again to FIG. 3, the updated virtual prototype of the structural element 100 is subjected to a simulated injection of DC current (step 330) and process steps 340 and 350 are repeated.

[0055]

[0060] The current candidate design of IWWF 132 is deemed acceptable (step 360) when the predicted conductive paths through structural element 100 do not negatively impact the structural integrity of the virtual prototype of structural element 100 (N).

[0056]

[0061] The current candidate design of the IWWF 132 may be manufactured into hardware (step 370) and installed in an embodiment of an aircraft structural element 100 for further testing, development, and / or production implementation (step 380).

[0057]

[0062] In this manner, when the risk associated with the predicted conductive paths in the virtual prototype is less than the threshold risk, the composite structure 101 and candidate conductive element in the form of IWWF132's current candidate design may be implemented as a structural element 100 for further testing and development.

[0058]

[0063] The concepts described herein can be employed in designing new protection schemes, including IWWF orientation, to minimize the effects of direct lightning strikes, such as structural risks, to structural elements 100 manufactured using composite materials. The concepts can also be used in repairing structural elements.

[0059]

[0064] When scarfing acre structures, a conductive path is required, and as a result, large amounts of IWWF are often used to ensure contact between the buried wires. Using this analysis technique, electrical conductivity can be more assured while minimizing material.

[0060]

[0065] Additionally, the concepts described herein can be used to help predict, identify, and mitigate arcing and spark events inside fastener holes in structural elements.

[0061]

[0066] As noted above and reiterated below, the present disclosure includes, without limitation, the following exemplary embodiments.

[0062]

[0067] Article 1. simulating a direct current injection event into the virtual prototype of the structural element via a finite element model; identifying a likely conductive path in the virtual prototype based on the simulation of the direct current injection event into the virtual prototype; identifying a risk associated with the likely conductive path in the virtual prototype; and implementing the composite structure and the candidate conductive elements as the structural element when the risk associated with the likely conductive path in the virtual prototype is less than a threshold risk.

[0063]

[0068] Article 2. 10. The method of claim 1, further comprising manufacturing the structural element comprising the composite structure and the candidate conductive element, wherein the candidate conductive element is manufactured as a laminate disposed on a portion of the composite structure.

[0064]

[0069] Article 3. 3. The method of claim 1 or 2, wherein defining the candidate conductive element includes defining the candidate conductive element as an interwoven wire cloth (IWWF), the interwoven wire cloth (IWWF) being arranged as a laminate disposed over a portion of the composite structure.

[0065]

[0070] Article 4. 4. The method of any one of clauses 1 to 3, wherein defining the candidate conductive element as an interwoven wire cloth (IWWF) includes defining a topology of the IWWF.

[0066]

[0071] Article 5. 5. The method of any one of clauses 1 to 4, wherein defining the topology of the IWWF includes defining one of the wire material, wire gauge, wire density, weave, or orientation of the IWWF.

[0067]

[0072] Article 6. 6. The method of any one of clauses 1 to 5, wherein defining the candidate conductive elements includes defining the candidate conductive elements to be coextensive with a surface of the composite structure, the candidate conductive elements being positioned to form the conductive pathway within the structural element.

[0068]

[0073] Article 7. 7. The method of any one of clauses 1 to 6, wherein identifying the risks associated with the expected conductive path in the virtual prototype includes identifying risks to the structural integrity of the structural elements associated with the expected conductive path in the virtual prototype.

[0069]

[0074] Article 8. 8. The method of any one of clauses 1 to 7, wherein identifying the risk associated with the expected conductive path in the virtual prototype includes identifying a risk of a fire event in the structural element associated with the expected conductive path in the virtual prototype.

[0070]

[0075] Article 9. 1. A system for designing a structural element for an aircraft, comprising: a controller having algorithmic code stored in a non-volatile memory thereof, the algorithmic code comprising: defining a composite structure for the structural element; defining candidate conductive elements, the candidate conductive elements being arranged to form conductive paths within the structural element; generating a first computer model of the composite structure; generating a second computer model of the candidate conductive elements; and forming a virtual prototype of the structural element, the virtual prototype of the structural element having the second computer model of the candidate conductive elements incorporated therein. forming a virtual prototype of the structural element, the virtual prototype including the first computer model of the composite structure; simulating a direct current injection event into the virtual prototype of the structural element via a finite element model; identifying a predicted conductive path in the virtual prototype based on the simulation of the direct current injection event into the virtual prototype; identifying a risk associated with the predicted conductive path in the virtual prototype; and implementing the composite structure and the candidate conductive element as the structural element when the risk associated with the predicted conductive path in the virtual prototype is less than a threshold risk.

[0071]

[0076] Article 10. The system described in clause 9, wherein the algorithm code executable to define the candidate conductive element includes the algorithm code executable to define the candidate conductive element as an interwoven wire cloth (IWWF), the interwoven wire cloth (IWWF) being arranged as a laminate disposed over a portion of the composite structure.

[0072]

[0077] Article 11. 11. The system of clause 9 or 10, wherein the algorithmic code executable to define the candidate conductive element as an interwoven wire cloth (IWWF) includes the algorithmic code executable to define a topology of the IWWF with one of a specified wire material, wire gauge, wire density, weave, or orientation.

[0073]

[0078] Article 12. 12. The system of any one of clauses 9 to 11, wherein the algorithmic code executable to define the topology of the IWWF includes the algorithmic code executable to define one of a wire material, a wire gauge, a wire density, a weave, or an orientation of the IWWF.

[0074]

[0079] Article 13. 13. The system of any one of clauses 9 to 12, wherein the algorithm code executable to define the candidate conductive elements includes the algorithm code executable to define the candidate conductive elements to be coextensive with a surface of the composite structure, the candidate conductive elements being positioned to form the conductive pathway within the structural element.

[0075]

[0080] Article 14. 14. The system of any one of clauses 9 to 13, wherein the algorithm code executable to identify the risks associated with the expected conductive path in the virtual prototype comprises the algorithm code executable to identify risks to the structural integrity of the structural element associated with the expected conductive path in the virtual prototype.

[0076]

[0081] Article 15. 15. The system of any one of clauses 9 to 14, wherein the algorithm code executable to identify the risk associated with the expected conductive path in the virtual prototype comprises the algorithm code executable to identify a risk of a fire event in the structural element associated with the expected conductive path in the virtual prototype.

[0077]

[0082] Article 16. 1. An aircraft comprising a structural element, the structural element comprising a composite structure and an electrically conductive element, the electrically conductive element being arranged to form an electrically conductive path within the structural element, the electrically conductive element being designed by the following steps: generating a first computer model of the composite structure; generating second computer models of candidate electrically conductive elements; forming a virtual prototype of the structural element, the virtual prototype of the structural element including the first computer model of the composite structure embedded with the second computer models of the candidate electrically conductive elements; simulating a direct current injection event into the virtual prototype of the structural element via a finite element model; identifying a likely electrically conductive path within the virtual prototype based on the simulation of the direct current injection event into the virtual prototype; identifying a risk associated with the likely electrically conductive path in the virtual prototype; and selecting the candidate electrically conductive element as the electrically conductive element when the risk associated with the likely electrically conductive path in the virtual prototype is less than a threshold risk.

[0078]

[0083] Article 17. 17. The aircraft of clause 16, wherein the structural element comprises one of a wing, a fuselage, a horizontal stabilizer, a vertical stabilizer, or a flap.

[0079]

[0084] Article 18. 18. The aircraft of clause 16 or 17, wherein the conductive element is manufactured as a laminate disposed on a portion of the composite structure.

[0080]

[0085] Article 19. 19. The aircraft of any one of clauses 16 to 18, further comprising the conductive element being an interwoven wire cloth (IWWF), the interwoven wire cloth (IWWF) being arranged as a laminate disposed over a portion of the composite structure.

[0081]

[0086] Article 20. 20. The aircraft of any one of clauses 16 to 19, further comprising an interwoven wire cloth (IWWF) having a topology comprising one of a defined wire material, wire gauge, wire density, weave, or orientation.

[0082]

[0087] The detailed description and drawings or figures support and explain the present teachings, the scope of which is defined only by the claims. Although the best mode and several alternative embodiments for carrying out the present teachings have been described in detail, there are various alternative designs and embodiments for implementing the present teachings as defined within the scope of the claims.

Claims

1. A method for designing a structural element (100), comprising: defining a composite structure (101) for said structural element (100); defining candidate conductive elements (130), the candidate conductive elements (130) being arranged to form conductive paths within the structural element (100); generating a first computer model of the composite structure (101); generating a second computer model of the candidate conductive element (130); creating a virtual prototype of the structural element (100), the virtual prototype of the structural element (100) including the first computer model of the composite structure (101) having the second computer model of the candidate conductive element (130) embedded therein; simulating a DC current injection event into the virtual prototype of the structural element (100) via a finite element model; identifying a likely conductive path within the virtual prototype based on a simulation of the DC current injection event into the virtual prototype; Identifying risks associated with the anticipated conductive paths within the virtual prototype; and The method includes implementing the composite structure (101) and the candidate conductive element (130) as the structural element (100) when the risk associated with the expected conductive path in the virtual prototype is less than a threshold risk.

2. 2. The method of claim 1, further comprising manufacturing the structural element (100) including the composite structure (101) and the candidate conductive element (130), wherein the candidate conductive element (130) is manufactured as a laminate disposed on a portion of the composite structure (101).

3. 2. The method of claim 1, wherein defining the candidate conductive element (130) includes defining the candidate conductive element (130) as a woven wire cloth (IWWF) (132), the woven wire cloth (IWWF) (132) being arranged as a laminate disposed over a portion of the composite structure (101).

4. The method of claim 3, wherein defining the candidate conductive element (130) as an interwoven wire cloth (IWWF) (132) includes defining a topology of the IWWF (132).

5. 5. The method of claim 4, wherein defining the topology of the IWWF (132) includes defining one of a wire material, a wire gauge, a wire density, a weave, or an orientation of the IWWF (132).

6. 2. The method of claim 1, wherein defining the candidate conductive elements (130) is arranged to form the conductive pathway within the structural element (100), and defining the candidate conductive elements (130) includes defining the candidate conductive elements (130) to be coextensive with a surface (145) of the composite structure (101).

7. 2. The method of claim 1, wherein identifying the risks associated with the expected conductive paths in the virtual prototype comprises identifying risks to the structural integrity of the structural element (100) associated with the expected conductive paths in the virtual prototype.

8. 2. The method of claim 1, wherein identifying the risk associated with the expected conductive path in the virtual prototype comprises identifying a risk of a fire event in the structural element (100) associated with the expected conductive path in the virtual prototype.

9. A system for designing a structural element (100) for an aircraft (10), comprising: a controller having algorithm code stored in a non-volatile memory thereof, the algorithm code comprising: defining a composite structure (101) for said structural element (100); defining candidate conductive elements (130), the candidate conductive elements (130) being arranged to form conductive paths within the structural element (100); generating a first computer model of the composite structure (101); generating a second computer model of the candidate conductive element (130); creating a virtual prototype of the structural element (100), the virtual prototype of the structural element (100) including the first computer model of the composite structure (101) having the second computer model of the candidate conductive element (130) embedded therein; simulating a DC current injection event into the virtual prototype of the structural element (100) via a finite element model; identifying a likely conductive path within the virtual prototype based on a simulation of the DC current injection event into the virtual prototype; Identifying risks associated with the anticipated conductive paths within the virtual prototype; and The system is capable of implementing the composite structure (101) and the candidate conductive element (130) as the structural element (100) when the risk associated with the expected conductive path in the virtual prototype is less than a threshold risk.

10. 10. The system of claim 9, wherein the algorithmic code executable to define the candidate conductive element (130) comprises the algorithmic code executable to define the candidate conductive element (130) as a woven wire cloth (IWWF) (132), the woven wire cloth (IWWF) (132) arranged as a laminate disposed over a portion of the composite structure (101).

11. 11. The system of claim 10, wherein the algorithmic code executable to define the candidate conductive element (130) as an interwoven wire cloth (IWWF) (132) comprises the algorithmic code executable to define a topology of the IWWF (132) with one of a defined wire material, wire gauge, wire density, weave, or orientation.

12. 12. The system of claim 11, wherein the algorithmic code executable to define the topology of the IWWF (132) comprises the algorithmic code executable to define one of a wire material, a wire gauge, a wire density, a weave, or an orientation of the IWWF (132).

13. 10. The system of claim 9, wherein the algorithm code executable to define the candidate conductive elements (130), wherein the candidate conductive elements (130) are positioned to form the conductive pathways within the structural element (100), comprises the algorithm code executable to define the candidate conductive elements (130) to be coextensive with a surface (145) of the composite structure (101).

14. 10. The system of claim 9, wherein the algorithmic code executable to identify the risks associated with the expected conductive paths in the virtual prototype comprises the algorithmic code executable to identify risks to the structural integrity of the structural element (100) associated with the expected conductive paths in the virtual prototype.

15. 10. The system of claim 9, wherein the algorithmic code executable to identify the risk associated with the expected conductive path in the virtual prototype comprises the algorithmic code executable to identify a risk of a fire event in the structural element (100) associated with the expected conductive path in the virtual prototype.

16. An aircraft (10) comprising a structural element (100) including a composite structure (101) and an electrically conductive element (130), The conductive elements (130) are arranged to form conductive paths within the structural element (100), and the conductive elements (130) include: generating a first computer model of the composite structure (101); generating a second computer model of the candidate conductive element (130); creating a virtual prototype of the structural element (100), the virtual prototype of the structural element (100) including the first computer model of the composite structure (101) having the second computer model of the candidate conductive element (130) embedded therein; simulating a DC current injection event into the virtual prototype of the structural element (100) via a finite element model; identifying a likely conductive path within the virtual prototype based on a simulation of the DC current injection event into the virtual prototype; Identifying risks associated with the anticipated conductive paths within the virtual prototype; and selecting the candidate conductive element (130) as the conductive element (130) when the risk associated with the expected conductive path in the virtual prototype is less than a threshold risk.

17. 17. The aircraft (10) of claim 16, wherein the structural element (100) comprises one of a wing, a fuselage (12), a horizontal stabilizer (16), a vertical stabilizer (18), or a flap.

18. 17. The aircraft (10) of claim 16, wherein the conductive element (130) is manufactured as a laminate disposed on a portion of the composite structure (101).

19. 17. The aircraft (10) of claim 16, wherein the candidate conductive elements (130) include a woven wire cloth (IWWF) (132), the woven wire cloth (IWWF) (132) arranged as a laminate disposed over a portion of the composite structure (101).

20. 17. The aircraft (10) of claim 16, wherein the woven wire cloth (IWWF) (132) topology comprises one of a defined wire material, wire gauge, wire density, weave, or orientation.

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