Method for manufacturing a three-dimensional, multi-layered fiber composite component and a component manufactured using the methods

Abstract

Method for producing a three-dimensional, multilayer fiber composite component (11), the method comprising the steps: I. Layer-by-layer application of a curable matrix material (8) onto a substrate (12) in superimposed matrix layers by at least one application unit (6) movable relative to the substrate (12), wherein matrix material (8) applied in one layer forms a matrix layer; II. At least partial, strand-by-strand application of at least one fiber element (19) onto at least one of the matrix layers by at least one placement head movable relative to the substrate (12); III.Curing of the matrix material (8), wherein the matrix material (8) is a thermoset and short fibers (20) are embedded in the thermosets, wherein the short fibers (20) have a shorter length than the applied fiber element (19), characterized in that the matrix material (8) is alternately a fiber-containing matrix or a thermoset foam in layers.

Description

The invention relates to a method for producing a three-dimensional, multilayer fiber composite component according to claim 1 and to a component according to claim 19.It is known from the prior art to produce products by means of additive manufacturing. In prototype construction in particular, plastic parts with small numbers are required, which are produced by production methods such as "rapid prototyping".EP 2 739 460 B1 on which the preamble of claim 1 is based discloses a method which, with the generative application of a thermoplastic material, simultaneously feeds a continuous fiber and embeds it in the thermoplastic.In additive manufacturing, individual layers of matrix material are applied to an object carrier and a curing process often takes place after each layer application, for example by heating, in order to solidify the layer. A further layer can now be applied to this layer, which is in turn cured, so that when these steps are repeated, a component is built up layer by layer.The production of fiber bundle components is carried out either with at least one one one-sided mold half or with a core, onto which the material is / is deposited in layers manually or mechanically. There is therefore no production of fiber-reinforced fiber composite components having approximately significant mechanical properties, such as static and / or dynamic strengths or elasticities. For these reasons, additive manufacturing is currently used for the production of industrial articles of application only for metallic products or in areas in which no high requirements are placed on the material properties with regard to strength and stability.Such a method for producing fiber composite components is also known from the patent specifications WO 2014 / 193505 A1, US 2014 / 0291886 A1 and US 6214279 B1. DE 101 32 749 A1 also describes a fiber-reinforced material based on thermosetting polymers.The object of the invention is a method for producing a rigid and elastic and thus mechanically loadable fiber composite component, which satisfies the industrial requirement for material properties with respect to strength, stability and complexity, and also takes account of industrial demands on economic efficiency and a short production time.The object is achieved by a method having the features of claim 1.The proposed method is suitable for producing a three-dimensional multilayer fiber composite component. In the method, a curable matrix material is applied layer by layer to an object carrier in matrix layers arranged one above the other. The object carrier can be, for example, a plate which is not part of the component and on which a fiber composite component is built up layer by layer. In a further embodiment, the object carrier can be a component core which is part of the fiber composite component and onto which the matrix layers can be applied.A matrix layer is thus distinguished in that it is applied layer by layer following a contour of the object carrier. After each layer application, a curing process, for example by heating, can be carried out, which cures the matrix layer, so that the matrix material remains in its applied layer form. Thus, a further layer can be applied to the cured layer. Preferably, a layer is first completely applied and cured before starting with a new layer. The matrix material is applied by at least one application unit movable relative to the object carrier. The application unit can comprise a multiaxial geometry with at least 3, preferably 6 axes.In a further step, at least one fiber element is applied at least in regions onto at least one of the matrix layers by means of at least one laying head which can be moved relative to the object carrier in a strand-wise manner. A fiber element can be, for example, a so-called continuous fiber, i.e. a fiber strand which is wound, for example, on a spool and has a length of several meters. This "continuous fiber" can be applied by the laying head to a matrix layer in a selectable length and is severed in a selected length. When the continuous fiber is used up, additional continuous fiber can be wound onto the spool, so that the length of the wound fiber element appears "endless". The laying head can comprise a multiaxial geometry which comprises at least 3, preferably 6 axes. The multiaxial geometry can preferably be the same multiaxial geometry on which the application unit is likewise arranged.The matrix material is a thermosetting plastic. Thermosetting plastics are hard and brittle materials which have a high strength and temperature resistance. In addition, short fibers are embedded in the thermosetting matrix material in order to increase the elasticity and the strength of the fiber composite part. The short fibers can preferably be glass or carbon fibers with higher elastic moduli than the elastic modulus of the matrix material. The embedding of short fibers in the thermosetting matrix material has the aim of utilizing the respective positive mechanical properties of the matrix material and of the short fibers, such that the composite of matrix material and short fibers has a higher elasticity and strength than that of the matrix material and a higher strength than that of the short fibers. The short fibers preferably have a shorter length than the applied fiber element. This makes it possible to achieve improved mixing of the short fibers with the matrix material. The modulus of elasticity of the matrix material with embedded short fiber depends on the matrix and short fiber material as well as on the proportion of the short fibers and is typically between 2 and 14 GPa. However, highly stressed components can be exposed to higher loads in some areas. In order to solve this problem, the fiber element is additionally applied in regions. The fiber element can preferably be applied to the component in such a way that it is subjected to tensile stress along its longitudinal axis. The tensile modulus of elasticity of the fiber element along its longitudinal axis is preferably at least 70 GPa. This is significantly higher compared to the tensile modulus of elasticity of typical thermoplastics (1 to 3 GPa) and thermosetting plastics (about 1 GPa) and can thus promote the elasticity of the fiber composite component.The combination of thermosetting matrix material with embedded short fibers and additionally at least one fiber element applied in regions can make it possible to use fiber composite components as medium- to high-strength functional components on account of improved structural properties of the overall structure.The selected material combination thus solves the problem that mechanically medium-to-high-load fiber composite components having a strength of at least 10 GPa and elastic moduli of between 12 and 15 GPa can be produced according to the present state of the art with difficulty or not at all by means of additive manufacturing methods. This is because commonly used plastics have either high strength and low elasticity or high elasticity and low strength. As a result, additive manufacturing methods according to the current state of the art use thermoplastic matrix materials which have a high elasticity with low strength, but, in contrast to brittle plastics, are easier to process and it seems easier to increase the strength by additional application of fibre elements than to achieve an increased elasticity in brittle components. Unlike thermosets, which have once been heated above the cross-linking temperature (but below the decomposition temperature), thermoplastics change shape and liquify with heating just like brittle plastics. In the case of thermoplastics, this process is substantially reversible. This applies to a relatively long exposure to a low temperature and also to a brief, strong heating.Complex component shapes, in particular hollow components, can be built up layer by layer by means of additive methods without component cores, which are produced cost-intensive with shapes in conventional methods. Even in comparison with the use of laid scrims, less waste is produced with the method according to the invention, so that material is saved. The targeted, material-saving component reinforcement additionally has an advantageous effect on a weight reduction of the fiber composite component.In one possible embodiment, the matrix material can be thixotropic. An additional step can be carried out in the method. For example, by stirring, the viscosity of the matrix material can be reduced before application, i.e. the matrix material becomes more viscous. Thus, the application can be facilitated. If the matrix material is not subjected to any further shearing stress after application, it solidifies again up to its initial viscosity, i.e. the state which it is subjected to before the action of shearing forces, for example. Stirring had occurred. Already before the method step of curing, the matrix material can thus contribute additionally or alternatively to the later curing to the shaping of the fiber composite component. The difference between the initial viscosity and the minimum viscosity is typically in a range between 50 mPA s and 10000 mPA s.According to the invention, the matrix material is alternately a fiber-containing matrix or a thermoset foam layer by layer. It is advantageous in this embodiment that components and / or component cores can be manufactured which have a low density and high strength. Particularly preferably, polyurethane foams can serve as matrix material. However, other foamable thermosetting plastics such as epoxy, for example, can also be used as matrix material. The density can be, for example, at least 50 kg / m 3, preferably at least 75 kg / m 3, in particular preferably 80 kg / m 3. Furthermore, the density can be, for example, not more than 800 kg / m 3, preferably not more than 700 kg / m 3, particularly preferably not more than 600 kg / m 3. A compressive strength can be, for example, at least 50 N / mm 2, preferably at least 70 N / mm 2, particularly preferably at least 80 N / mm 2. The compressive strength can be, for example, at most 600 N / mm 2, preferably at most 700 N / mm 2 or particularly preferably at most 800 N / mm 2. The compressive strength can be determined, for example, by at least one test described in one of the following standards: ISO 844, DIN EN ISO 3386, DIN EN ISO 604, DIN EN 2850, DIN V 65380, DIN 65375 or comparable standard.In a further preferred embodiment, the matrix layers can have a thickness of at least 0.05 mm, preferably at least 1 mm and / or a maximum of 300 mm, preferably a maximum of 100 mm, particularly preferably a maximum of 40 mm.In a further possible embodiment, the object carrier can be part of the fiber composite component. In this embodiment, prefabricated components and / or component cores can serve as object carriers, for example. By applying matrix material to the prefabricated component, a direct connection of the matrix material to the prefabricated component can be achieved, so that connecting elements, such as welds, are omitted.In a further embodiment, the application unit can have an extrusion head, so that the matrix material can be applied by means of extrusion. During extrusion, complex shapes can be applied in strands. It is furthermore advantageous that brittle matrix materials which are solid or viscous can also be extruded, since these are pressed under pressure through a nozzle or a so-called die. Alternatively, the matrix material can also be applied droplet by droplet. It is advantageous that no high pressures are necessary in droplet-wise application, but solid and very viscous matrix materials can only be applied droplet-wise with difficulty.In a further possible embodiment, the application unit and / or the laying head can be movable independently of one another. This has the advantage that the fiber element can be applied to the fiber composite component to be produced independently of a travel path of the application unit. The application unit and / or the laying head are preferably mounted on a multiaxial geometry, wherein the multiaxial geometry preferably has 3, particularly preferably 6 axes.In a further embodiment, the fiber element can be preimpregnated with a liquid, for example an epoxy resin adhesive, before application to the matrix material. Preferably, the liquid may be an adhesive so that the fibre element can be bonded to the matrix material. Additionally or alternatively, the fiber element can be embedded in the matrix material before it is completely cured, so that the fiber element is partially or completely surrounded by matrix material. The component can thus also be reinforced in regions in which component loads occur in the interior of the component. Preferably, the applied fiber element can have a length of at least 0.5 mm, preferably at least 1 mm, in particular preferably at least 10 mm, and can contain at least one glass and carbon fiber. Glass and carbon fibers typically have high tensile elastic moduli greater than 70 GPa so that they can withstand high tensile loads.In a particularly preferred form, the short fibers which are embedded in the matrix material can have a length of at most 100 mm.In a further embodiment, the short fibers can be mixed with the matrix material in the application unit. An extrusion mixing head, for example, is particularly advantageous in which the process steps embed short fibers and apply matrix material can be carried out simultaneously. Thus, for example, a substantially homogeneous fiber distribution can be achieved. A homogeneous fiber distribution is advantageous in order to achieve a substantially homogeneous stability and component quality.Short fibers may be embedded in one or more layers of matrix material. In regions in which short fibers are embedded in the matrix material, the component elasticity and the tensile strength are increased as explained above. It is advantageous in this embodiment that short fibers can be embedded in regions in which component loads occur. Thus, the component to be produced can be adapted exactly to later loads with regard to weight and material consumption. Thus, no short fibers need to be embedded in layers in which no reinforcement is necessary.For the targeted use of short fibers in the component, short fibers can be applied between two layers of matrix material. The short fibers can also be applied between the fiber element and the matrix material. In a further embodiment, the short fibers can be preimpregnated with a liquid, for example with an adhesive.In a further advantageous embodiment, the short fibers can be embedded in the matrix material in a directed manner, i.e. a longitudinal axis of the short fibers has a direction determined before application, this direction preferably corresponds to the direction of the tensile loads of the fiber composite component. By means of a short-fiber laying head or another application unit, the short fibers can be embedded with their longitudinal axis into the matrix material along the travel path of the application unit of the matrix material. The short fibers have the highest tensile modulus of elasticity along their longitudinal axis. This embodiment has the advantage that the short fibers can be aligned in the direction of tensile stress and the component thus resists higher tensile stresses than in the case of disordered embedding of the short fibers.For a substantially homogeneous fiber distribution, a volume of the short fibers contained in the matrix material can be at least 10 vol. %, preferably at least 30 vol. %, in particular preferably at least 35 vol. % and / or at most 80 vol. %, preferably at most 70 vol. %, in particular preferably at most 60 vol. %, compared to a total matrix volume, wherein the total matrix volume is a sum of the volume of the embedded short fibers and a volume of the matrix material. A high proportion of short fibers in the matrix material has the advantage that the matrix material-short fiber mixture has an increased elasticity and can thus withstand higher tensile loads. It can also be provided that the proportion by volume of the short fibers in the total matrix volume is varied layer by layer during the application of matrix material, so that the fiber composite component preferably has regions with different short fiber volume proportions. This embodiment has the advantage that the fiber composite component to be produced can be adapted precisely to later loads with regard to weight and material consumption.Method step II can be carried out before method step III and / or method step III can be carried out before method step II. Depending on the requirement of the fiber composite component, the fiber element can be embedded in the matrix material or can be applied in a targeted manner to matrix layers after curing. This has the advantage that the fiber element can also be embedded in inner layers of the fiber composite component. Thus, the fiber element can also absorb tensile loads which occur in the interior of the fiber composite part.The subject matter of the application is also a fiber composite component which has the structure described in this application and has preferably been produced using the method according to the application. Further developments also result from the description of the exemplary embodiment.Advantageous embodiments of the invention are explained below with reference to the figures.The following are shown: FIG. 1 shows a flow diagram with method steps of a method for producing a three-dimensional, multilayer fiber composite component, FIG. 2 shows a perspective illustration of an application unit during application of matrix material, FIG. 3 shows a schematic illustration of an application unit during application of matrix material, FIG. 4 shows a layer structure of the fiber composite part in a section of a component cross section, FIG. 5 shows a layer structure of the fiber composite component with impregnated fiber elements in a section of a component cross section, FIG. 6 shows a layer structure of the fiber composite part with directed short fibers between two matrix layers, FIGS. 7 aand 7 b show different plan views of a fiber composite component with fiber element, FIG. 8 shows a schematic illustration of a production of a rotor blade, FIG. 9 shows a longitudinal section of the rotor blade, and FIG. 10 shows a cross section of the rotor blade.FIG. 1 shows a flow diagram with four steps of a method for producing a three-dimensional multilayer fiber composite component. The method steps are:applying 1 matrix material,embedding 2 short fibers,applying 3 a fiber element; and- curing 4.Arrows, one of which is exemplarily provided with the reference numeral 5, show different execution orders. The method may begin with method step 1, 2 or 3. In an exemplary embodiment, matrix material is first mixed with short fibers in an application unit, for example an extrusion mixing head. In the exemplary embodiment, the matrix material is thermosetting polyurethane, but the matrix material can also be another thermosetting matrix material, for example epoxy resin or formaldehyde resin. The short fibers are made of glass fiber in the example shown. The short fibers can also be other materials, for example made of carbon fiber or natural fiber, such as wood fiber. The matrix material is thixotropic in the example shown. The short fibers and the matrix material are each stored in a material storage. The matrix material is stirred through in the material reservoir, so that the viscosity of the matrix material is reduced due to its thixotropic nature. In the extrusion mixing head, the short fibers are mixed with the matrix material before application, before flowing out of an application nozzle. The matrix-short-fiber mixture is applied in a first layer by the extrusion head, for example by the application nozzle, to a slide, i.e. the extrusion mixing head follows a contour of the slide and extrudes a matrix-short-fiber mixture strand onto the slide. The matrix-short-fiber mixture strand, when applied, preferably has at least a length which corresponds to twice the width. The matrix-fiber mixture is cured after the application of a complete layer, for example by heating. After curing, a further strand of the matrix-fiber mixture is applied to the first strand. A fiber element is then placed on the second matrix layer by means of a laying head, so that the fiber element, for example a glass fiber trap, is at least partially surrounded by matrix-fiber mixture that has not yet fully cured. This is followed by a curing process of the matrix material, for example by heating. The method steps can be combined and repeated in any desired order. The matrix-fiber mixture can be applied in strands, but also in droplets. The object carrier can be, for example, a plate which supports the fiber composite part to be produced during the production process, but is not part of the component. The object carrier can also be part of the fiber composite component, for example in the form of a prefabricated component core, for example an additively prefabricated component core made of thermoset foam.FIG. 2 illustrates the method step of applying 1 matrix material 8. After leaving the opening 7, the matrix material is still in a viscous state. Droplets 9 are applied side by side, so that they connect and matrix layers 10 are formed. After the application of a matrix layer 10, the matrix material 8 cures, for example by heating. The matrix layers 10 form part of a component 11. Alternatively, the matrix material 8 can be applied in strands. The matrix material 8 can be, for example, a thixotropic material, for example thermosetting polyurethane.FIG. 3 shows an application unit when applying a layer. Repetitive features are denoted by the same reference numerals throughout this and the following figures. A part of an application unit 6 has an opening 7, through which matrix material 8 is dispensed in droplets. The matrix material 8 is applied to a slide 12. In the example shown, the object carrier 12 is not part of the component 11. Droplets 9 are applied side by side at a distance of, for example, 1 mm and then connect to the adjacently arranged droplets on the object carrier to form a matrix layer 10 on account of its liquid state. Additionally or alternatively, the matrix material 8 can be applied to the object carrier 12 in a strand-wise manner. In the example shown, the application unit 6 is designed as a nozzle 13. In further embodiments, the application unit 6 can be designed as an extrusion head and / or as an extrusion mixing head. In the extrusion mixing head, short fibers are mixed with the matrix material before application.FIG. 4 shows a detail of a component cross section. The component cross section shows five matrix layers 14- 18. In a first applied layer 14, a fiber element 19 is embedded in the matrix material 8. In the example, the fiber element 19 is completely surrounded by matrix material 8. In another embodiment, the fiber element 18 can be only partially surrounded by matrix material 8. The fiber element 18 is 6 cm long in the example shown. Short fibers-one of which is exemplarily provided with the reference numeral 20-are embedded in the matrix material 8 in the five layers 14 to 18. The short fibers 20 are embedded in the matrix layers 14 to 18 in a random direction distribution. In another exemplary embodiment, the short fibers 20 can also be embedded in the matrix material 8 in a directed and / or ordered manner, for example by their longitudinal axis lying along the travel path of the application unit. The short fibers contained in the matrix material have a proportion of, for example, vol. 30% of a total matrix volume, wherein the total matrix volume is the sum of matrix material volume and short fiber volume. This material mixture, for example thermosetting polyester resin with short glass fiber, brings about, for example, a high elasticity, for example a tensile modulus of elasticity of 14 GPa, with at the same time a high bending strength, for example 120 MPa, of a fiber composite component to be produced.FIG. 5 shows a detail of a component cross section. The component cross section shows five matrix layers 21 to 25; two fiber elements 19 are applied to the first layer 21. The fiber elements 19 are surrounded by a liquid, in this exemplary embodiment by an adhesive 26, for example an epoxy resin. In other embodiments, the liquid may be another liquid. Short fibers 20 are embedded in the matrix material 8 in the second layer 22 and in the third layer 23. No short fibers 20 or fiber elements 19 are embedded in the first layer 21 and the fourth 24 and fifth layer 25.FIG. 6 shows a section of a fiber composite component illustrating a three-layer application of matrix material 8 and short fibers 20. Directional short fibers 20 form a middle layer. The matrix material 8 can be, for example, duromer polyurethane. The short fibers can be, for example, glass fibers, in particular E-glass fibers. An application unit 6, for example an extrusion laying head, applies a layer of matrix material 8 to a specimen slide 12, for example a steel plate. In the example shown, the matrix material is cured in a next method step, for example by heating. In the example shown, the application unit 6 then applies a plurality of short fibers 20, for example glass fibers, in particular E glass fibers, to the first layer of matrix material 8. The short fibers 20 are laid onto the first matrix layer in a directed manner, pointing parallel along their longitudinal axes and pointing along their longitudinal axis in the direction of a tensile loading direction of the fiber composite component. The tensile modulus of elasticity of the E-glass fiber is, for example, 70 GPa. In a further method step, a second layer of matrix material 8 is applied to the short fibers 20 and cured by the application unit 6. In the example shown, the matrix material 8 of the second matrix layer encloses the applied short fibers 20.In another embodiment, short fibers 20 can also be applied to the applied matrix layer without the method step of curing, so that these are already embedded in the first applied matrix layer. In another embodiment, the matrix material can be stronger, so that the second applied layer of matrix material 8 remains on the short fibers and does not completely enclose the short fibers.FIG. 7 ashows a top view of a fiber composite component 27. Fibre elements 19a, 19b and 19c are applied to the fibre composite part 27. The fiber elements 19a and 19c are applied in a straight line. The fiber element 19 bis applied in meandering fashion. Four fiber elements are applied in parallel in straight strands. The fiber elements, for example glass fiber, carbon fiber or natural fiber, have tensile elastic moduli of between 70 and 400 GPa. This brings about a high elasticity of the fiber composite component 27 in the regions in which fiber elements are applied in the direction of tensile loading. By means of a free-form application, i.e. by means of an arbitrarily selectable form of the application geometry, tensile loads in different directions of the fiber composite component 27 can be absorbed, as shown in the example. The fiber elements 19 a, 19 band 19 care applied in different regions of the fiber composite part.FIG. 7 b shows a further plan view of a fiber composite component 27 with a fiber element 19. In the present exemplary embodiment, the fiber element 19 is applied in a curved manner to the matrix material 8. The fiber element 19 does not overlap. In other exemplary embodiments, the fiber element 19 can also be arranged overlapping itself. The fiber element 19 contains, for example, carbon fiber and / or glass fiber, but can also contain other materials such as, for example, natural fibers such as, for example, sisal, kenaf, hemp or similar long fibers. The fiber element 19 has a length of 16 cm, for example. In addition, an application unit 6 and its travel path 28 are shown. The fiber element 19 is applied by a laying head 29. A travel path of the laying head 29 corresponds to the shape of the applied fiber element 19 and does not necessarily correspond to the travel path 28 of the application unit 6 of the matrix material 8. The laying head 29 and the application unit 6 can be arranged in parallel. The laying head 29 and the application unit 6 can be arranged, for example, on a multiaxial geometry. The multiaxial geometry preferably contains 3 axes, in particular preferably 6 axes. The laying head 29 and the application unit 6 can move independently of one another on the multiaxial geometry.FIG. 8 shows a schematic illustration of a production of a rotor blade 30 of a wind turbine. The rotor blade is a substantially circular ring-shaped, hollow component in the area of the rotor hub i. An application unit 6 applies matrix material 8 in layers to an object carrier 12. In this exemplary embodiment, the application unit 6 traverses a circular path, wherein the circles traversed are concentric with the circular ring of the rotor blade, and coats matrix material 8 in layers. With increasing number of layers, however, the web can also assume the geometry of a rotor blade cross section, i.e. become elliptical or streamline. In the example shown, a laying head 29 carries a fiber element 19 in regions onto already applied matrix layers of the circular ring. The fiber element 19 is applied with a curvature that corresponds to a curvature of the circular ring of the rotor blade. In the example shown, the matrix material 8 is cured after the application of a layer by the application unit and after the fiber element 19 has been embedded. The fiber element is surrounded by matrix material 8, but in a further exemplary embodiment can also be surrounded only partially by matrix material 8. Due to the curing of the matrix material 8 after embedding the fiber element, no additional adhesive is necessary for fixing the fiber element 19, since the matrix material 8 fixes the fiber element 19 in the matrix layer during curing. In this exemplary embodiment, the object carrier 12 is not part of the fiber composite component. The matrix material 8 can be mixed with short fibers which have been embedded in the matrix material, for example, before the application of the matrix material. The short fibers can be, for example, UMS carbon fibers that have a tensile modulus of elasticity of 395 GPa. This has the advantage that an elasticity of the rotor blade 30 is increased in regions of the short fibers 20 mixed with the matrix material 8.FIG. 9 shows a longitudinal section of a rotor blade 30 of a wind turbine. The longitudinal section lies in the xz plane. The section of the rotor blade in longitudinal section has the shape of an extruded semi-circular ring which points with the inside of the circle upward (in the y direction). Two trapezoidal stabilization webs 31, for example made of thermosetting polyurethane, are attached to the rotor blade 30. The stabilization webs 31 are parallel to one another in their longitudinal axis and are arranged parallel to the longitudinal axis of the rotor blade 30 in their longitudinal axis. The stabilization webs reinforce the rotor blade 30 and increase bending and torsional rigidity. In order to increase a tensile strength, in the example shown, fiber elements 19, for example made of E-glass fiber, are applied to the rotor blade 30 in various regions. In the example shown, two fiber elements 19 are applied to the inner lateral surface of the rotor blade on one side of the stabilization webs 31 in each case. A further fiber element 19 is embedded in the matrix material 8, for example, on the cut edge along the longitudinal axis of the rotor blade opposite the z-direction.In FIG. 10, a cross section of the rotor blade 30 of the wind turbine is shown. The cross section runs through the xy plane. In this exemplary embodiment, the component has, for example, a thermoset foam core 32, for example made of thermoset polyurethane foam. In another example, a fiber composite component, in this example a rotor blade 30, can have a component core made of another material. In the example shown, the duromer foam core 32 serves as a slide, so that matrix material is applied additively around the foam core 32. An application unit comprises, for example, a 6-axis geometry on which, for example, an extrusion mixing head can move with 6 degrees of freedom and applies a matrix-short-fiber mixture 33, for example an epoxy resin-glass fiber mixture, layer by layer to the duromer foam core 32 following the contour of the duromer foam core 32. The foam core 32 can also be additively applied in the same method as the matrix-short-fiber mixture 33 enclosing the foam core 32 in another embodiment. The fiber element 19, for example made of carbon fiber, in particular of HT carbon fiber, is each elongated and rectilinear. The tensile modulus of elasticity of the HT fiber is about 230 GPa and reinforces the rotor blade 30 with respect to tensile loads in the longitudinal direction of the applied fiber element 19.

Claims

Method for producing a three-dimensional, multilayer fibre composite component (11), wherein the method comprises the steps of I. applying a curable matrix material (8) layer by layer to an object carrier (12) in matrix layers arranged one above the other by at least one application unit (6) movable relative to the object carrier (12), wherein matrix material (8) which has been applied in one layer forms a matrix layer, II. applying at least one fibre element (19) at least in regions, in a strand-by-strand manner to at least one of the matrix layers by at least one laying head movable relative to the object carrier (12), III. curing the matrix material (8), wherein the matrix material (8) is a thermosetting plastic and short fibres (20) are embedded in the thermosetting plastic, wherein the short fibres (20) have a shorter length than the applied fibre element (19), characterized in that, the matrix material (8) is alternately a fibrous matrix or a thermoset foam layer by layer.Method according to claim 1, characterised in that the matrix material is thixotropic.Method according to one of the preceding claims, characterized in that the matrix layers have a thickness of at least 0.05 mm and at most 300 mm.Method according to one of the preceding claims, characterized in that the object carrier (12) is part of the fibre composite component (11).Method according to one of the preceding claims, characterized in that the application unit (6) has an extrusion head.Method according to one of the preceding claims, characterized in that the application unit (6) and / or the laying head (29) can be moved independently of one another.Method according to one of the preceding claims, characterized in that the fibre element (19) contains at least one glass and / or carbon fibre.Method according to one of the preceding claims, characterized in that the applied fibre element (19) has a length of at least 0.5 mm.Method according to one of the preceding claims, characterized in that the fibre element (19) is preimpregnated with a liquid (26) before application to the matrix material (8).Method according to one of the preceding claims, characterized in that the fibre element (19) is at least partially embedded in the matrix material (8).Method according to one of the preceding claims, characterized in that the short fibres (20) which are embedded in the matrix material have a length of at least 0.5 mm and at most 100 mm.Method according to one of the preceding claims, characterized in that the short fibres (20) are mixed with the matrix material (8) in the application unit (6).Method according to one of the preceding claims, characterized in that short fibres (20) are / are embedded in one or more layers of matrix material (8).Method according to one of the preceding claims, characterized in that short fibres (20) are applied between two layers of matrix material (8).Method according to one of the preceding claims, characterized in that the short fibers (20) which are embedded in the matrix material (8) are embedded in the matrix material (8) in a directed manner and lie with their longitudinal axis along the travel path (28) of the application unit of the matrix material.Method according to one of the preceding claims, characterized in that a volume of the short fibres (20) contained in the matrix material (8) is at least 10% compared to a total matrix volume, wherein the total matrix volume is a sum of the volume of the embedded short fibres (20) and a volume of the matrix material (8).Method according to one of the preceding claims, characterized in that, in at least two layers, a volume of the short fibres (20) contained in the matrix material (8) is different from a total matrix volume, wherein the total matrix volume is a sum of the volume of the embedded short fibres (20) and a volume of the matrix material (8).Method according to one of the preceding claims, characterized in that step II is carried out before step III and / or step III is carried out before step II.Component produced by a method according to one of the preceding claims.

Images