Aircraft wing composite rib with electrical ground path

Abstract

An aircraft wing composite rib having an electrical ground path is described. An example composite rib includes a carbon fiber reinforced plastic (CFRP) panel, a metal rib column, a metal fitting, and a metal grounding member. The metal rib column is coupled to the CFRP panel and is configured to be coupled to a spar of an aircraft wing, and the spar is coupled to a current return network (CRN) cable. The metal fitting is coupled to the CFRP panel and is configured to be coupled to a skin panel of the aircraft wing. The metal grounding member is positioned between the CFRP panel and the metal fitting. The metal grounding member provides an electrical grounding path extending from the metal fitting to the metal rib column.

Description

Technical Field

[0001] The present disclosure relates generally to composite ribs for aircraft wings and, more particularly, to composite ribs for aircraft wings having an electrical ground path. Background Art

[0002] Ribs are typically implemented as structural load-bearing devices within an aircraft wing (e.g., between upper and lower skin panels of the aircraft wing, and between front and rear spars of the aircraft wing) that are configured to provide tension and / or compression support to improve the overall structural integrity of the aircraft wing. A known rib includes a metal panel configured to be vertically oriented between the upper and lower skin panels of the aircraft wing, a first metal rib column, a second metal rib column, a first (e.g., upper) metal fitting, and a second (e.g., lower) metal fitting, wherein the metal panel is configured to be vertically oriented between the upper and lower skin panels of the aircraft wing, the first metal rib column is configured to couple the metal panel to the front spars of the aircraft wing, the second metal rib column is configured to couple the metal panel to the rear spars of the aircraft wing, the first (e.g., upper) metal fitting is configured to couple the metal panel to the upper skin panel of the aircraft wing, and the second (e.g., lower) metal fitting is configured to couple the metal panel to the lower skin panel of the aircraft wing. Current return network (CRN) cables can be coupled to the front and rear spars to facilitate carrying and / or dissipating electrical current and / or electrostatic charge away from the ribs and into the atmosphere.

[0003] The metal (e.g., aluminum) components of the known ribs described above typically have an increased cost-to-performance ratio and / or weight relative to the cost-to-performance ratio and / or weight of non-metallic structural materials (such as carbon fiber reinforced plastic (CFRP)) that may alternatively be used to construct such components of the ribs. Modifying the structure of the known ribs to include CFRP panels instead of metal panels can advantageously provide a rib having a relatively lower cost-to-performance ratio and / or weight. Summary of the invention

[0004] Example aircraft wing composite ribs with electrical ground paths are disclosed herein. In some examples, a composite rib is disclosed. In some disclosed examples, the composite rib includes a CFRP panel. In some disclosed examples, the composite rib further includes a metal rib column, which is coupled to the CFRP panel and configured to be coupled to a spar of an aircraft wing. In some disclosed examples, the spar is coupled to a CRN cable. In some disclosed examples, the composite rib further includes a metal fitting, which is coupled to the CFRP panel and configured to be coupled to a skin panel of the aircraft wing. In some disclosed examples, the composite rib further includes a metal grounding member, which is positioned between the CFRP panel and the metal fitting. In some disclosed examples, the metal grounding member provides an electrical grounding path extending from the metal fitting to the metal rib column.

[0005] In some examples, a method for assembling a composite rib is disclosed. In some disclosed examples, the method includes coupling a metal grounding member to a CFRP panel. In some disclosed examples, the method further includes coupling a metal rib column to the CFRP panel. In some disclosed examples, the metal rib column is configured to be coupled to a spar of an aircraft wing. In some disclosed examples, the spar is coupled to a CRN cable. In some disclosed examples, the method further includes coupling a metal fitting to the CFRP panel. In some disclosed examples, the metal fitting is configured to be coupled to a skin panel of the aircraft wing. In some disclosed examples of the method, the metal grounding member is positioned between the CFRP panel and the metal fitting, and the metal grounding member provides an electrical grounding path extending from the metal fitting to the metal rib column.

[0006] Also disclosed herein is an example metal fitting for coupling a composite rib to a skin panel of an aircraft wing. In some examples, a metal fitting configured to couple a composite rib to a skin panel of an aircraft wing is disclosed. In some disclosed examples, the metal fitting includes a through hole configured to receive a fastener. In some disclosed examples, the fastener is configured to couple the metal fitting to the composite rib. In some disclosed examples, the metal fitting further includes a hole configured to receive a bolt. In some disclosed examples, the metal fitting further includes a chamber intersecting with the hole. In some disclosed examples, the chamber has an access opening. In some disclosed examples, the metal fitting further includes a barrel nut located in the chamber. In some disclosed examples, the barrel nut is configured to threadably engage the bolt to couple the metal fitting to the skin panel. In some disclosed examples, the metal fitting further includes a seal located in the chamber. In some disclosed examples, the seal is configured to close the access opening.

[0007] In some examples, a method for coupling a composite rib to a skin panel of an aircraft wing via a metal fitting is disclosed. In some disclosed examples, the method includes extending a fastener through a through hole of the metal fitting to couple the metal fitting to the composite rib. In some disclosed examples, the method further includes extending a bolt into the hole of the metal fitting to couple the metal fitting to the skin panel. In some disclosed examples, the bolt threadingly engages a barrel nut located in a chamber of the metal fitting. In some disclosed examples, the chamber intersects the hole and has an access opening. In some disclosed examples, the access opening is closed by a seal located in the chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is an exploded view of an example composite rib constructed in accordance with the teachings of the present disclosure.

[0009] Figure 2 It is in assembled state Figure 1 A perspective view of an example of a composite rib.

[0010] Figure 3 is an example wing spar in an assembled state and coupled to an example aircraft wing Figure 1 and 2 A perspective view of an example of a composite rib.

[0011] Figure 4 is in an assembled state and is coupled to Figure 3 Example of an aircraft wing with skin panels Figure 1-3 Example of a cross-sectional view of a composite rib.

[0012] Figure 5 yes Figure 1-4 A perspective view of an example first metal fitting of an example composite rib.

[0013] Figure 6 is an exploded view of an example alternative composite rib constructed in accordance with the teachings of the present disclosure.

[0014] Figure 7 It is in assembled state Figure 6 An example of an alternative perspective view of a compound rib.

[0015] Certain examples are shown in the drawings identified above and described in detail below. In describing these examples, similar or identical reference numerals are used to identify the same or similar elements. The drawings are not necessarily drawn to scale, and certain features and certain views of the drawings may be shown exaggerated in scale or schematically for clarity and / or conciseness. DETAILED DESCRIPTION

[0016] As used herein in the context of describing a member, part or component of an apparatus, the term "structural" means that the member, part or component is a load-bearing member, part or component that is essential to the stability of the apparatus. For example, a structural member of a composite rib of an aircraft wing is a load-bearing component that is essential to the stability of the composite rib and / or the aircraft wing. In contrast, as used herein in the context of describing a member, part or component of an apparatus, the term "non-structural" means that a member, part or component is a non-load-bearing member, part or component that is not essential to the stability of the apparatus. For example, a non-structural member of a composite rib of an aircraft wing is a non-load-bearing component that is not essential to the stability of the composite rib and / or the aircraft wing.

[0017] A known rib includes a metal panel configured to be oriented vertically between upper and lower skin panels of an aircraft wing, a first metal rib post, a second metal rib post, a first (e.g., upper) metal fitting, and a second (e.g., lower) metal fitting, the metal panel being configured to be oriented vertically between upper and lower skin panels of an aircraft wing, the first metal rib post being configured to couple the metal panel to a front spar of the aircraft wing, the second metal rib post being configured to couple the metal panel to a rear spar of the aircraft wing, the first (e.g., upper) metal fitting being configured to couple the metal panel to an upper skin panel of the aircraft wing, and the second (e.g., lower) metal fitting being configured to couple the metal panel to a lower skin panel of the aircraft wing. The metal (e.g., aluminum) components of such ribs typically have an increased cost-to-performance ratio and / or weight relative to non-metallic structural materials (such as CFRP) that may be used to construct such components of the ribs instead. Modifying the structure of the known rib to include a CFRP panel in place of the metal panel can advantageously provide a rib having a relatively lower cost-to-performance ratio and / or weight.

[0018] Implementing a rib having a CFRP face sheet in place of a metal face sheet can also advantageously reduce thermally induced fatigue loads of the rib. For example, the coefficient of thermal expansion of CFRP is significantly lower than that of aluminum. When the rib includes an aluminum face sheet, a first (e.g., upper) aluminum fitting, and a second (e.g., lower) aluminum fitting, thermal contraction of the aluminum face sheet causes stretching relative to the first and / or second aluminum fittings. Replacing the aluminum face sheet of the rib with a CFRP face sheet creates a difference and / or mismatch in the coefficient of thermal expansion between the CFRP face sheet and the first and second aluminum fittings, thereby advantageously reducing the aforementioned stretching that would otherwise exist relative to the first and / or second aluminum fittings.

[0019] While implementing a composite rib with a CFRP panel can provide the advantages described above, implementing a CFRP panel in place of a corresponding metal panel can result in disadvantages with respect to lightning strike protection and / or dissipating electrostatic charge. For example, because CFRP is not a highly conductive material, implementing a composite rib with a CFRP panel in place of a corresponding metal (e.g., aluminum) panel can disrupt (e.g., eliminate) one or more electrical ground paths that would otherwise extend from a first (e.g., upper) metal fitting (e.g., an upper skin panel coupled to an aircraft) to a first metal rib post (e.g., a front spar coupled to an aircraft) and / or a second metal rib post (e.g., a rear spar coupled to an aircraft) in the presence of a metal panel, and / or from a second (e.g., lower) metal fitting (e.g., a lower skin panel coupled to an aircraft) to a first metal rib post (e.g., a front spar coupled to an aircraft) and / or a second metal rib post (e.g., a rear spar coupled to an aircraft). Disruption of the aforementioned electrical ground path(s) prevents electrical current and / or electrostatic charge from passing to the CRN cable(s) coupled to the front and rear spars, and thereby prevents carrying and / or dissipating such electrical current and / or electrostatic charge away from the composite rib.

[0020] The example aircraft wing composite rib disclosed herein advantageously includes a CFRP panel, a metal rib column, a metal fitting, and a metal grounding member (e.g., a metal grounding plate or a metal grounding cable). The metal rib column is coupled to the CFRP panel and is configured to be coupled to a spar of an aircraft wing, and the spar is coupled to a CRN cable. The metal fitting is coupled to the CFRP panel and is configured to be coupled to a skin panel of the aircraft wing. The metal grounding member is positioned between the CFRP panel and the metal fitting, thereby advantageously providing an electrical grounding path extending from the metal fitting to the metal rib column. The electrical grounding path enables current and / or electrostatic charge to be passed from the metal fitting to the metal rib column. The current and / or electrostatic charge can then be passed from the metal rib column to the CRN cable through the spar, thereby allowing such current and / or electrostatic charge to be transported and / or dissipated away from the composite rib and into the atmosphere. The electrical ground path formed by the metallic grounding members of the example aircraft wing composite ribs disclosed herein provides increased and / or improved lightning strike protection without compromising and / or interfering with the benefits described above associated with implementing a composite rib having CFRP panels in place of corresponding metal (e.g., aluminum) panels.

[0021] Figure 1 is an exploded view of an example composite rib 100 constructed in accordance with the teachings of the present disclosure. Figure 2 It is in assembled state Figure 1 1 is a perspective view of an example composite rib 100. Figure 3 is an example spar in an assembled state and coupled to an example aircraft wing 300 Figure 1 and Figure 2 A perspective view of an example of a composite rib. Figure 4 is in an assembled state and is coupled to Figure 3 Example skin panels of an aircraft wing 300 Figure 1-Figure 3 A cross-sectional view of an example composite rib 100 is shown. Figure 3 and Figure 4 As shown in FIG. 1 , aircraft wing 300 includes an example front spar 302 , an example rear spar 304 , an example first (eg, upper) skin panel 402 , and an example second (eg, lower) skin panel 404 . Figure 1-Figure 4 The composite rib 100 is configured to be coupled to the front and rear spars 302 , 304 and the upper and lower skin panels 402 , 404 of the aircraft wing 300 .

[0022] exist Figure 1-Figure 4In the illustrated example of , the composite rib 100 includes an example CFRP panel 102, an example hat-shaped reinforcement 104, an example metal grounding member and / or metal grounding plate 106, an example first (e.g., upper) metal fitting 108, an example second (e.g., lower) metal fitting 110, an example first (e.g., upper) fastener 112, and an example second (e.g., lower) fastener 114. As shown in Figure 3 As shown in Figure 1-Figure 4 The composite rib 100 further includes an example first metal rib column 306 and an example second metal rib column 308, wherein the first metal rib column 306 is configured to couple the composite rib 100 to the front spar 302 of the aircraft wing 300, and the second metal rib column 308 is configured to couple the composite rib 100 to the rear spar 304 of the aircraft wing 300.

[0023] As in Figure 1 As shown in Figure 1-Figure 4 The composite rib 100 includes three (3) hat reinforcements 104, three (3) first metal fittings 108, three (3) second metal fittings 110, twelve (12) first fasteners 112, and twelve (12) second fasteners 114. In other examples, the number of hat reinforcements 104, first metal fittings 108, second metal fittings 110, first fasteners 112, and / or second fasteners 114 can be different than in Figure 1 For example, the composite rib 100 can include any number (e.g., 1, 2, 4, 6, 12, etc.) of hat stiffeners 104, any number (e.g., 1, 2, 4, 6, 12, etc.) of first metal fittings 108, any number (e.g., 1, 2, 4, 6, 12, etc.) of second metal fittings 110, any number (e.g., 1, 2, 3, 6, 9, 24, etc.) of first fasteners 112, and / or any number (e.g., 1, 2, 3, 6, 9, 24, etc.) of second fasteners 114.

[0024] exist Figure 1-Figure 4 In the illustrated example, the number of hat reinforcements 104, the number of first metal fittings 108, and the number of second metal fittings 110 are equal to each other. In other examples, the number of hat reinforcements 104, the number of first metal fittings 108, and / or the number of second metal fittings 110 can be different from each other. Figure 1-4In the illustrated example, the number of first fasteners 112 is equal to the number of second fasteners 114, each of the first metal fittings 108 is configured to receive the same number (e.g., four) of the first fasteners 112, and each of the second metal fittings is configured to receive the same number (e.g., four) of the second fasteners 114. In other examples, the number of first fasteners 112 can be different from the number of second fasteners 114, respective ones of the first metal fittings 108 can be configured to receive different numbers of first fasteners 112 relative to each other, and / or respective ones of the second metal fittings can be configured to receive different numbers of second fasteners 114 relative to each other.

[0025] Figure 1-Figure 4 The CFRP panels 102 are structural and / or load-bearing components of the composite rib 100. Figure 1-Figure 4 In the illustrated example of , the CFRP panel 102 includes an example first surface 116, an example second surface 118 opposite the first surface 116 of the CFRP panel 102, an example first end 120, an example second end 122 opposite the first end 120 of the CFRP panel 102, a third (e.g., upper) surface 124 extending between the first and second ends 120, 122 of the CFRP panel 102, and a fourth (e.g., lower) surface 126 extending between the first and second ends 120, 122 of the CFRP panel 102 and opposite the third surface 124 of the CFRP panel 102. In some examples, the first surface 116 of the CFRP panel 102 is an inboard facing surface (e.g., facing and / or oriented toward a fuselage of an aircraft), and the second surface 118 of the CFRP panel 102 is an outboard facing surface (e.g., facing away and / or oriented away from a fuselage of an aircraft). In other examples, first surface 116 of CFRP panel 102 can be an outboard facing surface, and second surface 118 of CFRP panel 102 can be an inboard facing surface. In some examples, first end 120 of CFRP panel 102 is a forward facing end (e.g., facing and / or oriented toward a front spar and / or leading edge of a wing of an aircraft), and second end 122 of CFRP panel 102 is a rearward facing end (e.g., facing and / or oriented toward a rear spar and / or trailing edge of a wing of an aircraft). In other examples, first end 120 of CFRP panel 102 can be a rearward facing end, and second end 122 of CFRP panel 102 can be a forward facing end.

[0026] exist Figure 1-Figure 4In the illustrated example of , third surface 124 of CFRP panel 102 is configured to be oriented toward an upper and / or upward facing surface of example upper skin panel 402 of aircraft wing 300, and fourth surface 126 of CFRP panel 102 is configured to be oriented toward an lower and / or downward facing surface of example lower skin panel 404 of aircraft wing 300. Figure 1-Figure 4 , the third surface 124 of the CFRP panel 102 has a concave curvature between the first and second ends 120, 122 of the CFRP panel 102, and the fourth surface 126 of the CFRP panel 102 has an upward concave curvature between the first and second ends 120, 122 of the CFRP panel 102. In some examples, the concave curvature of the third surface 124 of the CFRP panel 102 can track, match, and / or complement the corresponding concave curvature of the upper skin panel 402 of the aircraft wing 300, and the upward concave curvature of the fourth surface 126 of the CFRP panel 102 can track, match, and / or complement the upward concave curvature of the lower skin panel 404 of the aircraft wing 300. In other examples, the third surface 124 and / or the fourth surface 126 of the CFRP panel 102 can have a concave curvature that is similar to that of the upper skin panel 404 of the aircraft wing 300. Figure 1-Figure 4 In some examples, third surface 124 and / or fourth surface 126 of CFRP panel 102 can be linear surfaces.

[0027] Figure 1-Figure 4 The CFRP panel 102 further includes an example center segment 128, an example first flange 130, and an example second flange 132. Figure 1-Figure 4 In the illustrated example, the boundaries of the central segment 128 of the CFRP panel 102 are formed and / or defined by the first and second ends 120, 122 and the third and fourth surfaces 124, 126 of the CFRP panel 102. The central segment 128 of the CFRP panel 102 defines an example plane 134 that extends and / or is vertically oriented between the upper and lower skin panels 402, 404 of the aircraft wing 300 when the composite rib 100 is coupled to the aircraft wing 300. As shown in Figure 1-Figure 4 As shown in FIG. 1 , the first flange 130 of the CFRP panel 102 is formed along and / or adjacent to the third surface 124 of the CFRP panel 102 , and the second flange 132 of the CFRP panel 102 is formed along and / or adjacent to the fourth surface 126 of the CFRP panel 102 .

[0028] exist Figure 1-Figure 4In the illustrated example of , the first and second flanges 130, 132 of the CFRP panel 102 are respectively formed as a continuous member extending between the first and second ends 120, 122 of the CFRP panel 102. In other examples, the first flange 130 and / or the second flange 132 of the CFRP panel 102 can alternatively be implemented as a plurality of flanges that are separated and / or spaced apart from each other. For example, the first flange 130 of the CFRP panel 102 can be implemented as a plurality of flanges that are spaced apart from each other and formed along and / or adjacent to the third surface 124 of the CFRP panel 102. As another example, the second flange 132 of the CFRP panel 102 can be implemented as a plurality of flanges that are spaced apart from each other and formed along and / or adjacent to the fourth surface 126 of the CFRP panel 102. In other examples, the first flange 130 and / or the second flange 132 can be omitted from the CFRP panel 102.

[0029] Figure 1-Figure 4 The first flange 130 of the CFRP panel 102 extends away from the central segment 128 of the CFRP panel 102 at an example first angle 136 relative to a plane 134 of the central segment 128, and Figure 1-Figure 4 The second flange 132 of the CFRP panel 102 extends away from the central segment 128 of the CFRP panel 102 at an example second angle 138 relative to the plane 134 of the central segment 128. Figure 1-Figure 4 In the illustrated example, the first and second angles 136, 138 are approximately equal to ninety degrees. In other examples, the first angle 136 and / or the second angle 138 can be a value greater than or less than ninety degrees (e.g., eighty degrees, one hundred degrees, etc.).

[0030] Figure 1-Figure 4 The CFRP panel 102 further includes an example first (e.g., upper) through hole 140 extending from the first surface 116 of the CFRP panel 102 to the second surface 118 of the CFRP panel 102 and an example second (e.g., lower) through hole 142 also extending from the first surface 116 of the CFRP panel 102 to the second surface 118 of the CFRP panel 102. As further described below, the first (e.g., upper) through hole 140 of the CFRP panel 102 is configured to receive a corresponding one of the first (e.g., upper) fasteners 112 to facilitate coupling the hat stiffener 104, the metal ground plate 106, and / or the first (e.g., upper) metal fitting 108 to the CFRP panel 102 of the composite rib 100. Similarly, the second (e.g., lower) through-hole 142 of the CFRP panel 102 is configured to receive a corresponding fastener of the second (e.g., lower) fastener 114 to facilitate coupling the hat reinforcement 104, the metal ground plate 106, and / or the second (e.g., lower) metal fitting 110 to the CFRP panel 102 of the composite rib 100.

[0031] The CFRP panel 102 can include any number of first (e.g., upper) through-holes 140 configured, positioned, and / or oriented to receive any corresponding number of first (e.g., upper) fasteners 112 and / or to align with any corresponding number of through-holes formed in the hat stiffener 104, the metal ground plate 106, and / or the first metal fitting 108 of the composite rib 100, respectively. Similarly, the CFRP panel 102 can include any number of second (e.g., lower) through-holes 142 configured, positioned, and / or oriented to receive any corresponding number of second (e.g., lower) fasteners 114 and / or to align with any corresponding number of through-holes formed in the hat stiffener 104, the metal ground plate 106, and / or the second metal fitting 110 of the composite rib 100, respectively.

[0032] Figure 1-Figure 4 The hat stiffeners 104 are structural and / or load-bearing members of the composite rib 100. In some examples, the hat stiffeners 104 can be CFRP hat stiffeners, and can accordingly be made of the same material as the CFRP panels 102 of the composite rib 100. In other examples, one or more of the hat stiffeners 104 can alternatively be made of a material other than CFRP, including, for example, a different plastic material and / or a metal material. Figure 1-Figure 4 In the illustrated example, each of the hat reinforcements 104 includes an example first (e.g., upper) end 144 and an example second (e.g., lower) end 146 located opposite the first end 144 of the hat reinforcement 104, a pair of example flanges 148 extending between the first and second ends 144, 146 of the hat reinforcement 104, and an example hat portion 150 extending between the first and second ends 144, 146 of the hat reinforcement 104 and bridging and extending away from the flanges 148 of the hat reinforcement 104. Figure 1-Figure 4 In the illustrated example, the first end 144 of each hat stiffener 104 is configured to be oriented toward an upper and / or upward facing end of an upper skin panel 402 of the aircraft wing 300, and the second end 146 of each hat stiffener 104 is configured to be oriented toward a lower and / or downward facing end of a lower skin panel 404 of the aircraft wing 300.

[0033] Figure 1-Figure 4The flange 148 of each hat reinforcement 104 includes an example first (e.g., upper) through-hole 152 extending through the flange 148 of the hat reinforcement 104 and an example second (e.g., lower) through-hole 154 extending through the flange 148 of the hat reinforcement 104. As further described below, the first (e.g., upper) through-hole 152 of each hat reinforcement 104 is configured to receive a corresponding fastener of the first (e.g., upper) fasteners 112 to facilitate coupling the hat reinforcement 104 to the CFRP panel 102 of the composite rib 100. Similarly, the second (e.g., lower) through-hole 154 of each hat reinforcement 104 is configured to receive a corresponding fastener of the second (e.g., lower) fasteners 114 to facilitate coupling the hat reinforcement 104 to the CFRP panel 102 of the composite rib 100.

[0034] The hat stiffener 104 can include any number of first (e.g., upper) through-holes 152 configured, positioned, and / or oriented to receive any corresponding number of first (e.g., upper) fasteners 112 and / or to align with any corresponding number of through-holes formed in the CFRP face sheet 102, the metal ground plate 106, and / or the first metal fitting 108 of the composite rib 100, respectively. Similarly, the hat stiffener 104 can include any number of second (e.g., lower) through-holes 154 configured, positioned, and / or oriented to receive any corresponding number of second (e.g., lower) fasteners 114 and / or to align with any corresponding number of through-holes formed in the CFRP face sheet 102, the metal ground plate 106, and / or the second metal fitting 110 of the composite rib 100, respectively.

[0035] when Figure 1-Figure 4 When the composite rib 100 is in an assembled state (e.g., Figure 2-Figure 4 ), the hat reinforcement 104 is coupled to the CFRP panel 102. In some examples, the hat reinforcement 104 is coupled to the CFRP panel 102 by bonding a flange 148 of the hat reinforcement 104 to the first surface 116 of the CFRP panel 102. In some examples, additionally or alternatively, the hat reinforcement 104 is coupled to the CFRP panel 102 by extending one or more first (e.g., upper) fasteners 112 through corresponding one or more first (e.g., upper) through-holes 140 of the CFRP panel 102 and through corresponding one or more first (e.g., upper) through-holes 152 of the hat reinforcement 104, and / or by extending one or more second (e.g., lower) fasteners 114 through corresponding one or more second (e.g., lower) through-holes 142 of the CFRP panel 102 and through corresponding one or more second (e.g., lower) through-holes 154 of the hat reinforcement 104.

[0036] exist Figure 2-Figure 4In the illustrated example, the flange 148 of each of the hat reinforcements 104 contacts the first surface 116 of the CFRP panel 102. Each of the hat reinforcements 104 is positioned along the first surface 116 of the CFRP panel 102 such that the first end 144 of the hat reinforcement 104 faces and / or is oriented toward the third surface 124 and / or the first flange 130 of the CFRP panel 102, and the second end 146 of the hat reinforcement 104 faces and / or is oriented toward the fourth surface 126 and / or the second flange 132 of the CFRP panel 102. Each of the hat reinforcements 104 is therefore located between the third and fourth surfaces 124, 126 of the CFRP panel 102 and / or between the first and second flanges 130, 132 of the CFRP panel 102.

[0037] Figure 1-Figure 4 The metal ground plate 106 is a non-structural and / or non-load bearing component of the composite rib 100. In some examples, the metal ground plate 106 can be made of aluminum, which is a highly conductive metal. In other examples, the metal ground plate 106 can alternatively be made of a metal material other than aluminum, including, for example, another highly conductive metal such as copper or nickel. Figure 1-Figure 4 In the illustrated example of , the metal ground plate 106 includes an example first surface 156, an example second surface 158 located opposite the first surface 156 of the metal ground plate 106, an example first end 160, an example second end 162 located opposite the first end 160 of the metal ground plate 106, a third (e.g., upper) surface 164 extending between the first and second ends 160, 162 of the metal ground plate 106, and a fourth (e.g., lower) surface 166 extending between the first and second ends 160, 162 of the metal ground plate 106 and located opposite the third surface 164 of the metal ground plate 106. The first surface 156 of the metal ground plate 106 faces and / or is oriented toward the second surface 118 of the CFRP panel 102. The second surface 158 of the metal ground plate 106 faces away from and / or is oriented away from the second surface of the CFRP panel 102 and toward the first and second metal fittings 108, 110. First end 160 of metal ground plate 106 faces and / or is oriented toward first end 120 of CFRP panel 102 , and second end 162 of metal ground plate 106 faces and / or is oriented toward second end 122 of CFRP panel 102 .

[0038] The third surface 164 of the metal ground plate 106 faces and / or is oriented toward the third surface 124 of the CFRP panel 102, and the fourth surface 166 of the metal ground plate 106 faces and / or is oriented toward the fourth surface 126 of the CFRP panel 102. Figure 1-Figure 4As shown in FIG. 1 , the third surface 164 of the metal ground plate 106 has a concave curvature between the first and second ends 160 , 162 of the metal ground plate 106 , and the fourth surface 166 of the metal ground plate 106 has an upward concave curvature between the first and second ends 160 , 162 of the metal ground plate 106 . Figure 1-4 In the illustrated example, the concave curvature of the third surface 164 of the metal ground plate 106 tracks, matches, and / or complements the concave curvature of the third surface 124 of the CFRP panel 102, and the concave curvature of the fourth surface 166 of the metal ground plate 106 tracks, matches, and / or complements the concave curvature of the fourth surface 126 of the CFRP panel 102. In other examples, the third surface 164 and / or the fourth surface 166 of the metal ground plate 106 can have a concave curvature that is similar to the concave curvature of the third surface 124 of the CFRP panel 102. Figure 1-Figure 4 In some examples, third surface 164 and / or fourth surface 166 of metal ground plate 106 can be linear surfaces.

[0039] Figure 1-Figure 4 The metal ground plane 106 further includes an example border 168 and an example opening 170. Figure 1-Figure 4 In the illustrated example of , a border 168 of the metal ground plate 106 surrounds an opening 170 of the metal ground plate 106. An outer border of the border 168 of the metal ground plate 106 is formed and / or defined by the first and second ends 160, 162 and the third and fourth surfaces 164, 166 of the metal ground plate 106. An inner border of the border 168 of the metal ground plate 106 is formed and / or defined by the opening 170. The opening 170 of the metal ground plate 106 extends from the first surface 156 of the metal ground plate 106 to the second surface 158 of the metal ground plate 106. The presence of the opening 170 reduces the overall weight of the metal ground plate 106 relative to alternative embodiments of the metal ground plate 106 that lack the opening 170. Figure 1-Figure 4 In the illustrated example, the opening 170 of the metal ground plate 106 is located between the first metal fitting 108 and the second metal fitting 110 of the composite rib 100 .

[0040] As combined below Figure 3 As further described, the border 168 and / or more generally the metal ground plate 106 provides a first electrical ground path extending from the first metal fitting 108 of the composite rib 100 to one or more exemplary metal rib posts of the composite rib 100, and further provides a second electrical ground path extending from the second metal fitting 110 of the composite rib 100 to one or more exemplary metal rib posts of the composite rib 100. As described below in conjunction with Figure 3 As further described, boundary 168 and / or more generally metal ground plate 106 connects the first electrical ground path to the second electrical ground path.

[0041] exist Figure 1-Figure 4 In the illustrated example of , the boundary 168 of the metal ground plate 106 has an elongated annular shape extending between the first and second ends 160, 162 and the third and fourth surfaces 164, 166 of the metal ground plate 106. In other examples, the boundary 168 and / or, more generally, the metal ground plate 106 can be implemented in different ways that still provide one or more electrical grounding paths extending from the first and / or second metal fittings 108, 110 of the composite rib 100 to one or more metal rib posts of the composite rib 100. For example, the boundary 168 and / or, more generally, the metal ground plate 106 can be constructed in a manner that omits the opening 170 from the metal ground plate 106. As another example, the boundary 168 and / or, more generally, the metal ground plate 106 can be constructed in a manner that provides a plurality (e.g., 2, 3, 10, 50, etc.) of openings in place of the first and / or second metal fittings 108, 110 of the composite rib 100. Figure 1-Figure 4 As another example, the boundary 168 and / or more generally the metal ground plate 106 can be constructed to have a non-annular shape. The boundary 168 and / or more generally the metal ground plate 106 can be constructed to have any shape (e.g., any regular or irregular shape) and / or any pattern (e.g., any regular or irregular pattern) that provides one or more electrical ground paths extending from the first and / or second metal fittings 108, 110 of the composite rib 100 to one or more metal rib posts of the composite rib 100.

[0042] Figure 1-Figure 4 The metal ground plate 106 of the composite rib 100 further includes an example first (e.g., upper) through-hole 172 extending from the first surface 156 of the metal ground plate 106 to the second surface 158 of the metal ground plate 106, and an example second (e.g., lower) through-hole 174 also extending from the first surface 156 of the metal ground plate 106 to the second surface 158 of the metal ground plate 106. As further described below, the first (e.g., upper) through-hole 172 of the metal ground plate 106 is configured to receive a corresponding fastener of the first (e.g., upper) fasteners 112 to facilitate coupling the metal ground plate 106 and / or the first (e.g., upper) metal fitting 108 to the CFRP panel 102 of the composite rib 100. Similarly, the second (e.g., lower) through-hole 174 of the metal ground plate 106 is configured to receive a corresponding fastener of the second (e.g., lower) fastener 114 to facilitate coupling the metal ground plate 106 and / or the second (e.g., lower) metal fitting 110 to the CFRP panel 102 of the composite rib 100.

[0043] The metal ground plate 106 can include any number of first (e.g., upper) through-holes 172 configured, positioned, and / or oriented to receive any corresponding number of first (e.g., upper) fasteners 112 and / or to align with any corresponding number of through-holes formed in the CFRP panel 102, the hat stiffener 104, and / or the first metal fitting 108 of the composite rib 100, respectively. Similarly, the metal ground plate 106 can include any number of second (e.g., lower) through-holes 174 configured, positioned, and / or oriented to receive any corresponding number of second (e.g., lower) fasteners 114 and / or to align with any corresponding number of through-holes formed in the CFRP panel 102, the hat stiffener 104, and / or the second metal fitting 110 of the composite rib 100, respectively.

[0044] when Figure 1-Figure 4 When the composite rib 100 is in an assembled state (e.g., Figure 2-Figure 4 ), the metal ground plate 106 is coupled to the CFRP panel 102. In some examples, the metal ground plate 106 is coupled to the CFRP panel 102 by bonding the first surface 156 of the metal ground plate 106 to the second surface 118 of the CFRP panel 102. In some examples, additionally or alternatively, the metal ground plate 106 is coupled to the CFRP panel 102 by extending one or more first (e.g., upper) fasteners 112 through corresponding one or more first (e.g., upper) through-holes 172 of the metal ground plate 106 and through corresponding one or more first (e.g., upper) through-holes 140 of the CFRP panel 102, and / or by extending one or more second (e.g., lower) fasteners 114 through corresponding one or more second (e.g., lower) through-holes 174 of the metal ground plate 106 and through corresponding one or more second (e.g., lower) through-holes 142 of the CFRP panel 102.

[0045] exist Figure 2-Figure 4 In the illustrated example of FIG. 1 , the metal ground plate 106 is positioned and / or located between the CFRP panel 102 and the first and second metal fittings 108, 110. The first surface 156 of the metal ground plate 106 contacts the second surface 118 of the CFRP panel 102. The first metal fitting 108 and the second metal fitting 110 are respectively positioned, located and / or arranged around the boundary 168 of the metal ground plate 106. The second surface 158 of the metal ground plate 106 contacts each of the first (e.g., upper) metal fitting 108 and each of the second (e.g., lower) metal fitting 110, thereby facilitating the connection between the metal ground plate 106 and the second metal fitting 110. Figure 3 The formation of an electrical ground path is shown in and described further below.

[0046] Figure 5 yes Figure 1-Figure 4A perspective view of an example first metal fitting 108 of an example composite rib 100 is shown. Figure 5 In the drawings, certain aspects of the first metal fitting 108 are shown transparently and / or in phantom to better enable observation of the components of the first metal fitting 108 . Figure 1-Figure 5 The first (e.g., upper) metal fittings 108 are structural and / or load-bearing members of the composite rib 100. In some examples, the first metal fittings 108 can be made of aluminum, which is a highly conductive metal. In other examples, one or more of the first metal fittings 108 can alternatively be made of a metal material other than aluminum, including, for example, another highly conductive metal such as copper or nickel. Figure 1-Figure 5 In the illustrated example of , each of the first metal fittings 108 includes an example plate portion 176 and an example rib portion 178 extending away from the plate portion 176 of the first metal fitting 108 .

[0047] Figure 1-Figure 5 The plate portion 176 of each first metal fitting 108 includes an example through-hole 180 extending through the plate portion 176 of the first metal fitting 108. As further described below, the through-hole 180 of each first metal fitting 108 is configured to receive a corresponding one of the first (e.g., upper) fasteners 112 to facilitate coupling the first metal fitting 108 to the CFRP panel 102 of the composite rib 100. The first metal fitting 108 can include any number of through-holes 180 configured, positioned, and / or oriented to receive any corresponding number of first (e.g., upper) fasteners 112, and / or to align with any corresponding number of through-holes correspondingly formed in the CFRP panel 102, hat stiffener 104, and / or metal ground plate 106 of the composite rib 100.

[0048] when Figure 1-Figure 4 When the composite rib 100 is in an assembled state (e.g., Figure 2-Figure 4 ), the first metal fitting 108 is coupled to the CFRP panel 102. In some examples, the first metal fitting 108 is coupled to the CFRP panel 102 by extending one or more first (e.g., upper) fasteners 112 through corresponding one or more through holes 180 of the first metal fitting 108, through corresponding one or more first (e.g., upper) through holes 172 of the metal ground plate 106, and through corresponding one or more first (e.g., upper) through holes 140 of the CFRP panel 102. Figure 2-Figure 4 In the illustrated example, each of the plate portions 176 of the first metal fittings 108 contacts the second surface 158 of the metal ground plate 106. Each of the first metal fittings 108 is disposed along the boundary 168 of the metal ground plate 106 to achieve Figure 3 The manner in which the electrical ground path is formed is shown in and described further below.

[0049] Figure 1-Figure 5 The rib portion 178 of each first metal fitting 108 includes an example hole 406 (eg, a blind hole) configured to receive an example first (eg, upper) bolt 408. Figure 1-Figure 5 In the illustrated example, the hole 406 does not extend completely through the rib portion 178. Figure 4 and Figure 5 As shown in FIG. 1 , the hole 406 of each first metal fitting 108 is oriented perpendicularly relative to the through hole 180 of the first metal fitting 108 . Figure 4 As shown in FIG. 4 , the first bolt 408 is configured to couple the first metal fitting 108 and / or more generally the composite rib 100 to the upper skin panel 402 of the aircraft wing 300 . Figure 1-5 The rib portion 178 of each first metal fitting 108 further includes an example cavity 410 having an example access opening 412. The cavity 410 of the first metal fitting 108 intersects with the aperture 406 of the first metal fitting 108. Figure 1-Figure 5 In the illustrated example, chamber 410 does not extend completely through rib portion 178. Figure 4 and Figure 5 As shown in FIG. 4 , the chamber 410 is configured to receive an example barrel nut 414 via an access opening 412 of the first metal fitting 108 . Figure 4 As shown in FIG. 4 , the barrel nut 414 of the first metal fitting 108 is positioned within the cavity 410 and is configured to threadingly engage the first bolt 408 to couple the first metal fitting 108 to the upper skin panel 402 of the aircraft wing 300 .

[0050] Figure 1-Figure 5 The rib portion 178 of each first metal fitting 108 further includes an exemplary seal 416 located within the cavity 410. Figure 4 and Figure 5 , the seal 416 of the first metal fitting 108 is configured to close and / or fill the access opening 412 of the chamber 410 once the barrel nut 414 has been positioned within the chamber 410 of the first metal fitting 108. In some examples, the seal 416 is configured to prevent sparks from exiting the chamber 410 through the access opening 412. In some examples, the seal 416 interfaces with fuel contained within the aircraft wing 300.

[0051] Figure 1-Figure 4The second (e.g., lower) metal fittings 110 are structural and / or load-bearing members of the composite rib 100. In some examples, the second metal fittings 110 can be made of aluminum, which is a highly conductive metal. In other examples, one or more of the second metal fittings 110 can alternatively be made of a metal material other than aluminum, including, for example, another highly conductive metal such as copper or nickel. Figure 1-Figure 4 In the illustrated example of , each of the second metal fittings 110 includes an example plate portion 182 and an example rib portion 184 extending away from the plate portion 182 of the second metal fitting 110 .

[0052] Figure 1-Figure 4 The plate portion 182 of each second metal fitting 110 includes an example first through-hole 186 extending through the plate portion 182 of the second metal fitting 110. As further described below, the first through-hole 186 of each second metal fitting 110 is configured to receive a corresponding one of the second (e.g., lower) fasteners 114 to facilitate coupling the second metal fitting 110 to the CFRP panel 102 of the composite rib 100. The second metal fitting 110 can include any number of first through-holes 186 configured, positioned, and / or oriented to receive any corresponding number of second (e.g., lower) fasteners 114, and / or to align with any corresponding number of through-holes correspondingly formed in the CFRP panel 102, hat stiffener 104, and / or metal ground plate 106 of the composite rib 100.

[0053] when Figure 1-Figure 4 When the composite rib 100 is in an assembled state (e.g., Figure 2-Figure 4 ), the second metal fitting 110 is coupled to the CFRP panel 102. In some examples, the second metal fitting 110 is coupled to the CFRP panel 102 by extending one or more second (e.g., lower) fasteners 114 through corresponding one or more first through holes 186 of the second metal fitting 110, through corresponding one or more second (e.g., lower) through holes 174 of the metal ground plate 106, and through corresponding one or more second (e.g., lower) through holes 142 of the CFRP panel 102. Figure 2-4 In the illustrated example, each of the plate portions 182 of the second metal fittings 110 contacts the second surface 158 of the metal ground plate 106. Each of the second metal fittings 110 is positioned along the boundary 168 of the metal ground plate 106 in a manner that enables the formation of an electrical ground path described below.

[0054] Figure 1-Figure 4 The rib portion 184 of each second metal fitting 110 includes an example second through hole 418 configured to receive an example second (eg, lower) bolt 420. Figure 1-4In the illustrated example of FIG. 1 , the second through hole 418 of each second metal fitting 110 is oriented perpendicularly relative to the first through hole 186 of the second metal fitting 110 . Figure 4 As shown in FIG. 4 , the second bolt 420 is configured to couple the second metal fitting 110 and / or more generally the composite rib 100 to the lower skin panel 404 of the aircraft wing 300. Figure 4 As further shown in FIG. 4 , an example retaining nut 422 is configured to threadingly engage a second bolt 420 to couple the second metal fitting 110 to the lower skin panel 404 of the aircraft wing 300 .

[0055] The first (e.g., upper) fastener 112 and the second (e.g., lower) fastener 114 can be implemented by and / or as any suitable type of threaded, partially threaded, and / or non-threaded fasteners, including, for example, bolts, screws, and / or rivets. Figure 1-4 When the composite rib 100 is in an assembled state (e.g., Figure 2-4 ), one or more first (e.g., upper) fasteners 112 extend through corresponding one or more through holes 180 of the first metal fitting 108, through corresponding one or more first (e.g., upper) through holes 172 of the metal ground plate 106, through corresponding one or more first (e.g., upper) through holes 140 of the CFRP panel 102, and through corresponding one or more first (e.g., upper) through holes 152 of the hat-shaped reinforcement 104, thereby coupling the first metal fitting 108, the metal ground plate 106, the CFRP panel 102, and the hat-shaped reinforcement 104 together. Similarly, one or more second (e.g., lower) fasteners 114 extend through corresponding one or more first through-holes 186 of the second metal fitting 110, through corresponding one or more second (e.g., lower) through-holes 174 of the metal ground plate 106, through corresponding one or more second (e.g., lower) through-holes 142 of the CFRP panel 102, and through corresponding one or more second (e.g., lower) through-holes 154 of the hat reinforcement 104, thereby coupling the second metal fitting 110, the metal ground plate 106, the CFRP panel 102, and the hat reinforcement 104 together.

[0056] exist Figure 1-Figure 4In the illustrated example of , the first metal fitting 108 is configured to couple the composite rib 100 to the upper skin panel 402 of the aircraft wing 300, and the second metal fitting 110 is configured to couple the composite rib 100 to the lower skin panel 404 of the aircraft wing 300. In other examples, this orientation can be reversed, with the first metal fitting 108 configured to couple the composite rib 100 to the lower skin panel 404 of the aircraft wing 300, and the second metal fitting 110 configured to couple the composite rib 100 to the upper skin panel 402 of the aircraft wing 300. In other examples, Figure 1-Figure 4 One or more second metal fittings 110 shown in FIG. 1 can be omitted, for example, to Figure 1-Figure 5 The first metal fitting 108 is similarly constructed and / or configured to be replaced by one or more replacement metal fittings. Figure 1-Figure 5 One or more first metal fittings 108 shown in FIG. 1 can be omitted, for example, to Figure 1-Figure 4 The second metal fitting 110 is constructed and / or configured in a similar manner to one or more replacement metal fittings.

[0057] exist Figure 1-Figure 4 In the illustrated example of , corresponding metal fittings in the first (eg, upper) metal fittings 108 are paired and / or vertically (vertically) aligned with corresponding metal fittings in the second (eg, lower) metal fittings 110. For example, Figure 1-Figure 4 The first metal fitting 108 includes an example first upper metal fitting 188 and an example second upper metal fitting 190 that is laterally spaced apart from the first upper metal fitting 188 . Figure 1-Figure 4 The second metal fitting 110 includes an example first lower metal fitting 192 and an example second lower metal fitting 194 that is laterally spaced apart from the first lower metal fitting 192. The first upper metal fitting 188 is paired with and / or vertically aligned with the first lower metal fitting 192. Similarly, the second upper metal fitting 190 is paired with and / or vertically aligned with the second lower metal fitting 194. Pairing and / or vertically aligning a corresponding metal fitting in the first metal fittings 108 with a corresponding corresponding metal fitting in the second metal fittings 110 advantageously enables the paired metal fittings in the first and second metal fittings 108, 110 to be coupled to a single and / or identical corresponding hat stiffener in the hat stiffener 104 of the composite rib 100. For example, as in Figure 4 As shown in FIG. 1 , the first upper metal fitting 188 and the first lower metal fitting 192 are commonly coupled to the Figure 1-Figure 4 The example first hat reinforcement 196 among the hat reinforcement 104 of the composite rib 100. Similarly, the second upper metal fitting 190 and the second lower metal fitting 194 can be commonly coupled to the Figure 1-Figure 4The example second hat stiffener 198 of the composite rib hat stiffener 104 is shown.

[0058] exist Figure 3 In the illustrated example of FIG. 1 , the composite rib 100 is shown in an assembled state and coupled to a front spar 302 and a rear spar 304 of an aircraft wing 300. A first metal rib post 306 couples the composite rib 100 to the front spar 302, and a second metal rib post 308 couples the composite rib 100 to the rear spar 304. An example first CRN cable 310 is supported by, coupled to, and / or mounted on the front spar 302, and an example second CRN cable 312 is supported by, coupled to, and / or mounted on the rear spar 304. The first and / or second CRN cables 310, 312 can lead to and / or be operably coupled to one or more discharge probes of the aircraft wing 300 that facilitate dissipating and / or discharging electrical current and / or electrostatic charge into the atmosphere.

[0059] Figure 3 The first metal rib post 306 is coupled (eg, screwed, riveted, etc.) to the CFRP panel 102 of the composite rib 100 at the first end 120 of the CFRP panel 102 . Figure 3 The second metal rib column 308 is coupled (e.g., screwed, riveted, etc.) to the CFRP panel 102 of the composite rib 100 at the second end 122 of the CFRP panel 102. When the composite rib 100 is coupled to the first and second metal rib columns 306, 308, as in Figure 3 As shown in FIG. 1 , the boundary 168 and / or more generally the metal ground plate 106 contacts the first and second metal fittings 108 , 110 and further contacts the first and second metal rib pillars 306 , 308 , thereby advantageously providing one or more electrical ground paths from the first and / or second metal fittings 108 , 110 to the first and / or second metal rib pillars 306 , 308 of the composite rib 100.

[0060] exist Figure 3 In the illustrated example of FIG. 1 , the boundary 168 and / or more generally the metal ground plate 106 provides an example first electrical ground path 314 extending from one or more of the first metal fittings 108 to the first and / or second metal ribs 306, 308. The boundary 168 and / or more generally the metal ground plate 106 further provides an example second electrical ground path 316 extending from one or more of the second metal fittings 110 to the first and / or second metal ribs 306, 308. As shown in FIG. Figure 3 As shown in FIG. 1 , the boundary 168 of the metal ground plate 106 connects the first and second electrical ground paths 314 , 316 to each other.

[0061] Electrical current (eg, lightning current from a lightning strike) and / or electrostatic charge can be received at the first and / or second metal fittings 108 , 110 of the composite rib 100 from the first and / or second skin panels 402 , 404 of the aircraft wing 300 . Figure 3 The first and / or second electrical grounding paths 314, 316 are capable of conveying and / or conducting received electrical current and / or electrostatic charge from the first and / or second metal fittings 108, 110 of the composite rib 100 to the first and / or second metal rib posts 306, 308 of the composite rib 100. The electrical current and / or electrostatic charge received at the first metal rib post 306 is conducted from the first metal rib post 306 to the first CRN cable 310 through the front spar 302. The electrical current and / or electrostatic charge received at the second metal rib post 308 is conducted from the second metal rib post 308 to the second CRN cable 312 through the rear spar 304. The first and / or second CRN cables 310, 312 convey and / or conduct the electrical current and / or electrostatic charge to one or more discharge probes of the aircraft wing 300 that facilitate dissipation and / or discharge of the electrical current and / or electrostatic charge into the atmosphere. Thus, the first and second electrical ground paths 314 , 316 of the composite rib 100 advantageously help carry, transmit, and / or divert electrical current and / or electrostatic charge away from the composite rib 100 and into the atmosphere.

[0062] exist Figure 4 In the illustrated example of FIG. 1 , the composite rib 100 is shown in an assembled state and coupled to an upper skin panel 402 and a lower skin panel 404 of an aircraft wing 300. The hat stiffener 104 is coupled to the CFRP panel 102. The flange 148 of the hat stiffener 104 contacts the first surface 116 of the CFRP panel 102. The metal ground plate 106 is coupled to the CFRP panel 102. The first surface 156 of the metal ground plate 106 contacts the second surface 118 of the CFRP panel 102. The first (e.g., upper) metal fitting 108 is coupled to the CFRP panel 102. The plate portion 176 of the first metal fitting 108 contacts the second surface 158 of the metal ground plate 106. The second (e.g., lower) metal fitting 110 is coupled to the CFRP panel 102. The plate portion 182 of the second metal fitting 110 contacts the second surface 158 of the metal ground plate 106. The first (e.g., upper) fastener 112 extends through the plate portion 176 of the first metal fitting 108, through the metal ground plate 106, through the CFRP panel 102, and through one of the flanges 148 of the hat reinforcement 104. The second (e.g., lower) fastener 114 extends through the plate portion 182 of the second metal fitting 110, through the metal ground plate 106, through the CFRP panel 102, and through one of the flanges 148 of the hat reinforcement 104.

[0063] exist Figure 4In the illustrated example of FIG. 1 , the assembled composite rib 100 is coupled to an upper skin panel 402 of an aircraft wing 300 via a first (e.g., upper) metal fitting 108, and is coupled to a lower skin panel 404 of the aircraft wing 300 via a second (e.g., lower) metal fitting 110. The coupling of the assembled composite rib 100 to the upper skin panel 402 of the aircraft wing 300 via the first metal fitting 108 is provided in part by a threaded engagement between a first bolt 408 and a barrel nut 414. The coupling of the assembled composite rib 100 to the lower skin panel 404 of the aircraft wing 300 via the second metal fitting 110 is provided in part by a threaded engagement between a second bolt 420 and a retaining nut 422.

[0064] The electric current (e.g., lightning current) and / or electrostatic charge applied to the upper skin panel 402 of the aircraft wing 300 is transferred from the upper skin panel 402 to the first (e.g., upper) metal fitting 108 of the composite rib 100, through the metal ground plate 106 (e.g., via Figure 3 The first electrical ground path 314 of the composite rib 100 is transferred from the first metal fitting 108 to the first and / or second metal rib posts 306, 308, and from the first and / or second metal rib posts 306, 308 to the first and / or second CRN cables 310, 312 through the front and / or rear spars 302, 304. The electrical current and / or electrostatic charge applied to the lower skin panel 404 of the aircraft wing 300 is transferred from the lower skin panel 404 to the second (e.g., lower) metal fitting 110 of the composite rib 100, through the metal ground plate 106 (e.g., via the Figure 3 The second electrical ground path 316 of the first and / or second metal ribs 306, 308 is transferred from the second metal fitting 110 and transferred from the first and / or second metal ribs 306, 308 to the first and / or second CRN cables 310, 312 through the front and / or rear spars 302, 304. The current and / or electrostatic charge received by the first and / or second CRN cables 310, 312 is carried and / or transmitted to one or more discharge probes of the aircraft wing 300 that facilitate dissipation and / or discharge of the current and / or electrostatic charge into the atmosphere.

[0065] Figure 6 is an exploded view of an example alternative composite rib 600 constructed in accordance with the teachings of the present disclosure. Figure 7 It is in assembled state Figure 6 A perspective view of an example alternative composite rib 600 is shown. Figure 6 and Figure 7 Alternative composite ribs 600 include those described above. Figure 1-Figure 5The composite rib 100 includes a CFRP panel 102 , a hat reinforcement 104 , a metal ground plate 106 , a first (eg, upper) metal fitting 108 , a second (eg, lower) metal fitting 110 , a first (eg, upper) fastener 112 , and a second (eg, lower) fastener 114 . Figure 6 and Figure 7 The alternative composite rib 600 can be obtained by Figure 3 The corresponding metal ribs in the first and second metal ribs 306 and 308 are connected to Figure 1-4 The composite rib 100 is as described above via Figure 3 The corresponding metal ribs in the first and second metal ribs 306, 308 are coupled to Figure 3 The front and rear spars 302, 304 of the aircraft wing 300 are coupled to the Figure 3 The front and rear spars 302, 304 of the aircraft wing 300. In addition, Figure 6 and Figure 7 The alternative composite rib 600 can be used with Figure 1-Figure 4 The composite rib 100 is coupled to the Figure 4 The upper skin panel 402 and the lower skin panel 404 of the aircraft wing 300 are coupled to the Figure 4 An upper skin panel 402 and a lower skin panel 404 of an aircraft wing 300 are shown.

[0066] In addition to the components and / or parts identified above, Figure 6 and Figure 7 The alternative composite rib 600 further includes an example first (eg, upper) shear link 602 and an example second (eg, lower) shear link 604. Figure 6 and Figure 7 In the illustrated example of , the alternative composite rib 600 includes two (2) first shear links 602 and two (2) second shear links 604. In other examples, the alternative composite rib 600 can include a different number (e.g., 0, 1, 3, etc.) of first shear links 602, and / or a different number (e.g., 0, 1, 3, etc.) of second shear links 604. Figure 6 and Figure 7 The first and second shear links 602, 604 are structural and / or load-bearing members that replace the composite rib 600. In some examples, the first and second shear links 602, 604 can be CFRP shear links, and can be made of the same material as the CFRP panel 102 that replaces the composite rib 600. In other examples, one or more of the first and second shear links 602, 604 can be made of materials other than CFRP, including, for example, different plastic materials and / or metal materials.

[0067] Respective ones of the first (e.g., upper) shear links 602 are configured to be coupled to the metal ground plate 106 between adjacent ones of the first (e.g., upper) metal fittings 108 of the alternative composite rib 600. Similarly, respective ones of the second (e.g., lower) shear links 604 are configured to be coupled to the metal ground plate 106 between adjacent ones of the second (e.g., lower) metal fittings 110 of the alternative composite rib 600. For example, as in Figure 7 , an example first upper shear link 606 from among the first (e.g., upper) shear links 602 is coupled (e.g., bonded) to the second surface 158 of the metal ground plate 106 at a location between the first upper metal fitting 188 and the second upper metal fitting 190 from among the first (e.g., upper) metal fittings 108 from the alternative composite rib 600. As shown in Figure 7 As further shown in FIG. 1 , an example first lower shear link 608 from among the second (e.g., lower) shear links 604 is coupled (e.g., bonded) to the second surface 158 of the metal ground plate 106 at a location between the first lower metal fitting 192 and the second lower metal fitting 194 from among the second (e.g., lower) metal fitting 110 from the alternative composite rib 600. Figure 1-Figure 4 Composite rib 100, Figure 6 and Figure 7 The first and second shear links 602 , 604 of the alternative composite rib 600 advantageously improve the overall stability of the alternative composite rib 600 without compromising and / or hindering the benefits provided by the first and second electrical grounding paths 514 , 516 , which remain fully operational in the alternative composite rib 600 .

[0068] In light of the foregoing, it will be appreciated that an example aircraft wing composite rib having an electrical ground path has been disclosed. The disclosed composite rib advantageously includes a CFRP panel, a metal rib column, a metal fitting, and a metal grounding member (e.g., a metal grounding plate or a metal grounding cable). The metal rib column is coupled to the CFRP panel and is configured to be coupled to a spar of an aircraft wing, and the spar is coupled to a CRN cable. The metal fitting is coupled to the CFRP panel and is configured to be coupled to a skin panel of the aircraft wing. The metal grounding member is positioned between the CFRP panel and the metal fitting, thereby advantageously providing an electrical grounding path extending from the metal fitting to the metal rib column. The electrical grounding path enables current and / or electrostatic charge to be passed from the metal fitting to the metal rib column. The current and / or electrostatic charge can thereafter be passed from the metal rib column to the CRN cable through the spar, thereby allowing such current and / or electrostatic charge to be transported and / or dissipated away from the composite rib and into the atmosphere. The electrical ground path formed by the metallic grounding members of the example aircraft wing composite ribs disclosed herein provides increased and / or improved lightning strike protection without compromising and / or interfering with the benefits described above associated with implementing a composite rib having CFRP panels in place of corresponding metal (e.g., aluminum) panels.

[0069] In some examples, a composite rib is disclosed. In some disclosed examples, the composite rib includes a CFRP panel. In some disclosed examples, the composite rib further includes a metal rib column, which is coupled to the CFRP panel and configured to be coupled to a spar of an aircraft wing. In some disclosed examples, the spar is coupled to a CRN cable. In some disclosed examples, the composite rib further includes a metal fitting, which is coupled to the CFRP panel and configured to be coupled to a skin panel of the aircraft wing. In some disclosed examples, the composite rib further includes a metal grounding member, which is positioned between the CFRP panel and the metal fitting. In some disclosed examples, the metal grounding member provides an electrical grounding path extending from the metal fitting to the metal rib column.

[0070] In some disclosed examples, the electrical ground path is configured to carry lightning current from the metal fitting to the metal rib. In some disclosed examples, the lightning current is to be received from the skin panel at the metal fitting, pass through the electrical ground path, and pass from the metal rib to the CRN cable through the spar.

[0071] In some disclosed examples, the electrical ground path is configured to carry electrostatic charge from the metal fitting to the metal rib. In some disclosed examples, the electrostatic charge is to be received from the skin panel at the metal fitting, passed through the electrical ground path, and passed from the metal rib to the CRN cable through the spar.

[0072] In some disclosed examples, the metallic grounding member is a non-structural member.

[0073] In some disclosed examples, the metal fitting is a first metal fitting, the skin panel is an upper skin panel, and the electrical ground path is a first electrical ground path. In some disclosed examples, the composite rib further includes a second metal fitting, the second metal fitting is coupled to the CFRP panel. In some disclosed examples, the metal grounding member is further disposed between the CFRP panel and the second metal fitting. In some disclosed examples, the metal grounding member provides a second electrical grounding path extending from the second metal fitting to the metal rib column.

[0074] In some disclosed examples, the metal grounding member is a metal grounding plate.

[0075] In some disclosed examples, the metal ground plate includes a border and an opening surrounded by the border. In some disclosed examples, the opening is located between the first and second metal fittings. In some disclosed examples, the first and second metal fittings contact the border. In some disclosed examples, the border connects the first and second electrical ground paths.

[0076] In some disclosed examples, the metal ground plate includes a first surface and a second surface located opposite the first surface. In some disclosed examples, the first surface contacts the CFRP panel. In some disclosed examples, the second surface contacts the first and second metal fittings.

[0077] In some disclosed examples, the composite rib further includes a hat reinforcement coupled to the CFRP panel.

[0078] In some disclosed examples, the CFRP panel includes a first surface and a second surface located opposite the first surface. In some disclosed examples, the hat reinforcement contacts the first surface of the CFRP panel, and the metal ground plate contacts the second surface of the CFRP panel.

[0079] In some disclosed examples, the hat reinforcement is bonded to the first surface of the CFRP panel. In some disclosed examples, the metal ground plate is bonded to the second surface of the CFRP panel.

[0080] In some disclosed examples, the CFRP panel further includes a central segment, a first flange, and a second flange, the central segment defining a plane, the first flange extending away from the central segment at a first angle relative to the plane, and the second flange extending away from the central segment at a second angle relative to the plane. In some disclosed examples, the hat reinforcement is located between the first flange and the second flange.

[0081] In some disclosed examples, the composite rib further comprises a first fastener extending through the first metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement. In some disclosed examples, the composite rib further comprises a second fastener extending through the second metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement.

[0082] In some disclosed examples, the first metal fitting is a first upper metal fitting, and the second metal fitting is a first lower metal fitting. In some disclosed examples, the composite rib further includes a second upper metal fitting, the second upper metal fitting is coupled to the CFRP panel and is configured to be coupled to the upper skin panel, the second upper metal fitting is spaced apart from the first upper metal fitting. In some disclosed examples, the composite rib further includes a second lower metal fitting, the second lower metal fitting is coupled to the CFRP panel and is configured to be coupled to the lower skin panel, the second lower metal fitting is spaced apart from the first lower metal fitting. In some disclosed examples, the composite rib further includes a first shear connector, the first shear connector is coupled to the metal ground plate at a position between the first and second upper metal fittings. In some disclosed examples, the composite rib further includes a second shear connector, the second shear connector is coupled to the metal ground plate at a position between the first and second lower metal fittings.

[0083] In some examples, a method for assembling a composite rib is disclosed. In some disclosed examples, the method includes coupling a metal grounding member to a CFRP panel. In some disclosed examples, the method further includes coupling a metal rib column to the CFRP panel. In some disclosed examples, the metal rib column is configured to be coupled to a spar of an aircraft wing. In some disclosed examples, the spar is coupled to a CRN cable. In some disclosed examples, the method further includes coupling a metal fitting to the CFRP panel. In some disclosed examples, the metal fitting is configured to be coupled to a skin panel of the aircraft wing. In some disclosed examples of the method, the metal grounding member is positioned between the CFRP panel and the metal fitting, and the metal grounding member provides an electrical grounding path extending from the metal fitting to the metal rib column.

[0084] In some disclosed examples, the metal fitting is a first metal fitting, the skin panel is an upper skin panel, and the electrical ground path is a first electrical ground path. In some disclosed examples, the method further includes coupling a second metal fitting to the CFRP panel. In some disclosed examples, the second metal fitting is configured to be coupled to a lower skin panel of the aircraft wing. In some disclosed examples, the metal grounding member is further disposed between the CFRP panel and the second metal fitting, and the metal grounding member provides a second electrical grounding path extending from the second metal fitting to the metal rib.

[0085] In some disclosed examples, the metal grounding member is a metal grounding plate.

[0086] In some disclosed examples, the metal ground plate includes a border and an opening surrounded by the border. In some disclosed examples, the opening is located between the first and second metal fittings. In some disclosed examples, the first and second metal fittings contact the border. In some disclosed examples, the border connects the first and second electrical ground paths.

[0087] In some disclosed examples, the method further includes coupling a hat reinforcement to the CFRP panel.

[0088] In some disclosed examples, the CFRP panel includes a first surface and a second surface located opposite the first surface. In some disclosed examples, the hat reinforcement contacts the first surface of the CFRP panel, and the metal ground plate contacts the second surface of the CFRP panel.

[0089] In some disclosed examples, coupling the hat reinforcement to the CFRP panel includes bonding the hat reinforcement to the first surface of the CFRP panel. In some disclosed examples, coupling the metal ground plate to the CFRP panel includes bonding the metal ground plate to the second surface of the CFRP panel.

[0090] In some disclosed examples, coupling the first metal fitting to the CFRP panel includes extending a first fastener through the first metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement. In some disclosed examples, coupling the second metal fitting to the CFRP panel includes extending a second fastener through the second metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement.

[0091] In some examples, a metal fitting configured to couple a composite rib to a skin panel of an aircraft wing is disclosed. In some disclosed examples, the metal fitting includes a through hole configured to receive a fastener, the fastener being configured to couple the metal fitting to the composite rib. In some disclosed examples, the metal fitting further includes a hole configured to receive a bolt. In some disclosed examples, the metal fitting further includes a chamber intersecting the hole, the chamber having an access opening. In some disclosed examples, the metal fitting further includes a barrel nut located within the chamber, the barrel nut being configured to threadably engage the bolt to couple the metal fitting to the skin panel. In some disclosed examples, the metal fitting further includes a seal located within the chamber, the seal being configured to close the access opening.

[0092] In some disclosed examples, the through hole is perpendicular to the hole.

[0093] In some disclosed examples, the metal fitting further includes a plate portion and a rib portion extending away from the plate portion.

[0094] In some disclosed examples, the through hole is formed in the plate portion.

[0095] In some disclosed examples, the hole is formed in the rib portion. In some disclosed examples, the hole does not extend completely through the rib portion.

[0096] In some disclosed examples, the cavity is formed in the rib portion. In some disclosed examples, the cavity does not extend completely through the rib portion.

[0097] In some disclosed examples, the seal is configured to prevent sparks from exiting the chamber through the entry opening.

[0098] In some disclosed examples, the seal is configured to interface with fuel contained within a wing of the aircraft.

[0099] In some examples, a method for coupling a composite rib to a skin panel of an aircraft wing via a metal fitting is disclosed. In some disclosed examples, the method includes extending a fastener through a through hole of the metal fitting to couple the metal fitting to the composite rib. In some disclosed examples, the method further includes extending a bolt into the hole of the metal fitting to couple the metal fitting to the skin panel. In some disclosed examples, the bolt threadingly engages a barrel nut located in a chamber of the metal fitting. In some disclosed examples, the chamber intersects the hole and has an access opening. In some disclosed examples, the access opening is closed by a seal located in the chamber.

[0100] In some disclosed examples of the method, the through hole is perpendicular to the hole.

[0101] In some disclosed examples of the method, the metal fitting includes a plate portion and a rib portion extending away from the plate portion.

[0102] In some disclosed examples of the method, the through hole is formed in the plate portion.

[0103] In some disclosed examples of the method, the hole is formed in the rib portion. In some disclosed examples, the hole does not extend completely through the rib portion.

[0104] In some disclosed examples of the method, the cavity is formed in the rib portion. In some disclosed examples, the cavity does not extend completely through the rib portion.

[0105] In some disclosed examples of the method, the seal is configured to prevent sparks from exiting the chamber through the access opening.

[0106] In some disclosed examples of the method, the seal is configured to interface with fuel contained within a wing of the aircraft.

[0107] Although certain example methods, apparatus, and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture that fully fall within the scope of the claims of this patent.

Claims

1. A composite rib (100, 600), comprising: Carbon fiber reinforced plastic panel, i.e. CFRP panel (102); a metal rib (306, 308) coupled to the CFRP panel and configured to be coupled to a spar (302, 304) of an aircraft wing (300), the spar being coupled to a current return network cable (CRN cable) (310, 312); a metal fitting coupled to the CFRP panel and configured to be coupled to a skin panel of the aircraft wing; as well as A metal grounding member is positioned between the CFRP panel and the metal fitting, the metal grounding member providing an electrical grounding path extending from the metal fitting to the metal rib.

2. The composite rib according to claim 1, wherein the electrical grounding path is configured to carry a lightning current or an electrostatic charge from the metal fitting to the metal rib column, the lightning current or the electrostatic charge to be received from the skin panel at the metal fitting, pass through the electrical grounding path, and be transmitted from the metal rib column to the CRN cable through the spar.

3. The composite rib according to claim 1 or 2, wherein the metal grounding member is a non-structural member.

4. The composite rib of claim 1, wherein the metal fitting is a first metal fitting (108), the skin panel is an upper skin panel (402), and the electrical ground path is a first electrical ground path (314), wherein the composite rib further comprises a second metal fitting (110), the second metal fitting (110) is coupled to the CFRP panel and is configured to be coupled to a lower skin panel (404) of the aircraft wing, wherein the metal grounding member is further disposed between the CFRP panel and the second metal fitting, the metal grounding member providing a second electrical grounding path (316) extending from the second metal fitting to the metal rib column, and wherein the metal grounding member is a metal grounding plate.

5. The composite rib of claim 4, wherein the metal ground plate comprises a boundary (168) and an opening (170) surrounded by the boundary, the opening being located between the first metal fitting and the second metal fitting, the first metal fitting and the second metal fitting contacting the boundary, the boundary connecting the first electrical ground path and the second electrical ground path, and wherein the metal ground plate comprises a first surface (156) and a second surface (158) located opposite the first surface, the first surface contacting the CFRP panel, and the second surface contacting the first metal fitting and the second metal fitting.

6. The composite rib according to claim 4, further comprising a hat-shaped reinforcement (104), the hat-shaped reinforcement (104) being coupled to the CFRP panel, wherein the CFRP panel includes a first surface (116) and a second surface (118) located opposite to the first surface, the hat-shaped reinforcement contacts the first surface of the CFRP panel, and the metal ground plate contacts the second surface of the CFRP panel.

7. The composite rib of claim 6, wherein the hat stiffener is bonded to the first surface of the CFRP panel and the metal ground plate is bonded to the second surface of the CFRP panel, and wherein the CFRP panel further comprises a center segment (128), a first flange (130), and a second flange (132), the center segment (128) defining a plane (134), the first flange (130) extending away from the center segment at a first angle (136) relative to the plane, the second flange (132) extending away from the center segment at a second angle (138) relative to the plane, and wherein the hat stiffener is located between the first flange and the second flange.

8. The composite rib according to claim 6 or 7, further comprising: a first fastener (112) extending through the first metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement; and A second fastener (114) extends through the second metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement.

9. The composite rib according to any one of claims 4 to 7, wherein the first metal fitting is a first upper metal fitting (188), and the second metal fitting is a first lower metal fitting (192), the composite rib further comprising: a second upper metal fitting (190) coupled to the CFRP panel and configured to be coupled to the upper skin panel, the second upper metal fitting being spaced apart from the first upper metal fitting; a second lower metal fitting (194) coupled to the CFRP panel and configured to be coupled to the lower skin panel, the second lower metal fitting being spaced apart from the first lower metal fitting; a first shear link (606) coupled to the metal ground plate at a location between the first upper metal fitting and the second upper metal fitting; as well as A second shear link (608) is coupled to the metal ground plate at a location between the first lower metal fitting and the second lower metal fitting.

10. A method for assembling a composite rib (100, 600), the method comprising: coupling a metal grounding member to a carbon fiber reinforced plastic (CFRP) panel (102); coupling metal ribs (306, 308) to the CFRP panels, the metal ribs being configured to be coupled to spars (302, 304) of an aircraft wing (300), the spars being coupled to current return network cables (CRN cables) (310, 312); as well as coupling a metal fitting to the CFRP panel, the metal fitting being configured to be coupled to a skin panel of a wing of the aircraft; The metal grounding member is positioned between the CFRP panel and the metal fitting, the metal grounding member providing an electrical grounding path extending from the metal fitting to the metal rib.

11. The method of claim 10, wherein the metal accessory is a first metal accessory (108), the skin panel is an upper skin panel (402), and the electrical ground path is a first electrical ground path (314), wherein the method further comprises coupling a second metal accessory (110) to the CFRP panel, the second metal accessory being configured to be coupled to a lower skin panel (404) of the aircraft wing, wherein the metal grounding member is further positioned between the CFRP panel and the second metal accessory, the metal grounding member providing a second electrical grounding path (316) extending from the second metal accessory to the metal rib, and wherein the metal grounding member is a metal ground plate.

12. The method of claim 11, wherein the metal ground plate comprises a border (168) and an opening (170) surrounded by the border, the opening being located between the first metal fitting and the second metal fitting, the first metal fitting and the second metal fitting contacting the border, the border connecting the first electrical ground path and the second electrical ground path.

13. The method of claim 11, further comprising coupling a hat reinforcement (104) to the CFRP panel, wherein the CFRP panel includes a first surface (116) and a second surface (118) located opposite the first surface, the hat reinforcement contacts the first surface of the CFRP panel, and the metal ground plate contacts the second surface of the CFRP panel.

14. The method of claim 13, wherein coupling the hat reinforcement to the CFRP panel comprises bonding the hat reinforcement to the first surface of the CFRP panel, and wherein coupling the metal ground plate to the CFRP panel comprises bonding the metal ground plate to the second surface of the CFRP panel.

15. The method of claim 13 or 14, wherein coupling the first metal fitting to the CFRP panel comprises extending a first fastener (112) through the first metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement, and wherein coupling the second metal fitting to the CFRP panel comprises extending a second fastener (114) through the second metal fitting, the metal ground plate, the CFRP panel, and the hat reinforcement.

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