CN1849208A - Force-introduction point in core composites and method for producing said point using reinforcement elements that traverse the thickness of the core composite - Google Patents

Abstract

The invention relates to the configuration and production of force-introduction points in core composites using reinforcement elements that traverse the thickness of said core composite. The reinforcement elements that traverse the thickness of the core composite are provided in the vicinity of the force-introduction points. The reinforcement elements (e.g. stitched fibres) are preferably incorporated by means of a stitching process and a stitching needle. After the stitching process, the cover layers (a and c), which preferably consist of textile semi-finished products and the hole produced by the passage of the needle, together with the reinforcement element are impregnated with a liquid polymer matrix, creating the material union of the core material and the cover layers.

Description

Force transmission location in core composite and method for producing the same by reinforcing elements penetrating in thickness direction of core composite

technical field

The invention relates to a structure and a method for producing force transmission points in a core composite by means of reinforcing elements penetrating through the thickness of the core composite according to the preamble of claim 1 .

Background technique

The invention is suitable for introducing forces and moments into core composite structures. The core composite structure may preferably consist of a textile semi-finished cover layer (1 and 3, such as fabric or gauze (Gelege), mat, etc.), a core material (2, such as a polymeric foam material) and a polymeric matrix material (thermoplastic or thermosetting plastics) fiber-plastic composites. The core composite is a layered structure consisting of a relatively thin upper cover layer 1 and a lower cover layer 3 and a relatively thick core layer 2 with low bulk density. Due to the thin cover layers and the low tensile (Zugweich) and compressive (Druckweich) properties of the core material, the core composite structure is essentially very sensitive to locally introduced force or moment loads. The introduction of forces into the core composite structure must therefore be adapted to the load, material and processing technology. The resulting multiaxial load states at the force transmission points can no longer be taken up by the covering layer, which is only subjected to surface loads (tension, compression, shear). The structural measures required for this at the force transmission point depend on the point of application and direction of the force and the resultant force. The introduction of force is therefore usually carried out in such a way that no local instabilities (for example twisting or buckling of the covering layer) occur, the core layer and the covering layer are not damaged, and the force transmission element does not become detached from the core composite structure. The prerequisite for this is that the forces and moments introduced into the core composite structure are distributed over as large a surface as possible and uniformly. All structural measures for introducing forces into the layered structure have in common, therefore, that they lead to a reduction of the local stress level by increasing the force introduction area and the cross-sectional area. Furthermore, in some applications the less compressive core material must be replaced by a compressive material in the region of the force transmission point, so that for example the prestressing of the screw connection can be absorbed.

For the introduction of forces and moments into the core composite, additional installed force-transmitting elements (so-called outer inserts) or inserted force-transmitting elements (so-called inner inserts) can be used. Furthermore, it is possible to remove the core material in the region of the force transmission point and to put the two covering layers together, so that there is a single fiber-plastic composite region without the need for additional force transmission elements. Self-tapping screws or screw inserts as well as riveting can also be used as alternative force transmission options for the core composite structure, but they can only transmit small forces and moments. Force transfer points are always required if forces and moments are to be introduced into or derived from a structure and if structural components are to be connected to each other. Core composite structures of fiber-plastic composites are commonly used, for example, in aeronautics and aerospace, in rail vehicle construction and automobile construction, and in shipbuilding.

All known force-transmitting elements (outer inserts) for the installation of core composite structures made of fiber-plastic composites are bonded materially to one of the two covering layers. All these force introduction solutions have the following common disadvantages. The two covering layers are exposed to very different loads, ie the covering layer with the installed outer insert is subjected to much greater loads than the opposite covering layer. This can lead to delamination between the outer insert and the cover layer or between the cover layer and the core layer. Furthermore, the soft tensile and low compressive core material is not sufficiently reinforced below the outer insert, so that the core material is exposed to high loads and can lead to failure of the core material. In order to avoid failure of the core layer below the outer insert, in some solutions it is completely replaced in the area of the force transmission points by another material with high mechanical properties.

All known additional embedded force-transmitting elements (interposers) are connected in a materially bonded manner to the core composite structure. In this case, the interposer can be positioned within the cover layer, between the cover layer and the core layer or within the core material. Due to a purely material-locked connection, locally acting forces or moment loads may cause the interposer to separate from the entire core composite structure due to adhesive failure, which may result in a complete failure of the force input or a gap between the cover layer and the core layer. delamination.

All known force introduction concepts for core composite structures without additional force transmission elements have in common that in the region of the force transmission point first the core material is removed or compressed and the two covering layers are brought together together, there is thus a single region of a single reinforcement layer made of fiber-plastic composite. A pin connection can then be placed in a single area. In this case, with all known solutions, failure of the covering layer in the joined area or core failure outside the joined area or delamination between the covering layer and the core layer is caused, because these areas are in the core composite. There is no additional force-locked and material-bonded core composite structural reinforcement in the thickness direction of the structure.

Laid-open documents DE 100 02 281 A1 and EP 1 106 341 A2 disclose the possibility of introducing force for core composite structures by joining the cover layers together without additional force-transmitting elements. However, in these inventions no force-fitted and material-bonded structural reinforcement of the core composite is achieved inside or outside the region where the cladding layers are joined, so that neither the resistance against delamination between cladding and core layers can be improved (peel strength) and the core layer also has no reinforcements. The typical failure behavior, delamination between cover layer and core layer and core failure in the region of the force transmission point, cannot therefore be improved by the two known methods.

In publication US 005741574A it is disclosed how a pinned connection can be reinforced by means of a fiber reinforcement embedded in the core. This invention involves, first embedding the fiber strands inside the entire core material. The textile cover layer is then placed on the core material and subjected to pressure, whereby the core material is compressed and the thread can be pushed into the cover layer. Impregnation of the core composite structure is then achieved by a liquid thermosetting resin system. This is followed by a hardening process of the resin system. A through hole for the pin connection is embedded in the hardened core composite structure. In this case, the fiber threads in the core material are able to withstand the prestressing of the screw connection and prevent delamination tendencies between the cover layer and the core layer in the region of the force transmission point. In this invention, there is only a material-fitting connection between the fiber threads and the entire core composite structure in the force-transmitting region, and there is no force-fitting and form-fitting connection, thus in contrast to a force-fitting and form-fitting connection. A locked connection only slightly increases the resistance against delamination between the cover layer and the core layer. Another disadvantage of this invention is that the entire core material of the core composite structure has sewing threads. As a result, the force transfer points are not necessarily and additionally reinforced compared to the rest of the core composite structure, so that the undisturbed core composite structure and the force transfer points are loaded very differently and the core composite structure is not fully utilized potential for lightweight construction. Furthermore, the core material is open in the region of the through-holes, so that liquid or gaseous media can be forced into the core material. These intruded media can negatively change the properties of the core material and even lead to failure.

In laid-open document DE 198 34 772 C2 a method for connecting an additionally inserted force-transmitting element (interposer) is disclosed, which has a fiber-reinforced structure consisting of a single reinforcement layer. In this case, the insert is positioned between the individual reinforcement layers and stitched by means of sewing threads in the thickness direction of the fiber-reinforced structure. The disclosed solution for connecting an interposer into a single reinforcement structure consisting of a single reinforcement layer is also applicable to core composite structures. Here, the insert is inserted between the individual reinforcement layers of one of the two covering layers and sewn with the aid of sewing threads. Both the covering layer including the stitched-on interposer and the other covering layer are then placed on the core layer. By means of the liquid impregnation process, the cover layer can be wetted with a polymeric matrix material and an adhesive connection can be produced between the cover layer and the core layer, so that a core composite structure of fiber-plastic composite is obtained. The application of the disclosed invention to the core composite structure has only one effect of producing a non-positive and form-fitting connection between the inner insert and the cover layer by means of sewing threads. As a result, neither the resistance to delamination between the cover layer and the core nor the reinforcement of the low-tensile and compressive core material in the area of the force-transmitting points can be improved, and thus the two typical aspects of the core composite structure cannot be improved. failure form. A further disadvantage of the invention is that when forces and moments are introduced into the interposer, the covering layer on which the interposer is located is subjected to significantly greater loads than the other covering layer, so that the lightweight construction potential of the core composite cannot be fully utilized . Furthermore, a force flow must be achieved from one cover layer through the core material, which has low mechanical properties compared to the material of the cover layer, to the other cover layer and which is a weak point in the core composite structure. As a result, the core material can be subjected to very high loads and failure of the core material can be triggered. The strength and stiffness of the force transfer points or of the entire core composite structure is thus mainly influenced by the low mechanical properties of the core material.

All currently known force introduction solutions for core composite structures have in common the fact that the core composite structure is not sufficiently reinforced in the area of the force transmission points, so that due to excessive tensile, compressive or Shear stress and delamination between the cladding and core layers can produce core failure. Furthermore, in all known solutions for additionally mounted or embedded force-transmitting elements, there is no constructive non-positive and form-fit connection of the force-transmitting element to the entire core composite. Consequently, neither detachment of the force transmission element from the core composite structure nor delamination between the cover layer and the core layer or between the force transmission element and the cover layer can be prevented.

Contents of the invention

The object of the invention is to improve the mechanical properties of the force transmission points in the core composite by inserting reinforcing elements in the thickness direction (z-direction) of the core composite structure ( FIGS. 1 a and 1 b ).

This object is achieved by splitting the covering layers of the core composite and/or providing a force-transmitting element in the core composite in the region of the force-transmitting point, and by piercing the core composite in the thickness direction at the force-transmitting point Transparent reinforcement elements provide reinforcement for the core composite structure. The upper covering layer, the core layer and the lower covering layer are connected in a non-positive and form-fitting manner by means of the stiffening element in the region of the force transmission point. Furthermore, the force transmission element can be fastened to the core composite by means of a reinforcing element. A textile reinforcement ( 4 , such as sewing threads, fiber strands, glass strands, etc.) can preferably be used as the reinforcement element. The invention relates to a core composite with covering layers 1 and 3, preferably composed of textile semi-finished products (such as braids, gauze or knitted fabrics, mats, etc.), and having a core layer 2, preferably made of polymeric rigid foam constituted, and optionally has a matrix material, preferably composed of a polymeric material (thermoplastic or thermosetting plastic). The core composite structure can be made by one of a number of liquid composite molding (LCM) processes, such as resin injection or resin infiltration processes. This type of core composite structure is reinforced in the thickness direction by means of a textile reinforcement in the force-transmitting region before being impregnated with the polymeric matrix material. Such a reinforced force transmission point can be produced, for example, by industrial sewing techniques. The incorporation of reinforcing structures, preferably sewing threads, in the thickness direction of the core composite can be achieved, for example, by means of sewing needles. Here the sewing needle penetrates the entire core composite structure and leaves a through hole for the polymeric rigid foam core material including the reinforcement structure. In this case, the cross-sectional area of the through-opening must be sufficiently large compared to the cross-sectional area of the reinforcing structure, so that the reinforcing structure can be wetted with the polymeric matrix material and connected to the core layer in a form-fitting manner. The stiffening element may have an angle of 0° relative to the direction of the z-axis in the thickness direction of the core composite structure in the xz or yz plane ( FIGS. 1 a and 1 b ), e.g. An angle of +/- 45° between the z axes and/or between the y and z axes is recommended. After the force transfer points and the entire core composite structure have been completely reinforced by the reinforcement structure, the textile cover and the through-holes including the reinforcement structure are impregnated with the polymeric matrix material in the LCM process, wherein a material lock of the core material and the cover layer is simultaneously achieved combined connection. After the hardening of the core composite structure is completed, the textile reinforcement structure wetted with the polymer matrix material forms a unidirectional fiber-reinforced tension/compression rod inside the core material, which acts as a reinforcement force transmission position, the core material and the entire The role of the core complex. The role of this reinforcing structure here is to increase the peel strength between the force-transmitting element and the core composite structure and between the cover layer and the core layer, prevent the force-transmitting element from separating from the core composite structure, and improve the core material. Mechanical properties (characteristic values of strength and rigidity in the thickness direction). The textile reinforcement can block or deflect cracks existing in the critical region of the cover layer and the core layer. The failsafe behavior of the force transmission points of the core composite can thus be improved. By adding a textile reinforcement structure in the thickness direction of the core composite structure in the area of the force transmission location, the compressive and tensile strength perpendicular to the plane of the core composite can be increased compared with known conventional force introduction solutions, increasing the Increased compressive and tensile stiffness perpendicular to the plane of the core composite, improved compressive strength in the plane of the core composite, increased shear strength and stiffness, and increased strength between the cladding and the core and force-transmitting elements Peel strength from the covering layer. Furthermore, the failure behavior can be improved by the increased peel strength and by the "crack blocking function" of the individual reinforcing elements, so that impact failure due to force introduction can be prevented and thus a so-called fail-safe behavior can occur. The force-transmitting element can be connected to the core composite structure in the correct position by means of industrial sewing techniques. The mass reliability of the force transmission point in the core composite can be guaranteed by the addition and presence of a certain number of reinforcing elements. A further advantage of the invention is that the stiffening element can protrude beyond the force-transmitting point into the core composite structure surrounding the force-transmitting point, so that greater forces and moments can be introduced into the core composite structure.

In order to eliminate the need for additional force-transmitting elements, which would have a negative effect on the weight of the core composite structure, core material can be removed or compressed in the region of the force-transmitting points, thereby allowing the cover layers to be joined together. A further advantage can thus be achieved in that the force transmission element has one or more flanges, whereby forces and moments can be introduced into the core composite structure via a larger surface.

In order that the force transmission element can be connected in a force-fit and form-fit manner to the entire core composite in the region of the force transmission point, the force transmission element has a bore for receiving the reinforcement element. In this way, detachment of the force transmission element can be prevented and the peel strength between the force transmission element and the core composite structure can be increased. If it is necessary to avoid penetration of at least one covering layer of the core composite due to technical requirements for structural parts of the core composite (eg hull in shipbuilding), it is possible to arrange force-transmitting elements (so-called outer inserts) between two covering layers. Layers on one of the overlays or set on both overlays.

In order to be able to transmit greater forces and moments into the core composite structure, the force-transmitting element (so-called insert) can also be arranged in one of the two covering layers or within both covering layers . Furthermore, the force-transmitting element can be positioned between two covering layers, thereby partially or completely penetrating the core material.

Another advantage can be achieved by the application-dependent geometrical and structural configuration of the force-transmitting element, that is, by the force-transmitting element having one or more projections which bear against the covering layer or the covering layers. In part, the introduction of forces and moments can thus be improved due to the larger lever arm.

The invention creates a reinforcement possibility for the type of force transmission point in the core composite, in which the core material is removed or compressed in the region of the force transmission point and the two covering layers are brought together so that a single fiber-plastic composite is present object area. Here, the upper covering layer 1 is connected to the lower covering layer 3 in the region of the force transmission points 5 by piercing reinforcing elements 4 inserted in the thickness direction of the core composite structure by means of sewing techniques ( FIGS. 1 a and 1 b ). Furthermore, the stiffening element 4 can project beyond the force transmission point 6 into the core composite structure surrounding the force transmission point in order to absorb higher forces and moments and to improve the mechanical properties ( FIG. 1 c ). The reinforced force transmission can be established by one of the many LCM processes without the need for force transmission elements for the core composite comprising the covering layers (1 and 3) of the textile semi-finished product, a core material 2 and polymeric matrix material. In a working step preceding the addition of the polymeric matrix material, the core material is first removed or compressed in the region of the force transmission point. The two cover layers are then joined together and the upper cover layer 1, the core material 2 and the lower cover layer 3 are passed through the textile reinforcement structure 4 in the core composite structure thickness in the force transmission area 5 and if necessary beyond the force transmission area 6 The direction is sewed to each other by means of sewing techniques. The core composite structure including the textile reinforcement structure is then impregnated and hardened with a polymeric matrix material (eg thermoset or thermoplastic) in an LCM process (eg resin injection or resin infiltration process).

It is also possible to use a force transmission element (outer insert, 7 ) attached to the core composite structure for the transmission of forces and moments ( FIGS. 2 a and 2 b ). The outer insert is placed on one of the two covering layers ( FIGS. 2 a to 2 f ) or on both covering layers ( FIG. 2 g ) and is anchored to the core composite structure by means of reinforcing elements 4 in the region of the force transmission point. It is connected with the whole core composite structure in the thickness direction. The outer insert has holes 8 for receiving reinforcement elements. The outer insert can have a laterally protruding flange 9 ( FIG. 2 c ), which is arranged on the upper cover layer 1 or the lower cover layer 3 and which also has holes 8 for receiving reinforcement elements. For better transmission of forces and moments, the reinforcing elements 4 can be inserted into the core composite structure beyond the outer insert or the flange of the outer insert 10 in the thickness direction of the core composite structure ( FIG. 2 d ). Furthermore, the flange of the outer insert can have one or more projections 11 ( FIGS. 2 e and 2 f ) for better transmission of forces and moments into the core composite structure. In a working step prior to the addition of the polymeric matrix material, the outer insert 7 and the core composite structure are joined to each other by means of industrial sewing techniques in the region of the force-transmitting points via the textile reinforcement structure 4 in the thickness direction of the core composite structure. stitching. The cover layer, core layer and textile reinforcement are then impregnated with polymeric material and cured in the LCM process.

The force transmission point with a force transmission element (interposer, 12) inserted into the core composite structure can thus be reinforced so that the upper cover layer 1, the core material 2 and the lower cover layer 3 are outside the area of the insert The reinforcement elements 4 are interconnected in the thickness direction of the core composite structure ( FIGS. 3 a and 3 b ). A method for producing a force-transmitting point for a core composite comprising cover layers 1 and 3, a core material 2 and a polymeric matrix material of a textile semi-finished product by means of an inserted force-transmitting element 12, the method providing that, In a working step prior to the addition of the polymeric matrix material, the upper cover layer 1, the core material 2 and the lower cover layer 3 are inserted in the thickness direction of the core composite structure by means of sewing techniques outside the force-transmitting position. The textile reinforcing structures 4 are sewn together. After adding the reinforcement structure, the core composite structure is impregnated with polymeric material and allowed to harden in one of the possible LCM processes.

The insert 12 can also be connected to the core composite structure in the thickness direction of the core composite structure by means of reinforcing elements 4 ( FIGS. 4 a and 4 b ). For this purpose, the insert has holes 13 for receiving reinforcing elements. Furthermore, the interposer can have a laterally protruding flange 14 ( FIG. 4 c ), which can be located inside the cover layers 1 and 3 , in the core layer ( 2 , FIG. 4 c ) or between the cover layer and the core layer. between them and have holes 13 for accommodating the textile reinforcing structure. The interposer can also have two laterally protruding and spaced apart flanges 14 (Fig. 4d), which can be arranged inside the two covering layers (1 and 3), on the core layer (2, Fig. 4d) or between the cover layers 1 and 3 and the core layer 2, and has holes 13 for receiving reinforcing elements. For a better transmission of forces and moments, these reinforcing elements 4 can be inserted into the core composite structure beyond 15 of the insert 12 or the flange 14 of the insert in the thickness direction of the core composite structure ( FIG. 4 e ). For better transmission of forces and moments into the core composite structure, the flange of the insert can have one or more projections 16 ( FIGS. 4 f and 4 g ). A method for producing force-transmitting points for a core composite comprising cover layers 1 and 3 of a textile semi-finished product, a core material 2 and a polymeric matrix material by means of an added force-transmitting element 12, the method providing that, in the In a working step prior to the addition of the polymeric matrix material, the insert is stitched to the core composite structure by means of sewing techniques through the textile reinforcement structure 4 inserted in the thickness direction of the core composite structure. After adding the reinforcing structure, the core composite structure including the reinforcing structure and the interposer is impregnated with a polymeric material and allowed to harden in one of the possible LCM processes.

Description of drawings

Describe the present invention below by means of 13 embodiments, in the accompanying drawings:

Figure 1a shows a bottom view of the first embodiment;

Figure 1b shows a sectional view along the line A-A in Figure 1a;

Fig. 1c shows a sectional view along the line A-A in Fig. 1a, with a second variant for implementing a reinforcing element;

Figure 2a shows a top view of a third embodiment;

Figure 2b shows a sectional view along the line B-B in Figure 2a;

Figure 2c shows a sectional view along the line B-B in Figure 2a, with another variant for constructing the outer insert;

Figure 2d shows a sectional view along the line B-B in Figure 2a;

Figure 2e shows a top view of a sixth embodiment;

Figure 2f shows a cross-sectional view along line C-C in Figure 2e;

Figure 2g shows a top view of a seventh embodiment;

Figure 2h shows a cross-sectional view along line D-D in Figure 2g;

Figure 3a shows a top view of an eighth embodiment;

Figure 3b shows a sectional view along the line E-E in Figure 3a;

Figure 4a shows a top view of a ninth embodiment;

Figure 4b shows a sectional view along the line F-F in Figure 4a;

Figure 4c shows a sectional view along the line F-F in Figure 4a, with another variant for constructing the interposer;

Figure 4d shows a sectional view along the line F-F in Figure 4a, with another variant for constructing the interposer;

Figure 4e shows a sectional view along the line F-F in Figure 4a, with a force-transmitting element (12, interposer) embedded in the core composite structure;

Figure 4f shows a top view of a thirteenth embodiment;

Fig. 4g shows a cross-sectional view along line G-G in Fig. 4f.

Detailed ways

Figure 1a shows a bottom view of a first embodiment comprising a force-transmitting location in a core composite with split covering layers 1 and 3, a core material 2 removed in the force-transmitting area and comprising Reinforcement elements 4 penetrating through the thickness of the core composite in the area of force transmission points 5 .

Fig. 1b shows a sectional view along the line A-A in Fig. 1a.

Figure 1c shows a sectional view along the line A-A in Figure 1a, with a second variant for the implementation of stiffening elements, wherein said stiffening elements 4 extend beyond the force transmission point 6 to the core composite structure surrounding the force transmission point middle.

Figure 2a shows a top view of a third embodiment with a force-transmitting element (7, outer insert: Onsert) placed on the upper cover layer 1 of the core composite structure, which is reinforced in the area of the force-transmitting point The elements 4 are connected to the entire core composite structure in the thickness direction of the core composite structure and have holes 8 for receiving the reinforcing elements 4 .

Fig. 2b shows a sectional view along line B-B in Fig. 2a.

Figure 2c shows a sectional view along the line B-B in Figure 2a, with a further variant for constructing an outer insert with a laterally protruding flange 9 (Figure 2b), which is arranged in on the upper cover layer 1 and likewise has holes 8 for accommodating reinforcing elements.

Figure 2d shows a sectional view along the line B-B in Figure 2a, with a further variant for implementing stiffening elements 4 extending beyond the force transmission point 10 to the core composite structure surrounding the force transmission point middle.

Figure 2e shows a top view of a sixth embodiment with a force-transmitting element (7, outer insert) placed on the upper cover layer of the core composite structure, which has a protruding portion 11 for better distribution of force and Moments are transmitted into the core composite structure.

Figure 2f shows a cross-sectional view along line C-C in Figure 2e.

Figure 2g shows a top view of a seventh embodiment with two force-transmitting elements (7, outer inserts) placed on the upper cover layer 1 and the lower cover layer 3 of the core composite structure, the two outer inserts In the region of the force location, the reinforcement element 4 is connected to the entire core composite structure in the thickness direction of the core composite structure and has holes 8 for receiving the reinforcement element 4 .

Figure 2h shows a cross-sectional view along line D-D in Figure 2g.

Figure 3a shows a top view of an eighth embodiment with a force-transmitting element (12, Insert: Insert) embedded in the core composite structure, wherein the Insert is placed between the two covering layers 1 and 3 of the core The interior of the core material 2 of the composite structure, while the upper cover layer 1 , the core material 2 and the lower cover layer 3 are connected to each other in the thickness direction of the core composite structure by reinforcing elements 4 outside the insert region.

Fig. 3b shows a sectional view along line E-E in Fig. 3a.

Figure 4a shows a top view of a ninth embodiment with a force-transmitting element (12, insert) embedded in the structure of the core composite, wherein the insert is placed between the two covering layers 1 and 3 of the core composite The interior of the core material 2 of the structure and has holes 13 for receiving reinforcement elements 4 and is connected with the core composite structure in the thickness direction of the core composite structure by means of the reinforcement elements.

Figure 4b shows a sectional view along line F-F in Figure 4a.

FIG. 4c shows a sectional view along the line F-F in FIG. 4a, with a further variant for the construction of the insert, wherein the insert has a laterally protruding flange abutting against the upper cover layer 1 disc 14, and has holes 13 for receiving reinforcement elements 4, and is connected to the core composite structure in the thickness direction of the core composite structure by means of the reinforcement elements.

Figure 4d shows a sectional view along the line F-F in Figure 4a, with a further variant for the construction of the interposer, wherein the interposer has two laterally protruding abutments against the upper cover layer 1 and the lower The flange 14 on the cover layer 3 has holes 13 for receiving the reinforcement elements 4 and is connected to the core composite structure in the thickness direction of the core composite structure by means of the reinforcement elements.

Figure 4e shows a sectional view along the line F-F in Figure 4a, with a further variant for the construction of the stiffening element, wherein the stiffening element 4 protrudes beyond 15 beyond the force transmission point to the core composite structure surrounding the force transmission point middle.

Figure 4f shows a top view of a thirteenth embodiment with a force-transmitting element (12, insert) embedded in the core composite structure, wherein the insert has a laterally protruding flange 14, the The flange has an overhang 16 for better transmission of forces and moments into the core composite structure and rests against the upper cladding 1 with holes 13 for accommodating stiffening elements 4 and by means of The reinforcing elements are connected to the core composite structure in the thickness direction of the core composite structure.

Fig. 4g shows a cross-sectional view along line G-G in Fig. 4f.

Claims (14)

1. the power transmission position in the core complex, it is characterized in that, each cover layer of amalgamation core complex (1 and a 3) and/or force transfer element (7 and 12) is set on this power transmission position, and, for the core complex structure reinforcing is set by the fastening element (4) that on the thickness direction of core complex, penetrates in this power transmission position.

2. the power transmission position in the core complex as claimed in claim 1 is characterized in that, (6,10 and 15) reached in the core complex structure that surrounds the power transmission position beyond described fastening element (4) exceeded the power transmission position.

3. as the power transmission position in each described core complex in the claim 1 to 2, it is characterized in that, described cover layer (1 and 3) is made up of the weaving semi-finished product, sandwich layer (2) is made up of core material polymerization, natural or that form structure, and fastening element (4) is made up of a kind of weaving ruggedized construction, and described cover layer, sandwich layer and fastening element are set in a kind of matrix material of polymerization.

4. as the power transmission position in each described core complex in the claim 1 to 3, it is characterized in that described core material (2) is removed or compresses in the power transmission band of position.

5. as the power transmission position in each described core complex in the claim 1 to 4, it is characterized in that described force transfer element (7 and 12) has one or more ring flanges (9 and 14).

6. as the power transmission position in each described core complex in the claim 1 to 5, it is characterized in that described force transfer element has the hole (8 and 13) that is used to hold fastening element (4) and is connected with the core complex structure on the thickness direction of core complex structure by fastening element in the power transmission band of position.

7. as the power transmission position in each described core complex in the claim 1 to 6, it is characterized in that described force transfer element (7) is arranged on the cover layer in two cover layers (1 or 3), perhaps is arranged on two cover layers (1 and 3).

8. as the power transmission position in each described core complex in the claim 1 to 7, it is characterized in that described force transfer element (12) is arranged on a tectal inside of two cover layers (1 or 3), perhaps be arranged on the inside of two cover layers (1 and 3).

9. as the power transmission position in each described core complex in the claim 1 to 8, it is characterized in that described force transfer element (12) is arranged between two cover layers (1 and 3) and/or penetrates core material (2).

10. as the power transmission position in each described core complex in the claim 1 to 9, it is characterized in that described force transfer element has and one or morely leans at described cover layer (1 or 3) or lean extension (11 and 16) on described each cover layer (1 and 3).

11. method that is used for making as the power transmission position in each described core complex of claim 1 to 4, it is characterized in that, in the job step before one is in the matrix material that adds polymerization, in the power transmission band of position, remove or compression core material (2), two cover layers of amalgamation (1 and 3), and with upper caldding layer (1), core material (2) and lower caldding layer (3) are in the power transmission band of position and/or exceed (6) beyond this power transmission position and sew up mutually on the thickness direction of core complex structure by means of the fastening element (4) of the weaving that adds by a kind of stitching process.

12. method that is used for making as the power transmission position in each described core complex of claim 1 to 11, it is characterized in that, in the job step before one is in the matrix material that adds polymerization, in the power transmission band of position, force transfer element (7 and 12) and core complex structure are sewed up on the thickness direction of core complex structure mutually by means of the fastening element (4) of the weaving that adds by a kind of stitching process in the power transmission zone.

13. method that is used for making as the power transmission position in each described core complex of claim 1 to 10, it is characterized in that, in the job step before one is in the matrix material that adds polymerization, in the power transmission band of position, upper caldding layer (1), sandwich layer (2) and lower caldding layer (3) are sewed up on the thickness direction of core complex structure by means of the fastening element (4) of the weaving that adds by a kind of stitching process in addition mutually in the force transfer element zone.

14. use and be used to construct spacecraft, aircraft, marine equipment or land conveying tools as each described power transmission position in the claim 1 to 10.

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