DE20220600U1 - Aircraft used as rotary-wing aircraft, e.g. helicopter, comprises structural component at risk from impact/explosion which is made of lightweight composite material with rigid, strong support layer and fiber-reinforced elastomer layer - Google Patents

Abstract

Aircraft, especially a rotary-wing aircraft, especially a helicopter, comprises a structural component at risk from impact or explosion which is made of a plate- or shell-like lightweight composite material with at least one first rigid, strong support layer (2) produced from at least one metal material or a composite material, and at least one elastomer layer (4) fixed to the support layer. The elastomer layer is completely penetrated by reinforcing fibers (6) and forms a matrix for the reinforcing fibers. Preferred Features: The support layer comprises an aluminum material. The structural component is a base assembly or a base assembly component of the aircraft, a component of the power plant, a fuel tank arranged in a base element, or a fire-protection element.

Description

TECHNICAL TERRITORY

The invention relates to an aircraft, especially a rotary wing aircraft, and especially a helicopter.

STATE OF THE ART

Recent demands on aircraft structures relate in particular to passive safety, crash safety, Heat resistance, Thermal insulation, resistance against general shock and impact loads such as shelling and flying parts, high dynamic strength and damage tolerance, Tightness, corrosion resistance, Weight saving and ultimately one technically possible easy and economical processability. So it would be desirable, provide an aircraft structure or an aircraft can, which as many as possible fulfills these required properties as optimally as possible.

A special and extremely difficult Crash safety poses a problem in aircraft technology Water what what wing aircraft and rotary wing aircraft equally applies. A crash on water can be different than a crash No landing gear or landing gear on firm land - to reduce impact come into effect. Rather, the crash-related loads directly into the fuselage and or wing structure of the aircraft initiated. Consequently, there are extremely high requirements here the for the structure or the structural components of the aircraft used materials and materials. A similar Problems also arise in the event of a crash on mud or deep snow on. It would be therefore desirable that To be able to improve crash behavior.

Fiber-reinforced plastic materials and fiber-plastic-metal composite materials have opted for Aircraft applications basically proven. The processing of such However, materials is very demanding, and not just because of it the necessary equipment and the necessary manual work Skills but also due to the sometimes very different or contradicting ones Properties of the individual materials involved in the respective material composite. For the latter reason, the practical application of Composite materials in a component in terms of a desired practical Use of this component is a complex subject. A composite material which for a specific application or processing method Cheap is, can stand up for another application or processing method other than maximum highlight problematic.

This is in aircraft technology, in which composite materials mostly as highly multifunctional Materials are used, of particular importance, because the Composite materials can as a result of the problems described above, the sum of those for an application desired Usually do not or do not optimally fulfill properties or do not make optimal use of many material properties.

From the DE-OS 38 34 205 A composite material is known, comprising two rigid, tensile carrier layers, which are made of a metal material, namely steel, and an elastomer layer arranged between these carrier layers and firmly connected to the carrier layers. On the inner sides of the carrier layers facing the elastomer layer, these are each provided with a thin layer of a flexible metal mesh material which projects slightly, ie only close to the surface, into the elastomer layer. This metal mesh material forms a type of anchoring which is intended to improve the areal cohesion between the elastomer layer and the respective carrier layer.

A similar composite material, but without the aforementioned metal mesh layer, is shown in FIG U.S. Patent 6,050,208 disclosed.

Furthermore, so-called Fiber-plastic composite materials known which reinforcing fibers, such as glass, aramid or carbon fibers, boron fibers, ultra-strong Have polyethylene fibers etc., which are in a plastic matrix, such as a polyester or epoxy resin are embedded. Such materials are used in vehicle construction, especially aircraft construction quite common.

Furthermore, fiber-plastic-metal composite materials known as for aeronautical applications for example under the trade name Glare® or Arall® the Fokker Aerostructures B.V. to be expelled. With these materials it is plate-shaped Composite elements made of sheet metal and fiber-plastic composite panels, that are glued together. For example, Glare® is a composite from at least two aluminum sheets and a fiber-epoxy composite panel represents.

From the DE 100 62 859 A1 A plate-shaped composite material is known, comprising at least one first rigid, tensile carrier layer, which is made of a metal material, and at least one elastomer layer firmly connected to this carrier layer, which is essentially completely penetrated by reinforcing fibers and forms a matrix for the reinforcing fibers. This composite material is to be used for vibration damping applications. The DE 100 62 859 A1 provides a special binder for connecting the metal and elastomer layers.

Furthermore, from the DE 29 39 420 C2 known a composite material comprising at least one first stretch-resistant, tensile carrier layer, which is made of a composite material or metal material, and at least one elastomer layer firmly connected to this carrier layer, which is substantially completely penetrated by reinforcing fibers and forms a matrix for the reinforcing fibers. According to the DE 29 39 420 C2 are used for energy-absorbing elements in the manner of a spring or spring / damper element, ie, for example, as a leaf spring, damper, torsion bar and support beam or carrier for bridges.

PRESENTATION THE INVENTION

The object of the invention is the technical problem underlying an aircraft (in particular a rotary wing aircraft or a helicopter), which has improved crash safety and has improved impact behavior.

The aforementioned task is carried out according to a solved first aspect of the invention by an aircraft according to the invention with the features of claim 1.

This aircraft, in particular a rotary wing aircraft, in particular a helicopter, or else a missile or a spacecraft, includes an impact and / or impact and / or explosion endangered Structural component made of a plate or shell-shaped lightweight composite material with at least a first rigid, tensile carrier layer, which is made of at least one metal material, and at least one with this backing layer firmly bonded elastomer layer, which is essentially entirely of reinforcing fibers is interspersed and a matrix for the reinforcing fibers forms. A plate-shaped For the purposes of the invention, material also comprises a strip-shaped material.

The basis of the invention The task is also solved by an aircraft according to the invention with the features of claim 2.

This aircraft, in particular a rotary wing aircraft, in particular a helicopter, or else a missile or a spacecraft, includes an impact and / or impact and / or explosion endangered Structural component made of a lightweight composite material with at least a first rigid, tensile carrier layer made of a composite material, in particular a fiber composite material is produced, and at least one with this backing layer firmly bonded elastomer layer, which is essentially entirely made of reinforcing fibers is interspersed and a matrix for that reinforcing fibers forms.

Under "impact and / or impact and / or explosion-prone" components, structures and components are to be understood within the meaning of the invention, in a practical use of the aircraft a high load due to crash, accident, flying parts (e.g. in the event of engine failure), Bombardment, explosion impact etc. may be exposed. Such components and structures are, for example around skin elements of spacecraft, that are at risk from space debris (radoms, pylons, Antenna fairings, other external accessories, engine shrouds and other engine turkeys, especially of turbines, tanks, Cockpit fairings, explosion-proof aircraft containers, etc.

The (soft) penetrated by the reinforcing fibers The elastomer layer is also briefly referred to below as a fiber-elastomer composite layer be designated.

Stiff and tensile means in With regard to the backing layer, that this is significant compared to the fiber-elastomer composite layer greater stiffness and has tensile strength, which follows from the exemplary Description of the for the backing layer and the fiber-elastomer composite layer used materials and the arrangement of which will become even clearer. The reinforcing fibers can are in an isotropic, anisotropic or orthotropic arrangement, i.e. for example in the form of unidirectional or multidirectional fiber arrangements, Rovings, fiber mats or nonwovens with an agglomerate of individual fibers (Long or short fibers), laid fabrics, woven fabrics, knitted fabrics etc., or in mixed forms be provided from it. Such fiber structures can be both provide single and multi-layered. As reinforcing fibers preferably come fibers made of glass, carbon, aramid, metal, and also natural fibers (e.g. hemp, flax, jute), or a hybrid from these fibers for use.

“Completely made of reinforcing fibers enforced "means in the above Context and in the sense of the invention that the reinforcing fibers are not only on an outer edge area the elastomer layer, but also in other layer or thickness areas the elastomer layer or preferably in the thickness direction equally distributed are. The fiber content in the elastomer layer is approx. 20 up to 80%, preferably 30 to 70%, more preferably 35 to 60%, however, the invention is not limited to these ranges of values.

Aluminum, aluminum alloys, steel alloys, including corrosion-resistant steels, titanium and titanium alloys are preferably used for a carrier layer made of at least one metal material. The carrier layer can also be constructed from a plurality of metallic individual layers. A carrier layer made of a composite material can, for example, be a fiber-plastic composite material, both with a matrix made of a thermosetting and thermoplastic plastic, or a fiber-plastic-metal composite material (eg Glare ®), which can also contain a fine mesh made of a copper material, or a mixture of these.

For the elastomer layer, which is the matrix or elastomer matrix for the reinforcing fibers forms, can in principle any suitable elastomer material can be used, in particular also acrylonitrile butadiene rubber (NBR), acrylate rubber (ACM), Butyl rubber, chloroprene rubber (CR), ethylene propylene rubber (EPDM), fluororubber (FKM), rubber or rubber-like materials, such as natural rubber, also hydrogenated nitrile rubber (HNBR), neoprene, nitrile rubber (NBR), polyurethane elastomers (AU, EU), silicone rubber (VMQ), styrene-butadiene rubber (SBR), as well as thermally processable elastomers (TPE).

The aircraft according to the invention has of the above, for the impact and / or impact and / or explosive Structural component used lightweight composite material an improved Crash safety and improved impact behavior. The structural component has a low weight, which makes it suitable for lightweight applications or suitable for achieving weight savings, a high dynamic resilience, high residual strength after dynamic stress and generally a high damage tolerance with a low tendency to crack or lower crack propagation speed after damage. About that beyond it about good Damping properties, especially with high-frequency vibrations, as well as good shock absorption properties. Furthermore, the structural component made of said lightweight composite material has one good bending stiffness and very high elasticity at the same time less Elongation and shear stiffness of the fiber-elastomer composite layer. Because the material especially with a carrier layer made of metal as a whole is easily deformable or deformable, the structural component is also relatively easy to manufacture. But it does also about a high dielectric strength or resistance to general impact and impact loads like in a crash, by fire, an explosion or can occur due to flying parts. Because of a minor thermal conductivity in the thickness direction of for Structural component material used is high heat resistance and a high burn-through resistance can be achieved, and thereby again are good fire protection properties in the aircraft according to the invention reachable. Due to the material mentioned, the corresponding structural components can of the aircraft above it also good thermal insulation and liquid-tight be carried out and it is good corrosion resistance achievable. Because that for the structural component also used a lightweight composite material has good cold formability and is easy to process a technically relatively simple and economical production of high-quality components of the aircraft possible.

The aircraft according to the invention thus has a improved crash safety and passive safety, which in aircraft technology by is of particular interest.

More preferred and advantageous Design features of the aircraft according to the invention are the subject the dependent Expectations 3 to 11.

In the aircraft according to the invention can the shock and / or impact and / or explosion endangered Structural component can be produced from an intermediate product, which comprises: at least one prepreg layer and / or at least one unbound reinforcing fiber layer for the at least one first rigid, tensile composite support layer; and at least one with the prepreg layer or the unbound Reinforcing fiber layer bonded elastomer layer that is essentially entirely of reinforcing fibers is enforced.

Prepreg is generally already used factory-impregnated with special resin or impregnated Scrim and fabric. Under an unbound reinforcing fiber layer is a fiber layer, e.g. in the form of a fleece, a tissue or the like (see above) to understand that not yet with one Matrix material (e.g. resin) is provided. The unbound reinforcing fiber layer is therefore quite flexible. Both the prepreg layer and the unbound reinforcing fiber layer can besides the pure reinforcement fibers in principle other additional components such as a network structure made of thin copper wire or the like included. Furthermore, the prepreg layer or the unbound reinforcing fiber layer is form-fitting and / or by means of a suitable adhesive, adhesive (including adhesive films), or the like with the fiber-elastomer composite layer. These connections can be both area, entire area as well locally or executed selectively his. moreover can in the intermediate according to the invention the prepreg layer or the unbound reinforcing fiber layer and the Fiber-elastomer composite layer initially a relatively loose composite form, which however represents a unit, and only in a later processing step be firmly connected.

The intermediate is simple and effective way to said structural component of the aircraft according to the invention to process or edit and allows the structural component to produce in a rational and economical manner, including three-dimensional shapes and components can be realized.

The in the aircraft according to the invention for the shock and / or impact and / or ex The lightweight composite material used for the structural component that is at risk of explosion can be produced by means of a method from the intermediate product described above, which is provided with at least one unbound reinforcing fiber layer for the at least one first rigid, tensile composite carrier layer, the method comprising the following steps, but not necessarily in in the given order: deformation of the unbound reinforcing fiber layer by the action of force; and as a result elastic deformation of the at least one elastomer layer which is substantially completely penetrated by reinforcing fibers, the reinforcing fibers embedded in the elastomer matrix adopting a changed fiber course which essentially follows the elastic deformation due to the elastic deformation; Applying a resinous plastic material to the unbound reinforcing fiber layer (this can be done manually or by machine, for example in an injection or nozzle application process); Curing the applied resin-like plastic material, whereby a stretch-resistant, tensile carrier layer is formed from a hardened, solid fiber-plastic composite; and maintaining the elastic deformation of the elastomer layer and the changed fiber course of its reinforcing fibers by means of the hardened, solid fiber-plastic composite.

In addition, the aircraft according to the invention for the impact and / or impact and / or explosive Structural component used lightweight composite material by means of Above intermediate, which with at least one prepreg layer for the at least a first rigid, tensile composite carrier layer is provided, can be produced by a method, the following Steps include, but not necessarily in the given Sequence: deformation of the prepreg layer, preferably under the influence of heat, by force; and thereby elastic deformation of the at least one, essentially complete of reinforcing fibers interspersed elastomer layer; being the one in the elastomer matrix embedded reinforcement fibers through the elasticity of the elastomer matrix essentially one of the elastic deformation following, changed Accept fiber orientation; Harden the at least one prepreg layer under the action of heat; and maintain the elastic deformation of the elastomer layer and the modified Fiber course of the reinforcing fibers by means of the deformed and hardened prepreg layer. In particular when cold shaping the prepreg layer, make sure that the Degree of deformation selected in this way is that the reinforcing fibers do not detach the prepreg layer from its matrix material. in the In case of deformation under the influence of heat in contrast, the matrix material of the prepreg becomes plastic, so that here larger deformations carried out can be. Naturally it should also be noted that the reinforcing fibers of the elastomer layer do not detach from the elastomer matrix.

The deformation can be caused by the weight of the Intermediate product (e.g. by inserting the intermediate product in a simple form of lamination) or by deliberately exercising an outer, flat or linear Force on a predetermined area of the intermediate product (e.g. by vacuum pressing or pressing with Stamp and die). Deformation can be done with the help be carried out by at least one auxiliary tool which has the desired surface shape one from the intermediate or the resulting composite material reproduces the component to be produced. Furthermore, tools can be used to achieve this an improved surface quality of the lightweight composite material be used.

With the previously described procedures can be obtained from the intermediate in a simple and effective manner three-dimensionally shaped, and / or components of the aircraft according to the invention that are subject to impact and / or explosion produce. The elastic deformation state of the fiber-elastomer composite layer is here through the finished composite backing (i.e. the hardened Prepreg layer or in the hardened plastic material matrix embedded reinforcing fiber layer) "frozen" and stabilized. This can be done through natural Relaxation of the elastically deformed elastomer material are supported. If the pure deformation steps are omitted, then simple Way flat, plate or strip-shaped lightweight composite materials according to the invention manufacture.

That in the aircraft according to the invention for the shock and / or impact and / or hazardous Structural component used lightweight composite material, which with a rigid, tensile carrier layer is provided, which consists of at least one metal material, a thermoplastic or made of a thermoplastic fiber composite material can also be edited according to a procedure, the following Steps include, but not necessarily in the given Sequence: plastic deformation of the at least one carrier layer and thereby elastically deforming the at least one, substantially completely of reinforcing fibers penetrated elastomer layer, the embedded in the elastomer matrix reinforcing fibers through the elasticity of the elastomer matrix essentially one of the elastic deformation following, changed Accept fiber orientation; and maintaining the elastic deformation the elastomer layer and the modified Fiber course of the reinforcing fibers by means of the plastically deformed carrier layer.

When deforming the backing is on it Ensure that the degree of deformation is selected so that the resulting deformation of the fiber-elastomer composite layer does not detach its reinforcing fibers from the elastomer matrix.

The plastic deformation of the carrier layer and thus the entire lightweight composite material according to the invention through a suitable forming step, such as printing forms, Train pressure forming, train forming, bending forming, shear forming, in particular also forming with a stamp and die or a molding process, stretch drawing, Deep drawing including Vacuum forming (positive and negative processes), beads, etc., realized become. With a carrier layer made of a thermoplastic or a thermoplastic fiber composite material is the plastic deformation of the carrier layer and thus the entire Lightweight composite material expediently under suitable the effect of heat carried out.

In contrast, the carrier layer is made of a metal material manufactured, the carrier layer is plastically deformed and thus the deformation of the entire lightweight composite material preferably cold (cold forming). But there is also a heat optional here. Cold forming is with most metal materials easy to implement, but only with titanium restrictions are to be made; However, titanium can be deformed very well, which, however, requires a considerable amount of heat and with regard to the processing of the lightweight composite material therefore at most for very thin Titanium layers is conceivable. With hot forming in any case make sure that the elastomer material of the fiber-elastomer composite layer not thermally damaged becomes.

With the procedure described above so is it possible that in the aircraft according to the invention for the shock and / or structural component that is subject to impact and / or explosion Lightweight composite material in its entirety similar to a conventional one Form metal material or thermoplastic material, in particular but also to be cold formed. Such techniques were used in fiber composites so far not feasible. The method can be used for the aircraft according to the invention high-quality three-dimensional components and structures particularly simple, manufacture effectively and economically.

It is particularly advantageous if, in the aircraft according to the invention, in particular in the case of a rotary wing aircraft or helicopter, the structural component which is subject to impact and / or impact and / or explosion 7 is a floor assembly or floor assembly component. In view of the problems described at the outset and the advantages of the lightweight composite material used, the crash behavior of the aircraft can be considerably improved in this way.

As an example it should be mentioned that in the case of a helicopter, the tank usually arranged in the base assembly of the helicopter cell and ergo in the event of a hard emergency landing or a crash, in particular on water, particularly at risk is. Here the bursting of the tank must be prevented as far as possible become. equally However, water should also penetrate the cell or soil structure of the helicopter prevented become. Here are the positive properties of the used Lightweight composite material fully bearable, and the crash behavior and the safety of the helicopter can be improved significantly.

moreover it turned out to be cheap proved that the shock and / or impact and / or hazardous Structural component of the aircraft according to the invention a fire protection element is. The advantages also result from the already discussed in detail at the beginning positive properties of the lightweight composite material used.

A preferred embodiment the invention with further design details is below with reference to the accompanying drawings described in more detail and explained.

SHORT DESCRIPTION THE DRAWINGS

It shows:

1 is a schematic, greatly simplified and partially sectioned front view of an aircraft according to the invention in the form of a helicopter, which is equipped with shock and / or impact and / or explosion-prone structural components which are made of lightweight composite material;

2 is a schematic cross-sectional view of one for the impact and / or impact and / or explosion-prone structural components of the helicopter of 1 used lightweight composite material according to a first embodiment;

3 a schematic cross-sectional view of a lightweight composite material according to a second embodiment;

4 a schematic cross-sectional view of a lightweight composite material according to a third embodiment; and

5 is a schematic cross-sectional view of an intermediate product for producing the lightweight composite material used in the helicopter according to the invention.

PRESENTATION A PREFERRED EMBODIMENT

In the following description and in the figures, identical parts and components are also identified with the same reference numerals to avoid repetition, provided that none ne further differentiation is required.

1 shows a schematic, greatly simplified and partially sectioned front view of an aircraft according to the invention in the form of a helicopter 12 with structural components that are impact and / or impact and / or explosive 16 . 18 is equipped, which are made of lightweight composite material. The cell 14 of the helicopter 12 is in their floor area where there is a fuel tank 16 is, to a large extent made of a lightweight composite material, as will be described in more detail below. In the present case, the floor area comprises a double-walled floor element 18 which comprises said lightweight composite material.

The 2 shows a schematic cross-sectional view of the structural components that are impact and / or impact and / or explosive 16 . 18 of the helicopter 12 of 1 used lightweight composite material according to a first embodiment. In its basic version, this plate-shaped or strip-shaped lightweight composite material comprises a first stretch-resistant, tensile carrier layer 2 made of a metal material (here: an aluminum alloy) and one with this carrier layer 2 firmly connected elastomer layer 4 that are essentially entirely of reinforcing fibers 6 is interspersed and a matrix for the reinforcing fibers 6 forms. As an alternative to the metal material described above, the carrier layer 2 but also be made from a composite material, such as an epoxy-aramid fiber composite, a fiber-plastic-metal composite, or the like.

The reinforcement fibers 6 interspersed elastomer layer 4 is also briefly referred to below as a fiber-elastomer composite layer 8th be designated. As an elastomer material for the fiber-elastomer composite layer 8th In the present example, acrylonitrile butadiene rubber (NBR) is used as reinforcing fibers 6 Glass fibers are used here, which, as indicated in the drawing, refer to the thickness and the longitudinal and transverse extension of the elastomer layer 4 essentially even in the elastomer layer 4 are distributed.

The backing layer 2 has a thickness of approx. 0.3 mm and the fiber-elastomer composite layer 8th a thickness of 0.7 mm. The fiber content in the fiber-elastomer composite layer 8th is approximately 55%. Basically, the fiber content in the fiber-elastomer composite layer 8th depending on the embodiment and production method in a range of about 20 to 80%, preferably 30 to 70%, more preferably 35 to 60%, the invention being not restricted to these value ranges.

In the 3 is a schematic cross-sectional view of one for the shock and / or impact and / or explosive structural components of the helicopter of FIG 1 used lightweight composite material according to a second embodiment. This lightweight composite material has compared to the in 1 shown basic form a further, ie second rigid, tensile carrier layer 2 (also made of an aluminum alloy), and the fiber-elastomer composite layer 8th is between the first and second carrier layers 2 . 2 arranged and firmly connected to these layers. This results in a sandwich-like structure of the lightweight composite material. Although with this variant both carrier layers 2 . 2 are made of an aluminum alloy, it should be noted that the respective carrier layers 2 . 2 can in principle also be made of different materials, for example a carrier layer made of aluminum and the other made of another metal material or an epoxy-glass fiber composite or the like. The thickness of the support layers 2 . 2 in this embodiment is approximately 0.25 mm and the thickness of the fiber-elastomer composite layer 8th about 1.5 mm.

4 shows a schematic cross-sectional view of a for the shock and / or impact and / or explosion-prone structural components of the helicopter of FIG 1 used lightweight composite material according to a third embodiment, which has a plurality of alternating carrier layers 2 and fiber-elastomer composite layers 8th has (the reinforcing fibers of the fiber-elastomer composite layers 8th are in the drawing 4 not shown separately for the sake of clarity). With a variant of this type, increased burn-through resistance and dielectric strength can be achieved, for example, with a small material thickness. The backing layers 2 have a uniform thickness of approx. 0.2 mm and the fiber-elastomer composite layers 8th uniformly a thickness of approx. 0.4 mm. The thicknesses of the respective carrier layers 2 and fiber-elastomer composite layers 8th can also differ from one another within the lightweight composite material.

The previously discussed lightweight composite materials are for example in the form of plate or strip-shaped semi-finished products for the Manufacturing of the relevant structural components provided. Under a plate or strip shape are not just flat structures, but also curved ones, for example or to understand corrugated sheet-like shapes. In addition, the used lightweight composite materials basically also in the form of semi-finished products with open or closed cross-sectional shapes or in shape a component made of the lightweight composite material disposal stand.

In the 5 is a schematic cross-sectional view of an intermediate product is shown, which is used to manufacture the structure in the helicopter according to the invention for the shock and / or impact and / or explosion-prone structure Components used lightweight composite material can be used. This intermediate product comprises two unbound reinforcement fiber layers 10 For two rigid, tensile composite carrier layers of the lightweight composite material to be produced from the intermediate product, as well as one with the unbound reinforcing fiber layers 10 connected elastomer layer 4 that are essentially entirely of reinforcing fibers 6 is interspersed (fiber-elastomer composite layer 8th ). Instead of the unbound reinforcing fiber layers 10 In a further embodiment (not shown) of the intermediate product, prepreg layers can also be provided.

A first example of a method for producing a three-dimensionally shaped lightweight composite material from an intermediate product will now be described 5 to be discribed. This method is preferably suitable for manual production.

A web of the intermediate product, which is cut to a desired dimension, is placed in a concave fabric, the intermediate product largely adapting to the inner contour of the mold due to its own weight. In this process, the outer, unbound reinforcing fiber layers 10 (please refer 5 ) deformed by external force (here: by the pure weight of the intermediate product itself). At the same time, the fiber-elastomer composite layer 8th elastically deformed. The reinforcing fibers follow 6 the fiber-elastomer composite layer 8th due to the elasticity of the elastomer matrix, its elastic deformation and assume a changed fiber course, that is to say the contour of the laid shape. Then the first unbound reinforcing fiber layer is placed on top of the lay-up 10 an epoxy resin is applied and the first unbound reinforcing fiber layer 10 soaked with it.

Because of the fiber-elastomer composite layer 8th the epoxy resin cannot enter the second unbound reinforcing fiber layer in the lay-up 10 penetrate. By placing a film on the impregnated first unbound reinforcing fiber layer 10 and evacuating the laid mold, the intermediate product is pressed firmly against the contour of the mold. Then the applied epoxy resin is allowed to harden. The resulting molded part is already largely stable and is removed from the fabric. Then the second unbound reinforcing fiber layer 10 in an analogous manner with epoxy resin and the epoxy resin cured.

With the help of the unbound reinforcing fiber layers 10 . 10 applied and cured epoxy resin form two rigid, tensile carrier layers made of a cured, solid fiber-epoxy composite.

The elastic deformation of the elastomer layer or fiber-elastomer composite layer achieved in the process described above 8th and the changed fiber course of their reinforcing fibers 6 is maintained by means of the hardened, solid fiber-plastic composite of the carrier layers. The result is a three-dimensionally shaped component made of the said lightweight composite material.

In a second example of a method for producing a three-dimensionally shaped lightweight composite material from an intermediate after 5 For example, the intermediate product can be machined on both sides by means of suitable application devices (ie on the unbound reinforcing fiber layers 10 . 10 ) be provided with resin. Provided that the intermediate product is not deformed further, but is brought into a flat state, it is possible in this way to produce plate or strip-shaped lightweight composite materials. In the present case, however, the prepared and resin-coated intermediate product is wound on a mandrel with a round cross section. Here, the unbound, but already provided with resin reinforcing fiber layers 10 deformed, the effects already explained in the previous example with regard to the fiber-elastomer composite layer and its reinforcing fibers occur. After the resin has hardened, a shell-shaped or tubular component is produced from said lightweight composite material.

In a third example of a method for Manufacture of a three-dimensionally shaped lightweight composite material an intermediate product is used in which instead of unbound Layers of reinforcing fibers prepared prepreg layers are available. Because the prepreg layers are already provided with a resin, can be applied separately of resin are eliminated. The steps of deforming the prepreg layers and the fiber-elastomer composite layer can for example be analog to which the two method variants described above are carried out. The curing the prepreg layers take place under the influence of heat, for example in the autoclave. The effects that occur or are achieved the same as in the previous embodiments. When making more complex three-dimensional component shapes, it is also recommended to deform the prepreg layers under the influence of heat make, because the prepreg layers at a suitable temperature then plastic or show some plastic properties.

There is now a method for processing a structural component of the helicopter of a shock and / or impact and / or explosion hazard 1 usable lightweight composite material are described, as in 3 is shown. As already mentioned, this material has two outer carrier layers 2 . 2 made of an aluminum alloy with the fiber elasto merverbundschicht 8th are glued. It is assumed that the lightweight composite material is provided in the form of a flat, plate-shaped semi-finished product. For processing, this semi-finished product is deformed by means of a stamp and a die, which are part of a pressing device, not shown. More precisely, the action of the stamp and the matrix make the two carrier layers 2 . 2 plastically deformed. This deforms the between the two carrier layers 2 . 2 arranged fiber-elastomer composite layer 8th elastic, ie it follows the deformation of the carrier layers 2 . 2 , which again in the elastomer matrix (elastomer layer 4 ) embedded reinforcement fibers 6 through the elasticity of the elastomer matrix assume a changed fiber course that essentially follows the elastic deformation. The elastic deformation of the elastomer layer caused 4 and the changed fiber course of their reinforcing fibers 6 are made by means of the plastically deformed carrier layers 2 . 2 and maintain any relaxation of the deformed elastomer matrix.

The procedure explained above is basically also suitable for processing lightweight composite materials that have a or several carrier layers made of a thermoplastic or a thermoplastic fiber composite material feature. in this connection the plastic deformation of the carrier layer then takes place under Heat, which ensures easier deformability of the carrier layer.

If a lightweight composite material is used in the methods explained in the context of the present description, in which the material with reinforcing fibers 6 interspersed elastomer layer 4 has a thermoplastic elastomer material, then the fiber-elastomer composite layer is preferably plastically deformed under the action of heat and then cooled. Cooling can be carried out actively with the aid of suitable coolants or passively by cooling the elastomer material itself. The deformation of the elastomer layer and the changed fiber course of its reinforcing fibers are then maintained not only by the carrier layers but also by the plastically deformed and again cooled thermoplastic elastomer material itself.

The lightweight composite material described can preferably also for a fire protection element and / or another impact and / or impact and / or explosion endangered Structural component of the aircraft according to the invention used e.g. For a component of an engine of the aircraft. As before mentioned, However, it is particularly suitable for a floor assembly or Floor assembly component of the aircraft according to the invention.

With the lightweight composite material, that within the scope of the aircraft according to the invention for the shock and / or structural component which is subject to impact and / or explosion will, both the backing layer as well as the fiber-elastomer composite layer contain other additives that affect the properties of the material additionally influence. At the joint between a carrier layer and the fiber-elastomer composite layer or an adjoining one Area can means to improve the flat Cohesion between the carrier layer and the fiber-elastomer composite layer be provided (e.g. in the form of adhesives, adhesives, Anchorages, etc.).

Furthermore, said Lightweight composite material in addition to the examples given above Thickness information for the carrier layer one Thickness in a range from 0.1 mm to greater than 1.5 mm, in particular 0.2 mm to greater than 1 mm, and for the fiber-elastomer composite layer has a thickness of 0.2 mm to greater than 10 mm, in particular 0.8 mm to 6 mm, preferred. The total thickness of the lightweight composite can therefore, depending on the application and embodiment, between a fraction one millimeter to a few centimeters, whereby from weight reasons an overall thickness in the millimeter range is preferred.

Reference signs in the claims, the The description and the drawings serve only for a better understanding of the Invention and are not intended to limit the scope.

Designate it:

2

Trägerschichten)

4

Elastomerschicht

6

Verstärkungsfasern in 4

8

Faser-Elastomerverbundschicht(en) aus 4 und 6

10

Ungebundene Verstärkungsfaserschicht(en)

12

Hubschrauber

14

Zelle

16

Treibstofftank

18

Bodenelement

LIST OF REFERENCE NUMBERS

2

Backings)

4

elastomer layer

6

Reinforcing fibers in 4

8th

Fiber-elastomer composite layer (s) from 4 and 6

10

Unbonded reinforcing fiber layer (s)

12

helicopter

14

cell

16

fuel tank

18

floor element

Claims (11)

Aircraft, in particular a rotary wing aircraft, in particular a helicopter ( 12 ), comprising a structural component that is impact and / or impact and / or explosive ( 16 . 18 ) made of a plate or shell-shaped lightweight composite material with at least one first rigid, tensile carrier layer ( 2 ), which is made of at least one metal material, and at least one with this carrier layer ( 2 ) firmly bonded elastomer layer ( 4 ), which is essentially entirely made of reinforcing fibers ( 6 ) is enforced and one Reinforcing fiber matrix ( 6 ) forms. Aircraft, in particular a rotary wing aircraft, in particular a helicopter ( 12 ), comprising a structural component that is impact and / or impact and / or explosive ( 16 . 18 ) made of a plate or shell-shaped lightweight composite material with at least one first rigid, tensile carrier layer ( 2 ), which is made of a composite material, and at least one with this carrier layer ( 2 ) firmly bonded elastomer layer ( 4 ), which is essentially entirely made of reinforcing fibers ( 6 ) is interspersed and a matrix for the reinforcing fibers ( 6 ) forms. Aircraft according to claim 1 or 2, characterized in that the lightweight composite material further comprises at least one second rigid, tensile carrier layer ( 2 ), and the at least one, essentially completely of reinforcing fibers ( 6 ) penetrated elastomer layer ( 4 ) between the two carrier layers ( 2 . 2 ) arranged and firmly connected to them. Aircraft according to one or more of the preceding claims, characterized in that the lightweight composite material comprises a plurality of alternating, rigid, tensile carrier layers ( 2 ) and essentially entirely of reinforcing fibers ( 6 ) interspersed with elastomer layers ( 4 ) having. Aircraft according to one or more of the preceding claims, characterized in that the reinforcing fibers ( 6 ) which the elastomer layer ( 4 ) essentially fully enforce, based on the thickness and length and length of the elastomer layer ( 4 ) essentially uniform in the elastomer layer ( 4 ) are distributed. Aircraft according to one or more of the preceding claims, characterized in that the at least one first, rigid, tensile support layer (made of at least one metal material) ( 2 ) comprises an aluminum material. Aircraft according to one or more of the preceding claims, characterized in that the rigid, tensile carrier layer ( 2 ) has a thickness of 0.1 mm to greater than 1.5 mm, in particular 0.2 mm to greater than 1 mm, and that of reinforcing fibers ( 6 ) penetrated elastomer layer ( 4 ) has a thickness of 0.2 mm to greater than 10 mm, in particular 0.8 mm to 6 mm. Aircraft according to one or more of the preceding claims, characterized in that the impact component and / or impact and / or explosion-prone structural component is a floor assembly or floor assembly component ( 18 ) of the aircraft. Aircraft according to one or more of the preceding claims, characterized characterized that the shock and / or structural component that is prone to impact and / or explosion Component of an engine of the aircraft. Aircraft according to one or more of the preceding claims, characterized in that the structural component, which is impact and / or impact and / or explosive, has a structural element in a floor element ( 18 ) arranged fuel tank ( 16 ) of the aircraft. Aircraft according to one or more of the preceding claims, characterized characterized that the shock and / or structural component that is prone to impact and / or explosion Fire protection element is.