Metal and composite tube comprising damping foam

Abstract

The invention relates to a metal and composite tube (4) which comprises a first tube (6) made of metal material, a second tube made of composite material and a damping stack (8). The damping stack (8) is located inside the first tube (6) and the second tube. The damping stack (8) comprises at least a first stage (80) of damping foam and a second stage (80) of damping foam which are separated from one another by a transverse wall (84) made of composite material.

Description

METAL AND COMPOSITE TUBE INCLUDING DAMPING FOAM Technical field of the invention

[0001] The invention relates to the field of manufacturing structural tubes, in particular for vehicles. More specifically, it relates to a metal and composite tube. In particular, the metal and composite tube is part of a chassis of the vehicle and is designed to protect people inside the vehicle from injury in the event of an accident. The vehicle is, for example, a light aircraft such as a tourist plane or an ultra-light powered aircraft, also known as a "ULM". State of the prior art

[0002] The frames of current light land and air vehicles are generally made of metal. These metallic materials are often heavy. For legal and environmental reasons, the mass of vehicles tends to decrease, mainly to limit the pollution generated by these vehicles.

[0003] Materials lighter than metals and their alloys are being developed and used. Composite materials are known for their low mass and mechanical strength. However, composite materials are rarely used in the chassis of land or air motor vehicles due to the low maximum plastic deformation of these materials and the risk of sudden breakage of these materials, generating fragments that are dangerous for people nearby in the event of an accident.

[0004] Safety requirements for people on board vehicles are also becoming more stringent, particularly so that the vehicle can effectively protect these people in the event of an accident. Vehicle safety requirements are also difficult to reconcile with vehicle mass reduction requirements, which tend to reduce the maximum amount of energy that the vehicle can absorb in the event of an accident without injuring the people on board.

[0005] Metallic and composite tubes have recently been developed for automotive and aeronautical use, as illustrated for example by the IEE Access publication, “Crashworthiness Analuses and Design of Metal / CFRP hybrid structures under lateral loading,” authored by Guohua Zhu, Xuan Zhao, Peilong Shi, and Qiang Yu, which was published on May 30, 2019. These metallic and composite tubes have made it possible to increase the mechanical strength of tubes, while limiting the mass and size of the tubes.

[0006] There is a need to further increase the mechanical strength of a tube, while limiting the mass and bulk of the tube. In particular, there is a need to improve the safety of a driver, a pilot and / or passengers inside a vehicle in the event of an accident, while limiting the mass and bulk of the vehicle.

[0007] The invention aims to remedy all or part of the drawbacks of the state of the art mentioned above.

[0008] In this regard, the invention relates to a metal and composite tube, in particular for a land and / or air vehicle. The metal and composite tube comprises a first tube made of metal material and a second tube made of composite material.

[0009] According to the invention, the metal and composite tube comprises a damping stack inside the first tube and the second tube. The damping stack comprises at least a first stage of damping foam and a second stage of damping foam which are separated from each other by a transverse wall made of composite material.

[0010] Thanks to the metal and composite tube according to the invention, the mechanical strength of a tube is increased, while limiting the mass and size of the tube. The safety of a pilot, a driver and / or passengers is notably improved, while limiting the mass and size of a vehicle comprising the metal and composite tube. The manufacture of the metal and composite tube is relatively easy. In particular, the damping stack is relatively easy to manufacture.

[0011] In particular, the safety of people inside the vehicle is improved, since the metal and composite tube absorbs a large amount of energy during a vehicle accident, while deforming in a controlled manner, avoiding injury to people during the deformation of the tube. The metal material of the first tube, the composite material of the second tube and the damping stack, and the damping foam provide maximum energy absorption that is greater than the sum of the maximum energy absorbed by the metal material, by that absorbed by each composite material, and by that absorbed by each damping foam, while controlling the deformation of the metal and composite tube.

[0012] The metallic material of the first tube protects the damping foam and the composite material of the second tube and / or the damping stack, in particular from radiation, mechanical shocks and humidity. The metallic material deforms gradually by deforming plastically until rupture. By deforming more gradually, the metallic material helps to control the deformation of the composite material and the damping foam. The risk of sudden breakage of the composite material is limited, which would for example be likely to injure people in the vehicle. The risks of deterioration of the foam are limited, in particular by promoting elastic deformation of the foam.

[0013] The composite material has high resistance to deformation and impact, especially compared to the metallic material. Cracks in the composite material are accompanied by plastic deformation of the metallic material. The composite material allows for a reduction in the mass and size of the tubes.

[0014] The shock-absorbing foam is configured to deform elastically, absorbing impact energy. It quickly and easily absorbs energy in the event of an accident. The shock-absorbing foam absorbs, in particular, the energy of impacts of limited intensity. The maximum amplitude of deformation of the foam is reduced by each transverse wall and by the second tube, which limits damage to the foam, for example, tearing of the foam. The foam effectively absorbs energy, while limiting the mass and bulk of the tubes.

[0015] According to a particular embodiment, the first tube envelops the second tube while being located outside the second tube. The second tube envelops the damping stack while being located outside the damping stack.

[0016] According to another embodiment feature, the metal and composite tube is cylindrical with a circular cross-section. The first tube is cylindrical with a circular cross-section. The second tube is cylindrical with a circular cross-section. The damping stack is cylindrical with a circular cross-section.

[0017] According to a particular embodiment, the shock-absorbing foam comprises a closed-cell solid foam. Preferably, the shock-absorbing foam is a cross-linked polymer foam suitable for a land and / or air vehicle.

[0018] According to another embodiment feature, the composite material of the second tube and / or the transverse wall comprises a matrix and reinforcing fibers. The matrix comprises at least one resin chosen from at least one polyepoxide, one polyester and one polyetherketone. The reinforcing fibers comprise at least one element chosen from carbon fibers, glass fibers and aramid fibers.

[0019] According to a particular embodiment, each transverse wall is made of the same composite material as the composite material of the second tube.

[0020] According to another embodiment feature, the composite material comprises a polyepoxide and carbon fibers.

[0021] According to a particular embodiment, the first tube made of metallic material is made of a metallic material which comprises aluminum and / or titanium. Preferably, the first tube is made of a titanium alloy.

[0022] According to another embodiment feature, the damping stack comprises at least three stages of damping foam. Two consecutive stages of damping foam are separated by a transverse wall made of composite material.

[0023] According to a particular embodiment, the shock-absorbing foam stages of the shock-absorbing stack are identical in pairs.

[0024] According to another embodiment feature, the metal and composite tube comprises at least two damping stacks inside the first tube and the second tube. Each damping stack comprises at least a first stage of damping foam and a second stage of damping foam which are separated from each other by a transverse wall made of composite material.

[0025] According to a particular embodiment, the metal and composite tube comprises damping stacks joined in the longitudinal direction of the metal and composite tube.

[0026] According to another embodiment feature, a damping foam stage of one of the damping stacks is different from a damping foam stage of another of the damping stacks.

[0027] According to a particular embodiment, the second tube is segmented along the longitudinal direction of the composite and mechanical tube, each segment of the second tube having a length identical to the length of one of the damping stacks along the longitudinal direction of the composite and mechanical tube.

[0028] The invention also relates to a method for manufacturing a metal and composite tube as defined above. The manufacturing method comprises a step of manufacturing the damping stack by stacking at least two stages of damping foam separated by a transverse wall made of composite material. The manufacturing method comprises a step of manufacturing the second tube around the damping stack. The manufacturing method comprises a step of inserting the damping stack and the second tube inside the first tube.

[0029] According to a particular embodiment, the damping stack is manufactured by stacking damping foam stages which are separated by transverse walls made of composite material, and by cutting the damping foam and each transverse wall to the shape of the first tube and / or the second tube.

[0030] According to another particular embodiment, the second tube is manufactured layer by layer around the damping stack by impregnation of fiber sheets by the matrix of the composite material.

[0031] The invention finally relates to an aircraft comprising a tubular frame. The frame comprises a set of tubes which comprises metal and composite tubes as defined above. brief description of the figures

[0032] The present invention will be better understood upon reading the description of exemplary embodiments, with reference to the appended drawings in which:is a schematic representation, partially in perspective and partially cut away, of a metal and composite tube according to a first embodiment;is a perspective representation of a damping stack and the second tube of the metal and composite tube according to the first embodiment;is a longitudinal sectional representation of a damping stack and the second tube of the metal and composite tube according to the first embodiment;illustrates the method of manufacturing the metal and composite tube according to the first embodiment;Figures 5a and 5b illustrate steps of the method of manufacturing a damping stack of the metal and composite tube according to the first embodiment;is a perspective representation of an aircraft chassis comprising a set of metal and composite tubes according to the first embodiment; FIG. 7 is a side view representation of an aircraft comprising a chassis formed by a set of metal and composite tubes according to the first embodiment;

[0033] For clarity, identical or similar elements are identified by identical reference signs in the drawings. DETAILED description of an embodiment

[0034] La represents a metal and composite tube 4, for example for a land and / or air vehicle 1 such as a light aircraft like the one shown in Figure 10. The metal and composite tube 4 comprises a first tube 6 made of metal material, a second tube 7 made of composite material, and at least one damping stack 8. More specifically, the metal and composite tube 4 comprises a plurality of damping stacks 8, 81, 83, 85. The metal and composite tube 4 is in particular a structural tube. In particular, the metal and composite tubes 4 serve to mechanically protect people inside a set of these metal and composite tubes 4, while limiting the mass and size of the set of metal and composite tubes 4.

[0035] In this document and in the absence of a specification to the contrary, an axial direction is a direction which is parallel to the longitudinal direction XX of the metal and composite tube 4. A radial direction is a direction which is locally perpendicular to the axial direction. An orthoradial direction is a direction which is locally perpendicular to the axial direction and to the radial direction. A transverse plane is a plane which is orthogonal to the longitudinal direction XX of the metal and composite tube 4. A transverse plane is formed by a radial direction and an orthoradial direction.

[0036] In the embodiment shown, the metal and composite tube 4 is cylindrical with a circular cross-section around the longitudinal direction XX of the metal and composite tube 4. The first tube 6 is cylindrical with a circular cross-section being centered around the longitudinal direction XX of the metal and composite tube 4. The second tube 7 is cylindrical with a circular cross-section being centered around the longitudinal direction XX of the metal and composite tube 4. Each damping stack 8 is cylindrical with a circular cross-section being centered around the longitudinal direction XX of the metal and composite tube 4.

[0037] The first tube 6 is made of a metallic material which comprises steel, aluminum and / or titanium. The first tube 6 envelops the second tube 7 made of composite material while being located outside the second tube 7. The first tube 6 delimits radially outwardly the metallic and composite tube 4.

[0038] When vehicle 1 is a motorized road vehicle, the metallic material includes, for example, steel. When vehicle 1 is an air vehicle, the metallic material is lighter and includes, for example, aluminum or titanium.

[0039] In each of the embodiments shown, the metallic material is a titanium alloy. The titanium alloy is, for example, a Grade 9 TiAL3V2.5 titanium alloy widely used in competition bicycle frames and aeronautical structures, which is manufactured by the company STAINLESS, or any other titanium alloy which offers a good compromise between the mechanical strength and the density of the metallic material.

[0040] The second tube 7 is made of composite material. The second tube 7 envelops the damping stack 8 while being located outside the damping stack 8. The second tube 7 is located radially between the damping stack 8 and the first tube 6. The second tube 7 is preferably of a shape substantially identical to that of the first tube 6, to facilitate mechanical contact between the second tube 7 and the first tube 6.

[0041] The second tube 7 is segmented along the longitudinal direction XX of the composite and mechanical tube. Each segment of the second tube 7 radially envelops one of the damping stacks 8, 81, 83, 85. In particular, each tube segment 7 has a length identical to the length of one of the damping stacks 8, 81, 83, 85 along the longitudinal direction XX of the composite and mechanical tube.

[0042] Each second tube segment 7 and each damping stack 8, 81, 83, 85 forms a damping assembly which is called “damping cartridge 9” in the embodiment shown, in particular due to its cylindrical shape. The damping cartridge 9 is delimited radially outwards by the second tube segment 7 which adheres to the damping stack 8. The damping cartridge 9 is delimited axially by transverse walls 84 of the damping stack 8.

[0043] The composite material of the second tube 7 and / or of each transverse wall 84 of each damping stack 8 comprises a matrix and reinforcing fibers. The matrix comprises at least one resin selected from at least one polyepoxide, one polyester and one polyetherketone. The reinforcing fibers comprise at least one element selected from carbon fibers, glass fibers and aramid fibers. Aramid fibers are also known under the trade name “kevlar”.

[0044] In the embodiment shown, the composite material comprises a polyepoxide and carbon fibers. The polyepoxide is, for example, the product known under the trade name “SR 1500” from the company Sicomin. The carbon fibers are, for example, fibers known under the name “C193 Sergé Carbone 193 g / m2 3K” from the company Sicomin. In the embodiment shown, the second tube 7 and each transverse wall 84 are made from the same composite material.

[0045] The damping stacks 8, 81, 83, 85 are contiguous along the longitudinal direction XX of the metal and composite tube 4. In other words, two consecutive damping stacks 81, 83 and 83, 85 along the longitudinal direction of the metal and composite tube 4 are in direct mechanical contact with each other. The damping stacks 8, 81, 83, 85 extend in particular over the entire axial length of the metal and composite tube 4. The number of damping stacks 8 inside the metal tube 4 depends for example on the axial length of the metal and composite tube 4.

[0046] Each damping stack 8 has an outer contour that is identical to the inner contour of the second tube 7. The damping stack 8 is located inside the second tube 7, being in radial contact with the second tube 7. Each damping stack 8 is formed by an alternating stack of damping foam and composite material. Each damping stack 8 comprises stages 80 of damping foam and transverse walls 84 between the stages 80 of damping foam. The damping stack 8 serves to effectively absorb energy in the event of impacts, while limiting the mass and size of the metal and composite tube 4.

[0047] The stages 80 of damping foam 80 are arranged in the longitudinal direction of the damping stack which is also the longitudinal direction XX of the metal and composite tube. Two consecutive stages 80 of damping foam are separated by a transverse wall 84. The transverse walls 84 play an important mechanical role in reducing the risk of buckling of the second tube 7 and therefore of the first tube 6 during an impact with lateral constraints. Each stage 80 of damping foam is formed by a block of damping foam. The stages 80 of damping foam successively absorb energy in the event of impacts of the metal and composite tube 4.

[0048] The number of stages 80 of each damping stack 8 is variable. Each transverse wall 84 is planar and extends transversely. Each transverse wall 84 is made of composite material. Each transverse wall 84 serves to separate two consecutive stages 80 of damping foam or to transversely delimit the damping stack 8. The transverse walls 84 limit the mechanical deformations of the stages 80 of damping foam that they axially delimit. The transverse walls 84 transmit the energy of an impact from one stage 80 of damping foam to the other in the axial direction.

[0049] In the embodiment shown, each damping stack 8 comprises four stages 80 of damping foam. The different stages 80 of damping foam are identical to each other. In particular, the damping foam of the different stages 80 of damping foam is identical and the thicknesses e of each stage 80 are equal in pairs. The transverse walls 84 are identical in pairs.

[0050] The cushioning foam of each cushioning foam stage 80 is a solid closed-cell foam. The cushioning foam is a cross-linked polymer foam suitable for a land and / or air vehicle. The density of the cushioning foam varies from one cushioning stack 8 to another. The cushioning foam of each cushioning foam stage 80 serves to absorb energy in the event of impacts against the metal and composite tube 4, by elastically deforming.

[0051] In the embodiment shown, the damping foam is for example a crosslinked polymer foam which is known under the trade name of "Airex", with densities of 60 kg / m3, 80 kg / m3 and 100 kg / m3. It is marketed by the company Sicomin. The foam can also be a metal foam made of an aluminum or titanium alloy such as the range of foams produced by the company GRIM NéoLATTICE. The foam can also be a LATTICE structure resulting from metal or plastic 3D printing.

[0052] In the illustrated embodiment of the metal and composite tube 4, the damping stacks 81, 83, 85 are different. The transverse walls 84 of each of the damping stacks 8 are identical. The stages 80 of the damping stacks 81, 83, 85 are different, with a density of damping foam which increases for the stages 80 of the damping stacks 81, 83, 85 towards a space for people such as a vehicle interior 1.

[0053] Illustrates the manufacturing method 100 of the metal and composite tube 4. The method 100 comprises a step 101 of manufacturing the first tube 6, a manufacturing step 200 of manufacturing the damping stack 8, a manufacturing step 300 of the second tube 7, and a step 106 of inserting the damping stack 8 and the second tube 7 inside the first tube 6. The order of the manufacturing steps 101, 200, 300 may vary. The step 106 of inserting the damping stack 8 and the second tube 7 inside the first tube 6 occurs after the manufacturing steps 101, 200, 300.

[0054] The first tube 6 is for example a commercial tube. The step 101 of manufacturing the first tube is generally a preliminary step which is implemented by people other than those who implement the other steps of the manufacturing method 100.

[0055] Figures 5a and 5b illustrate the step 200 of manufacturing each damping stack 8. Each damping stack 8 is formed by an alternating stack 201 of blocks 82 of damping foam and sheets 86 of fibers impregnated with composite material forming an initial stack 85. The initial stack 85 after polymerization and post-oven curing is then cut to the shape of the first tube 6 and the second tube 7. During the cutting step 203 of the initial stack 85, all of the blocks 82 of damping foam and sheets 86 of fibers impregnated with composite material are cut, preferably in one go. The initial stack 85 is for example heated and pressed, to promote the polymerization and drying of the composite material which will form the transverse walls 84, preferably before the cutting step 203. The initial stack 85 can also be placed under vacuum.

[0056] Figure 5b illustrates step 300 of manufacturing the second tube 7. The second tube 7 is manufactured layer by layer around the damping stack 8 by impregnation of fibers with the matrix of the composite material. The fibers of the composite material of the second tube 7 are for example in the form of sheets which are wound one after the other around the damping stack 8, after impregnation 203 of the fibers with the matrix. The composite material of the second tube 7 is for example put under mechanical pressure against the damping stack 8 before steaming and curing. The assembly of the second tube 7 and the damping stack 8 can be formed and laminated under vacuum before steaming and curing. Heating the composite material promotes in particular the polymerization and drying of the matrix of the composite material, in particular when the matrix is ​​a thermosetting resin such as a polyepoxide.

[0057] During step 106 of inserting the damping stack 8 and the second tube 7 inside the first tube 6, the damping stack 8 and the second tube 7 are for example inserted by force inside the first tube 6. The damping stack 8 and the second tube 7 are for example rigidly secured to the first tube 6, by being compressed inside the first tube 6.

[0058] Alternatively, during step 106 of inserting the damping stack 8 and the second tube 7 inside the first tube 6, the damping stack 8 and the second tube 7 are movable relative to the first tube 6, for example for sliding in the longitudinal direction XX of the metal and composite tube 4. The damping cartridge 9 formed by the damping stack 8 and the second tube 7 can thus be replaced easily, for example when the damping foam is damaged.

[0059] Figure 9 shows a chassis 2 for a land or air vehicle 1, which is a tubular chassis 2 and which comprises metal and composite tubes 4. The chassis 2 comprises vertices 20 and a set of tubes which comprises the metal and composite tubes 4. The chassis 2 serves to protect the people inside the aircraft in the event of an accident, passively, that is to say without control and without intervention by a pilot. The vertices 20 rigidly connect the metal and composite tubes 4 together. The metal and composite tubes 4 which are furthest from a passenger compartment of the vehicle 1 are configured to deform more quickly to absorb as much energy as possible sufficiently far from the people in the passenger compartment, in the event of an accident. The metal and composite tubes 4 which are closest to the passenger compartment are those which have the highest mechanical resistance, to protect the people inside the passenger compartment.

[0060] In particular, the metal and composite tubes 4 may include densities of shock-absorbing foam which vary according to the longitudinal direction XX of the metal and composite tubes 4, to best absorb shocks while protecting people in the vehicle.

[0061] Figure 10 shows a light aircraft 1 such as a tourist aircraft or an ultra light powered aircraft which is known as a ULM. The aircraft 1 comprises a frame 2, wings 3, wheels 5 and a propeller 6. The metal and composite tubes 4 of the frame 2 are particularly useful in the case of a light aircraft 1 in which the safety of the people on board is clearly likely to be improved.

[0062] Thanks to the metal and composite tube 4 according to the invention, the mechanical resistance of the tube 4 is very high, while limiting the mass and size of the tube 4. The safety of a pilot, a driver and / or passengers is improved, while limiting the mass and size of a vehicle 1 comprising the metal and composite tube 4. The manufacture of the metal and composite tube 4 is relatively easy. In particular, the damping stack 8 is relatively easy to manufacture.

[0063] The safety of people inside the vehicle 1 is improved, since the metal and composite tube 4 absorbs a large amount of energy during an accident of the vehicle 1, while deforming in a controlled manner, avoiding injury to people during the deformation of the tube 4. The metal material of the first tube 6, the composite material of the second tube 7 and the damping stack 8, and the damping foam, provide maximum energy absorption that is greater than the sum of the maximum energy absorbed by the metal material, by that absorbed by each composite material and by that absorbed by each damping foam, while controlling the deformation of the metal and composite tube 4.

[0064] The metallic material of the first tube 6 protects the damping foam and the composite material of the second tube 7 and / or the damping stack 8, in particular from radiation, mechanical shocks and humidity. By deforming more gradually, the metallic material contributes to controlling the deformation of the composite material and the damping foam by limiting the risk of sudden breakage of the composite material which would for example be likely to injure people in the vehicle 1. The risks of deterioration of the foam are limited, in particular by promoting elastic deformation of the foam.

[0065] The composite material has high resistance to deformation and impact, especially compared to the metallic material. The appearance of cracks in the composite material is accompanied by the plastic deformation of the metallic material. The number of dangerous fragments formed by deterioration of the composite material is very low. The composite material reduces the mass and bulk of the tubes compared to tubes of the same dimensions made only of metallic material.

[0066] The shock-absorbing foam is configured to deform elastically. It absorbs energy quickly and easily in the event of an accident. The shock-absorbing foam absorbs the energy of impacts of limited intensity. The maximum amplitude of deformation of the foam is reduced by each transverse wall and by the second tube, which limits damage to the foam, for example tearing of the foam. The foam effectively absorbs energy, while limiting the mass and size of the metal and composite tubes 4.

[0067] Each damping cartridge 9 can be replaced independently of the other damping cartridges 9 and independently of the first tube 6. The replacement of the damping cartridges 9 takes place, for example, due to the aging of the damping foam of the damping stacks 8.

[0068] Of course, various modifications can be made by those skilled in the art to the invention which has just been described without departing from the scope of the disclosure of the invention.

[0069] Alternatively, the second tube 7 envelops the first tube 6, being located outside the first tube 6. In this case, the damping stack 8 is inside the first tube 6.

[0070] Alternatively, the second tube 7 is axially single-piece.

[0071] Alternatively, the cross-section of the first tube 6, the second tube 7 and / or the damping stack 8 is polygonal. For example, the first tube 6, the second tube 7 and the damping stack 8 have a square cross-section.

[0072] Alternatively, the metal and composite tube 4 comprises a single damping stack 8 which has, for example, the same axial length as the axial length of the metal and composite tube 4.

[0073] Alternatively, at least two consecutive damping stacks 8 along the longitudinal direction XX of the metal and composite tube 4 are spaced and axially separated from each other. The metal and composite tube 4 then comprises at least one longitudinal section without damping stack 8.

[0074] Alternatively, the composite material of the second tube 7 is distinct from that of at least one transverse wall 84 of the damping stack 8. Alternatively, the thickness of each transverse wall 84 is variable depending on the desired mechanical characteristics and especially the position of the tube in the chassis 2.

[0075] Alternatively, the damping foam stages 80 of different damping stacks 8 are identical. Alternatively, two separate damping foam stages 80 of a damping stack 8 are different. The foam thickness may also vary between two stages 80.

[0076] Alternatively, the thickness of at least two separate stages 80 is different.

[0077] Alternatively, the cushioning foam and composite material are cut before being stacked.

[0078] Alternatively, the second tube 7 is manufactured layer by layer around a central insert by impregnating fibers with the matrix of the composite material. The fibers are, for example, in the form of sheets which are wound one after the other around a central insert, after impregnation of the fibers with the matrix. The central insert is inflated by a pressurized fluid, for example air, to press the composite material of the second tube 7 against the first tube 6. The composite material is, for example, heated when it is pressed by the central insert against the first tube 6. The insert is then depressurized and removed from the second tube 7, after the composite material of the second tube 7 has been fixed by adhesion to the first tube 6.

[0079] Alternatively, the metal and composite tube 4 is a structural tube for a use other than a land or air vehicle 1, for example for a tent peg.

[0080] Alternatively, the vehicle 1 is a motorized land vehicle 1, such as an automobile. Alternatively, the land vehicle 1 is a non-motorized vehicle such as a bicycle.

Claims

Metallic and composite tube (4), in particular for a land and / or air vehicle (1), comprising a first tube (6) made of metallic material, a second tube (7) made of composite material, characterized in that the metallic and composite tube (4) comprises a damping stack (8) inside the first tube (6) and the second tube (7), the damping stack (8) comprising at least a first stage (80) of damping foam and a second stage (80) of damping foam which are separated from each other by a transverse wall (84) made of composite material. A metal and composite tube (4) according to any one of the preceding claims, wherein the first tube (6) envelops the second tube (7) while being located outside the second tube (7), the second tube (7) enveloping the damping stack (8) while being located outside the damping stack (8). A metal and composite tube (4) according to any one of the preceding claims, wherein the metal and composite tube (4) is cylindrical with a circular cross-section, the first tube (6) is cylindrical with a circular cross-section, the second tube (7) is cylindrical with a circular cross-section, the damping stack (8) is cylindrical with a circular cross-section. A metal and composite tube (4) according to any preceding claim, wherein the damping foam of each damping foam stage (80) comprises a closed-cell solid foam, the damping foam preferably being a cross-linked polymer foam suitable for a land and / or air vehicle (1). A metal and composite tube (4) according to any one of the preceding claims, wherein the composite material of the second tube (7) and / or of the transverse wall (84) comprises a matrix and reinforcing fibers, the matrix comprising at least one resin chosen from at least one polyepoxide, one polyester and one polyetherketone, the reinforcing fibers comprising at least one element chosen from carbon fibers, glass fibers and aramid fibers. Metal and composite tube (4) according to the preceding claim, in which each transverse wall (84) is in the same composite material as the composite material of the second tube (7), and / or in which the composite material comprises a polyepoxide and carbon fibers. A metal and composite tube (4) according to any preceding claim, wherein the first tube (6) of metal material is made of a metal material which comprises aluminum and / or titanium, preferably a titanium alloy. Metal and composite tube (4) according to any one of the preceding claims, in which the damping stack (8) comprises at least three stages (80) of damping foam, two consecutive stages (80) of damping foam being separated by a transverse wall (84) made of composite material, and / or in which the stages (80) of damping foam of the damping stack (8) are two by two identical. A metal and composite tube (4) according to any one of the preceding claims, wherein the metal and composite tube (4) comprises at least two damping stacks (8, 81, 83, 85) inside the first tube (6) and the second tube (7), each damping stack (8, 81, 83, 85) comprising at least a first stage (80) of damping foam and a second stage (80) of damping foam which are separated from each other by a transverse wall (84) made of composite material. Metal and composite tube (4) according to the preceding claim, in which the metal and composite tube (4) comprises damping stacks (81, 83) adjoining in the longitudinal direction (XX) of the metal and composite tube, and / or in which a stage (80) of damping foam of one of the damping stacks (81) is different from a stage (80) of damping foam of another of the damping stacks (83, 85). Metallic and composite tube (4) according to any one of the preceding claims 9 and 10, in which the second tube (7) is segmented along the longitudinal direction (XX) of the composite and mechanical tube, each segment of the second tube (7) having a length identical to the length of one of the damping stacks (8, 81, 83, 85) along the longitudinal direction (XX) of the composite and mechanical tube. Method for manufacturing a metal and composite tube (4) according to any one of the preceding claims, comprising a step of manufacturing (200) the damping stack (8) by stacking at least two stages of damping foam separated by a transverse wall (84) made of composite material, a step of manufacturing (300) the second tube (7) around the damping stack (8), a step of inserting (106) the damping stack (8) and the second tube (7) inside the first tube (6). Method for manufacturing a metal and composite tube (4) according to the preceding claim, in which the damping stack (8) is manufactured by a stack of stages (80) of damping foam which are separated by transverse walls (84) made of composite material, and by cutting the damping foam and each transverse wall (84) to the shape of the first tube (6) and / or the second tube (7). Method for manufacturing a metal and composite tube (4) according to any one of the preceding claims 12 to 13, in which the second tube (7) is manufactured layer by layer around the damping stack by impregnation of fiber sheets with the matrix of the composite material. Aircraft (1) comprising a tubular chassis (2), the chassis (2) comprising a set of tubes which comprises metal and composite tubes (4) according to any one of claims 1 to 11.

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