Aircraft equipped with a transparent wall attached to a structure by a shock-absorbing system
The use of sacrificial energy-absorbing pads in the fastening system of aircraft transparent walls addresses the challenge of impact energy absorption, enabling thinner and lighter designs that withstand bird strikes effectively.
Patent Information
- Application Number
- FR2024006768
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2025-12-26
AI Technical Summary
Existing aircraft transparent walls, such as windshields and windows, are not effectively designed to absorb impact energy from bird strikes while maintaining structural integrity and weight efficiency.
Aircraft transparent walls are attached to a supporting structure using a fastening system with sacrificial energy-absorbing pads that deform plastically to absorb impact energy, allowing for thinner and potentially lighter walls.
The system enhances the ability of transparent walls to withstand bird strikes by absorbing energy, either elastically or plastically, while enabling the use of lighter materials and potentially handling more violent impacts.
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Abstract
Description
Title of the invention: Aircraft equipped with a transparent wall attached to a structure by a shock-absorbing system
[0001] The present invention relates to an aircraft equipped with a transparent wall fixed to a structure by an anti-shock system.
[0002] An aircraft conventionally comprises at least one transparent wall allowing an aircraft occupant to see the outside environment. For example, a transparent wall may be made from poly(methyl methacrylate), or may take the form of a multilayer glass-based wall, or even a multi-material wall, or other materials.
[0003] According to prior art, a transparent wall can be glued and / or screwed to a load-bearing structure of the aircraft. Alternatively, the transparent wall can be arranged in a frame which is glued and / or screwed to such a load-bearing structure.
[0004] A transparent partition may, in particular, be an element of a windshield or a window oriented according to the forward movement of an aircraft. Such a transparent partition is liable to be exposed to impacts, particularly in flight with a bird.
[0005] In the event of collisions with a bird, it is essentially the transparent wall that participates in the absorption of the energy resulting from the impact in the presence of a transparent wall screwed and / or glued to a load-bearing structure, directly or via a frame.
[0006] The transparent walls are then dimensioned to withstand the impacts of birds according to the requirements of the certification regulations.
[0007] Document CA3066586 Al suggests making a windshield with several different transparent walls to avoid replacing the entire windshield in case of destructive impacts with a bird.
[0008] US patent 2017 / 0129587 A1 proposes attaching a windshield to a supporting structure using metal or composite straps. The straps are independent and screwed to the edges of the windshield. The straps are intended to reduce or prevent cracking, breakage, damage to the supporting structure, or separation of the windshield.
[0009] Document US2016 / 0264230 A1 describes a windshield having a first thickness and a second, different thickness.
[0010] The present invention then aims to provide an aircraft equipped with a transparent wall attached to a supporting structure in an innovative way, for example to be able to use a lightweight transparent wall.
[0011] The invention relates to an aircraft equipped with a transparent wall interposed between an internal environment located in the aircraft and an external environment, the transparent wall being fixed to a supporting structure of the aircraft by a fixing system, the transparent wall having an internal face facing the internal environment and an external face facing the external environment.
[0012] The fastening system includes at least one sacrificial energy-absorbing pad, said energy-absorbing pad comprising at least one energy absorber secured, for example directly or indirectly via an intermediate piece, to the transparent wall and the supporting structure, said at least one energy absorber comprising an internal absorber mechanically connected at least to the inner face.
[0013] The internal absorber is mechanically connected to the inner face, namely fixed directly or indirectly via at least one other connecting element to the inner face, but is not necessarily connected to the outer face of the transparent wall. A possible external absorber, described subsequently and distinct from the internal absorber, may, on the other hand, be mechanically connected at least to the outer face, either directly or indirectly via an intermediate element.
[0014] The transparent surface may be a surface likely to be impacted by a bird during forward flight. For example, the transparent surface may be a windshield or a porthole.
[0015] Therefore, this transparent wall is attached to the supporting structure, not simply by glue, rivets and / or screws or even a frame, but by means of one or more plastically deformable energy-absorbing pads.
[0016] In the event of a bird strike, the transparent wall deforms. If the impact occurs at low speed and / or with a bird of low mass, for example, the transparent wall can absorb the resulting energy, the energy-absorbing buffer(s) possibly deforming elastically.
[0017] However, in the event of a significant impact, this deformation induces plastic deformation of one or more sacrificial energy absorbers. The term "sacrificial" refers to this irreversible plastic deformation. This energy absorber or these energy absorbers thus absorb a portion of the energy resulting from the impact. Upon the aircraft's return, the energy-absorbing pad(s) can be replaced during a maintenance operation.
[0018] Compared to a conventional aircraft, the invention then makes it possible to implement potentially thinner transparent walls, and therefore lighter ones to withstand the same impact with a bird in flight, and / or can make it possible to withstand a more violent impact.
[0019] The aircraft may also include one or more of the following characteristics, taken alone or in combination.
[0020] According to one possibility, the internal absorber can be fixed to the transparent wall directly or by a frame.
[0021] Thus, the internal absorber can be glued and / or screwed, or even riveted, to the transparent wall so as to be attached to the inner face. A deformation of the transparent wall can then generate a force acting on the internal absorber.
[0022] Alternatively, the transparent wall can be attached to a frame, with the internal absorber fixed to this frame. For example, the frame is glued to the transparent wall, and the internal absorber can be glued and / or screwed, or even riveted, to the frame. This variant can, for example, avoid drilling through the transparent wall.
[0023] According to a possibility compatible with the preceding ones, the internal absorber can be fixed to the supporting structure or to an internal support fixed to the supporting structure.
[0024] The term "support" hereafter refers to a structural element, such as a plate, possibly bent, capable of mechanically connecting two parts. A support may be part of a frame.
[0025] Thus, the internal absorber can be fixed directly to the supporting structure, for example by gluing and / or screwing and / or riveting. Fixing by gluing has the advantage of not requiring drilling of the internal absorber.
[0026] Alternatively, the internal absorber can be indirectly attached to the supporting structure. In this case, the internal absorber can be attached to an internal support, for example, by bonding and / or screwing and / or riveting. This internal support is then attached to the supporting structure, also for example by bonding and / or screwing and / or riveting. This alternative has the advantage of allowing the internal absorber to be fully mounted outside the aircraft, and the internal support to be attached to the supporting structure during an assembly phase.
[0027] According to a possibility compatible with the preceding ones, said at least one energy absorber may include an external absorber mechanically connected at least to the external face and fixed to the supporting structure or to an external support fixed to the supporting structure.
[0028] In this case, the energy absorber may comprise two absorbers on either side of the transparent wall to optimize energy absorption, particularly in two opposite directions. When the transparent wall deforms following an impact, one of the two internal and external absorbers may deform initially, with the other absorber deforming subsequently.
[0029] The external absorber can be fixed directly to the supporting structure, for example by gluing and / or screwing and / or riveting. Fixing by gluing has the advantage of not requiring drilling of the external absorber.
[0030] Alternatively, the external absorber can be indirectly attached to the supporting structure. In this case, the external absorber can be attached to an external support, for example, by bonding and / or screwing and / or riveting. This external support is further attached to the supporting structure, also for example by bonding and / or screwing and / or riveting. This alternative has the advantage of allowing the external absorber to be mounted entirely outside the aircraft, and the external support to be attached to the supporting structure only during an assembly phase.
[0031] The external absorber can be attached directly to the transparent wall, for example by gluing and / or screwing and / or riveting, or indirectly, for example by means of the aforementioned frame. Optionally, the external absorber can be glued and / or screwed, or even riveted, to the transparent wall so as to be attached to its outer surface. A deformation of the transparent wall can then generate a force acting on the external absorber.
[0032] In the presence of an energy-absorbing pad equipped with both an internal absorber and an external absorber, said internal absorber and said external absorber of the same energy-absorbing pad can be symmetrical with respect to the transparent wall.
[0033] The internal absorber and the external absorber may be identical. Alternatively, they may be different, namely of different shape and / or dimensions, depending on the stresses to be withheld.
[0034] Optionally, when the internal absorber is fixed to the internal support and the external absorber is fixed to the external support, the aircraft may include a frame comprising the external support and the internal support.
[0035] The transparent wall can be pre-equipped by being attached to a frame via the energy-absorbing pad(s). The frame is then attached to the supporting structure in the usual way.
[0036] According to a possibility consistent with the preceding ones, generally two energy absorbers can be different, namely of different shapes and / or dimensions, whether these energy absorbers are of the internal or external type. The characteristics of two energy absorbers can, for example, vary depending on their location.
[0037] For example, the fixing system may include at least two so-called energy absorbers having different stiffnesses along the same axis, and for example along an axis perpendicular to the transparent wall.
[0038] According to another aspect, an energy absorber, whether an internal or external absorber, can be made according to various variants.
[0039] According to a possibility compatible with the preceding ones and a first variant, at least one energy absorber may comprise a z-shaped structure equipped with two end sections connected by an internal section, one of the end sections being attached to the transparent wall directly or by a frame and the other end section being attached to the supporting structure, directly or indirectly as described above.
[0040] Such a z-structure has the advantage of being plastically deformable when stressed along two axes, and in two opposite directions per axis.
[0041] According to a possibility compatible with the previous ones and a second variant, at least one energy absorber may comprise a honeycomb structure.
[0042] A honeycomb structure comprises cells which extend along an axis substantially perpendicular locally to the transparent wall.
[0043] The cells of this structure can then deform, by crushing, to absorb part of the energy resulting from an impact with the transparent wall.
[0044] According to a possibility compatible with the preceding ones and a third variant, at least one energy absorber may comprise at least one deformable organ in the form of a truncated hollow sphere, the deformable organ extending from a circular arc base to a vertex, said base being connected to the transparent wall.
[0045] Optionally, a deformable element includes a base attached to the base. The base may be in the shape of a portion of a disc or a disc, and is attached to the transparent wall.
[0046] A spherical organ may be shaped like a hemisphere, a quarter-sphere, or other shapes. When a base is present, this base may be disc-shaped in the case of a hemispherical spherical organ, or a half-disk in the case of a quarter-sphere spherical organ. The spherical organs can then deform, by collapsing, to absorb some of the energy resulting from an impact with the transparent wall.
[0047] It should be noted that an energy-absorbing pad can be equipped with different internal and external absorbers. For example, the internal and external absorbers of the same pad can belong to the same variant but have different dimensional characteristics. As another example, the internal and external absorbers of the same pad can be made according to different variants.
[0048] According to a possibility compatible with the preceding ones, the fastening system may comprise a single energy-absorbing pad extending continuously over an edge of the transparent wall.
[0049] The energy-absorbing pad then extends along a closed line around the periphery of the transparent wall to be subjected to stress regardless of the impact zone. Different sections of the pad can form different energy absorbers; for example, two different sections can have different stiffnesses along the same axis.
[0050] According to a possibility compatible with the preceding ones, the fastening system may comprise several energy-absorbing pads spaced apart along an edge of the transparent wall.
[0051] Several energy-absorbing pads are then positioned along the periphery of the transparent wall so that at least one energy-absorbing pad is activated regardless of the impact zone. At least two energy-absorbing pads may be different, featuring absorbers of different variants and / or having different dimensions. The energy-absorbing pads can be adapted according to the estimated energy to be dissipated in order to optimize the installation, particularly from a mass perspective.
[0052] The invention and its advantages will become apparent in more detail in the following description, with illustrative examples given by reference to the accompanying figures, which represent:
[0053] [Fig. 1], a front view of an aircraft according to the invention,
[0054] [Fig. 2], a diagram showing a fastening system according to the invention,
[0055] [Fig. 3], a diagram showing a fastening system having a single pad energy absorbing,
[0056] [Fig. 4], a diagram showing a fastening system having several energy-absorbing pads,
[0057] [Fig. 5], a diagram showing an energy-absorbing buffer having an internal absorber fixed directly to the supporting structure,
[0058] [Fig. 6], a diagram showing an energy-absorbing buffer having an internal absorber indirectly attached to the supporting structure,
[0059] [Fig. 7], a diagram showing an energy-absorbing pad having an internal absorber indirectly attached to the transparent wall,
[0060] [Fig.8], a diagram showing an energy-absorbing buffer having an external absorber indirectly attached to the supporting structure,
[0061] [Fig.9], a diagram showing an energy-absorbing buffer having an external absorber fixed directly to the supporting structure,
[0062] [Fig. 10], a diagram showing an energy-absorbing pad having an external absorber indirectly attached to the transparent wall,
[0063] [Fig. 1 1], a diagram showing an energy absorber having a Z-shaped structure,
[0064] [Fig. 12], a diagram showing an energy absorber having a nest-like structure of bees, and
[0065] the [Fig. 13], a diagram showing an energy absorber having a structure equipped with at least one hollow spherical organ.
[0066] Elements present in several separate figures are assigned one and the same reference.
[0067] Figure 1 shows an aircraft 1 according to the invention. This aircraft 1 comprises at least one transparent wall 10 supported by a load-bearing structure 5. Such a transparent wall 10 is interposed between an internal environment located in the aircraft 1 and an external environment EXT. According to Figure 2, the transparent wall 10 then extends along its thickness from an internal face 11 facing the internal environment INT to an external face 12 facing the external environment EXT.
[0068] The transparent wall(s) 10 are likely to be impacted by a bird during flight, particularly when the aircraft 1 is moving forward at high speed.
[0069] According to the invention, a transparent wall 10 is fixed to the supporting structure 5 by a fixing system 20 allowing to absorb at least part of the energy resulting from an impact with a bird by plastic deformation.
[0070] Figure [Fig. 2] illustrates such a fastening system 20 according to the invention.
[0071] This fastening system 20 comprises at least one sacrificial energy-absorbing pad 30. [Fig. 3] illustrates the possibility of having a single energy-absorbing pad 31 extending continuously along an edge 15 of the transparent wall 10. Conversely, [Fig. 4] illustrates the possibility of having several energy-absorbing pads 32-37 spaced apart along this edge 15.
[0072] Reference "30" designates any energy-absorbing buffer, references 31 to 37 designate specific energy-absorbing buffers if required.
[0073] With reference to [Fig.2] and regardless of the number of energy-absorbing pads 30, an energy-absorbing pad 30 according to the invention comprises at least one sacrificial energy absorber 39 which is attached directly or indirectly to the transparent wall 10 and to the supporting structure 5. Different sections of an energy-absorbing pad can form different energy absorbers, for example of different stiffnesses.
[0074] Consequently, when a bird strikes the transparent wall 10 in the direction of arrow F, the transparent wall 10 can deform, for example, following a waveform illustrated with dashed lines. In the presence of an impact generating low energy, the transparent wall 10 deforms elastically and returns to its initial state. Optionally, an energy-absorbing pad 30 can deform elastically. In the presence of an impact generating high energy, at least one energy-absorbing pad 30 deforms plastically and thus absorbs some of the energy resulting from the impact. The term "sacrificial" refers to such plastic deformation. The term "sacrificial" can also be used to describe the energy absorber(s).
[0075] At a minimum, and with reference to [Fig. 5], an energy-absorbing pad comprises an internal absorber 39 40 connected to the inner face 11. As shown in [Fig. 5], the internal absorber 40 is attached to the inner face 11. The internal absorber 40 can be fixed to the transparent wall 10, for example, by gluing and / or screwing and / or riveting, and possibly by being glued to the inner face 11.
[0076] In addition, the internal absorber 40 is fixed directly or indirectly to the supporting structure 5.
[0077] According to [Fig.5], the internal absorber 40 is fixed directly to the supporting structure 5 by gluing and / or screwing and / or riveting for example.
[0078] According to [Fig. 6], the internal absorber 40 is attached to an internal support 61, for example by gluing and / or screwing and / or riveting. The internal support 61 is then attached to the supporting structure 5, for example by gluing and / or screwing and / or riveting. This internal support 61 may include at least one plate shaped to connect the internal absorber 40 to the supporting structure 5. For example, this internal support 61 is part of a frame 63 that encloses the edge 15 of the transparent wall 10.
[0079] According to the example in [Fig.7], the internal absorber 40 is mechanically connected indirectly to the inner face 11. In particular, a frame 64 is attached to the edge 15 of the transparent wall 10, the internal absorber 40 being fixed to this frame 64. The internal absorber 40 can then be fixed to the supporting structure 5 either directly according to the illustrated example or via an internal support according to a variant not illustrated so as not to unnecessarily multiply the figures.
[0080] Optionally, and with reference to Figures 8 to 10, an energy-absorbing pad 30 may include an external absorber 50 connected to the external face 2. The internal absorber 40 and the external absorber 50 of the same energy-absorbing pad 30 are located on either side of the transparent wall 10 and may be identical or different. The internal absorber 40 and the external absorber 50 of the same energy-absorbing pad 30 may be symmetrical with respect to the transparent wall 10.
[0081] For example, the external absorber 50 can be fixed to the transparent wall 10 directly, for example by gluing and / or screwing and / or riveting, and possibly by being glued to the external face 12, or indirectly via a frame which encloses the edge 15 of the transparent wall 10, for example.
[0082] In addition, the external absorber 50 is fixed directly or indirectly to the supporting structure 5.
[0083] According to [Fig. 8], the external absorber 50 is attached to an external support 62, for example by bonding and / or screwing and / or riveting. The external support 62 is then attached to the supporting structure 5, for example by bonding and / or screwing and / or riveting. This external support 62 may include at least one plate shaped to connect the external absorber 50 to the supporting structure 5. For example, this external support 62 is part of a frame 63 that encloses the edge 15 of the transparent wall 10, this frame 63 also including the internal support 61.
[0084] The internal absorber 40 can be attached to the inner face directly, as illustrated, or via a frame. Furthermore, the internal absorber 40 can be attached to the supporting structure directly or via an internal support 61, as illustrated. The internal support 61 can be part of a frame 63 that encloses the edge 15.
[0085] According to [Fig. 9], the external absorber 50 is fixed directly to the supporting structure 5 by gluing and / or screwing and / or riveting. The internal absorber 40 can be fixed to the inner face directly as illustrated or via a frame. Furthermore, the internal absorber 40 can be fixed to the supporting structure directly as illustrated or via an internal support 61.
[0086] According to the example of [Fig.10] the internal absorber 40 and the external absorber of the same pad 50 are fixed to a frame 64 which encloses the edge 15 of the transparent wall.
[0087] Figures 11 to 13 illustrate various possible variants of energy absorbers. Although these figures 11 to 13 illustrate an energy-absorbing pad 30 having an identical internal absorber 40 and external absorber 50, it is obviously possible to have different internal absorbers 40 and external absorbers 50 within a single energy-absorbing pad 30, or even to have no external absorber 50 at all. Although these figures 11 to 13 illustrate an energy-absorbing pad 30 having an internal absorber 40 and an external absorber 50 fixed directly to the transparent wall 10 and to a frame 63, it is obviously possible to have internal absorbers 40 and external absorbers 50 fixed indirectly or directly to the transparent wall 10 and to the supporting structure 5 in accordance with the various examples mentioned above.
[0088] According to [Fig. 1 1], at least one energy absorber 39 comprises a z-shaped structure 71. This z-shaped structure 71 is thus provided with two substantially parallel end sections 72, 73, connected by an oblique internal section 74. One of the end sections 72 is then fixed, or even attached, to the transparent wall 10, and the other end section 73 is fixed, or even attached, to the supporting structure 5 or to a support 71, 72.
[0089] According to [Fig. 12], at least one energy absorber 39 comprises a honeycomb structure 75. A honeycomb structure 75 comprises cells extending in a direction substantially perpendicular locally to the transparent wall 10.
[0090] According to [Fig. 13], at least one energy absorber 39 has at least one hollow spherical element 76, and in particular three spherical elements according to the examples. Each spherical element has the shape of a truncated sphere. Thus, each spherical element extends from a base 77 describing an arc of a circle to a vertex 78. The base 77 is then connected to the transparent wall 10, for example by bonding. The vertex 78 is, conversely, fixed to the supporting structure 5 or to a support 61, 62. In addition, a deformable element may include a base 79 integral with the base 77.
[0091] Naturally, the present invention is subject to numerous variations in its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible embodiments. It is, of course, conceivable to replace a described means with an equivalent means without departing from the scope of the present invention as defined by the claims.
[0092] For example, although Figures 3 and 4 illustrate buffers having only internal absorbers, at least one of the buffers may also have an external absorber.
[0093] It is also possible to add to the realization of [Fig.7] an external absorber fixed to the frame 64 or to the external face 12.
[0094] According to another example, a fastening system comprises at least two different energy absorbers, for example, with different stiffnesses along the same axis. By way of illustration, two energy-absorbing pads according to [Fig. 4] have two energy absorbers of the same shape but with different stiffnesses, for example, through different local thicknesses. According to another example, the pad in [Fig. 3] comprises two sections forming two energy absorbers of the same shape but with different stiffnesses.
Claims
Demands
1. Aircraft (1) equipped with a transparent wall (10) interposed between an internal environment (INT) located in the aircraft (1) and an external environment (EXT), the transparent wall (10) being fixed to a supporting structure (5) of the aircraft (1) by a fastening system (20), the transparent wall (10) having an internal face (11) with regard to the internal environment (INT) and an external face (12) with regard to the external environment (EXT), characterized in that the fastening system (20) comprises at least one sacrificial energy-absorbing pad (30), said energy-absorbing pad (30) comprising at least one energy absorber (39) attached to the transparent wall (10) and to the supporting structure (5), said at least one energy absorber (40, 50) comprising an internal absorber (40) mechanically connected at least to the internal face (11).
2. Aircraft according to claim 1, characterized in that the internal absorber (40) is fixed to the carrier structure (5) or to an internal support (61) fixed to the carrier structure (5).
3. Aircraft according to any one of claims 1 to 2, characterized in that the internal absorber (40) is fixed to the transparent wall (10) directly or by a frame (64).
4. Aircraft according to any one of claims 1 to 3, characterized in that said at least one energy absorber comprises an external absorber (50) mechanically connected at least to the external face (12) and fixed to the carrier structure (5) or to an external support (62) fixed to the carrier structure (5).
5. Aircraft according to claim 4, characterized in that said internal absorber (40) and said external absorber (50) of the same energy-absorbing pad (30) are symmetrical with respect to the transparent wall (10).
6. Aircraft according to claim 2 and any one of claims 4 to 5, characterized in that the internal absorber (40) being fixed to the internal support (61) and the external absorber (50) being fixed to the external support (62), the aircraft (1) comprises a frame (63) including the external support (62) and the internal support (61).
7. Aircraft according to any one of claims 1 to 6, characterized in that the fastening system (20) comprises at least two said energy absorbers (39) having different stiffnesses about the same axis.
8. Aircraft according to any one of claims 1 to 7, characterized in that at least one energy absorber (390) comprises a z-shaped structure (71) having two end sections (72, 73) connected by an internal section (74), one of the end sections (72) being attached to the transparent wall (10) directly or by a frame (64), and the other end section being attached to the supporting structure (5).
9. Aircraft according to any one of claims 1 to 8, characterized in that at least one energy absorber (39) has a honeycomb structure (75).
10. Aircraft according to any one of claims 1 to 9, characterized in that at least one energy absorber (39) has at least one deformable element (76) in the form of a truncated hollow sphere, the deformable element (76) extending from a circular arc base (77) to a vertex (78), said base (77) being connected to the transparent wall (10).
11. Aircraft according to any one of claims 1 to 10, characterized in that the fastening system (20) comprises a single energy-absorbing pad (31) extending continuously over an edge (15) of the transparent wall (10).
12. Aircraft according to any one of claims 1 to 10, characterized in that the fastening system (20) comprises several energy-absorbing pads (32-37) spaced apart along an edge (15) of the transparent wall (10).
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