Abstract
The invention is directed to a load application element (1) which comprises at least one reinforcing element (3) that comprises a layered setup from several layers of a composite material. The reinforcing element (3) is at least partially encompassed by an outer housing (2).
Claims
1. A load application element comprising: a. at least one reinforcing element comprising a layered setup from several layers of a composite material; and b. an outer housing which encompasses the reinforcing element at least partially.
2. The load application element according to claim 1, wherein a loading means is mechanically interconnected to and/or incorporated in the at least one reinforcing element.
3. The load application element according to claim 2, wherein the loading means is a thread or a bushing arranged at least partially in the reinforcing element.
4. The load application element according to claim 2, wherein the loading means is made from a metal or a ceramic or plastic, or a fiber reinforced plastic.
5. The load application element according to claim 1, wherein the outer housing comprises at least one fastening means to fasten the load application element to an external structure.
6. The load application element according to claim 1, wherein the reinforcing element comprises at least one fastening means to fasten the load application element to an external structure.
7. The load application element according to claim 1, wherein the load application element is embedded in a wall of a structure made at least partially from a composite material.
8. The load application element according to claim 1, wherein the reinforcing element has a rectangular, circular, pyramidal, oval, or star-like shape.
9. The load application element according to claim 1, wherein the outer housing comprises ribs.
10. The load application element according to claim 1, wherein the outer housing is made from an injection and/or compression and/or thermoformed plastic material.
11. The load application element according to claim 1, wherein in a section view the outer housing encompasses the reinforcing element on at least two sides.
12. The load application element according to claim 1, wherein the housing is made from a plastic material comprising short fibers.
13. The load application element according to claim 1, wherein the at least one reinforcing element comprises a fiber reinforced plastic which comprises long fibers.
14. The load application element according to claim 1, wherein the at least one reinforcing element comprises carbon fibers and/or glass fibers, and/or aramide fibers, and/or basalt fibers.
15. The load application element according to claim 1, wherein the at least one reinforcing element comprises multiple layers of a textile semi-finished product.
16. The load application element according to claim 15, wherein the multiple layers are stitch-bonded or sewn together.
17. A method for producing a load application element according to claim 1, comprising the steps of: a. providing an outer housing; b. inserting a dry textile semi-finished product into the outer housing; and c. impregnating the dry textile semi-finished product by resin injection.
18. The method for producing a load application element according to claim 17, wherein the dry textile semi-finished product comprises at least one opening which is used to position the textile semi-finished product in the forming tool.
19. The method for producing a load application element according to claim 18, wherein the at least one opening is provided with a thread.
20. A method for producing a load application element according to claim 1, comprising the steps of: a. inserting a reinforcing element made from an at least partially cured fiber reinforced plastic material into a forming tool; b. closing the forming tool; and c. injecting material into the forming tool to form an outer housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings, which should not be considered as limiting to the invention described in the appended claims.
[0045] FIG. 1 schematically shows a an embodiment of a load application element in a perspective view;
[0046] FIG. 2 schematically shows the load application element of FIG. 1 in a frontal view;
[0047] FIG. 3 shows cross-section A-A of FIG. 2;
[0048] FIG. 4 shows a cross-section similar to cross-section A-A for another embodiment of a load application element;
[0049] FIG. 5 shows a cross-section similar to cross-section A-A for another embodiment of a load application element;
[0050] FIG. 6 shows a cross-section similar to cross-section A-A for another embodiment of a load application element;
[0051] FIG. 7 shows a cross-section similar to cross-section A-A for another embodiment of a load application element;
[0052] FIG. 8 shows an embodiment of a load application element with a portion of it being clipped for illustrative purposes, in a perspective view;
[0053] FIG. 9 shows an embodiment of a textile semi-finished product which may be used as a reinforcing element;
[0054] FIG. 10 shows an embodiment of a load application element with a portion of it being clipped for illustrative purposes in a perspective view;
[0055] FIG. 11 shows the load application element of FIG. 9 mounted in a composite structure;
[0056] FIG. 12 shows an embodiment of a load application element which is fastened to a composite structure by means of connecting members;
[0057] FIG. 13 shows an embodiment of a load application element;
[0058] FIG. 14 shows an embodiment of a load application element;
[0059] FIG. 15 shows an embodiment of a load application element.
DETAILED DESCRIPTION OF THE INVENTION
[0060] The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, an embodiment that is presently preferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed.
[0061] FIGS. 1 and 2 show an embodiment of a load application element 1 in a perspective view. The load application element 1 comprises an outer housing 1 which is made from a short-fibers reinforced plastic. The outer housing 2 comprises multiple fastening means 7 which may be used in order to mechanically interconnect the load application element 1 with a structure (not shown), as will be explained in FIG. 12. Such fastening means 7 may be used in order to position and preliminarily fix a load application element 1 to a composite structure (not shown) during the production of such a structure. Hence a proper positioning of the force introduction points of such a structure can be ensured. In addition, the embodiment of a load application element 1 shown in FIGS. 1 and 2 comprises an attachment face which has a shape (geometry) that aligns with a structure it has to be connected to. Hence the load application element 1 may e.g. be interconnected with such a structure by an adhesive film (not shown).
[0062] FIG. 3 shows cross-section A-A of FIG. 2. As illustrated, the embodiment of a load application element 1 shown comprises an inner reinforcing element 3 which is made from a long-fibers reinforced plastic. The reinforcing element 3 comprises multiple layers (layup in z-direction) of fibers, whereby the orientation of the fibers varies between the different layers. Within the reinforcing element 3, a loading means 4 is embedded, which in the embodiment shown is a threaded bushing.
[0063] FIG. 4 shows a cross-section of another embodiment of a load application element 1. In contrast to the embodiment shown in FIG. 3, the load application element 1 shown in FIG. 4 comprises a loading means which is also partially embedded in the outer housing 2, what may add additional pull-out strength to the loading means.
[0064] As shown in FIG. 5, a loading means 4 may on its surface also comprise a protrusion, such as teeth, or another type of locking means in order to improve its anchorage in the reinforcing element 3 by form-locking.
[0065] FIG. 6 illustrates another embodiment of a load application element 1 with an outer housing 2 that has a slightly different shape. Within the outer housing 2, a loading means 4 is embedded in a central reinforcing element 3 which itself is partially embedded in peripheral reinforcing element 6. Hence, in such an embodiment, load transmission, respectively force distribution may be controlled more efficiently.
[0066] FIG. 7 shows another embodiment of a load application element 1 where the loading means 4 is a helical insert. Such types of loading means 4 can e.g. be used in order to obtain particularly lightweight load application elements 1, as thus the amount of relatively heavy metal components can be kept to a minimum. Thus, depending on the application, helical inserts may be made from steel alloys which are electrochemically compatible with e.g. carbon fibers and hence can be used in combination with reinforcing elements 3 comprising carbon fibers.
[0067] FIG. 8 shows another embodiment of a load application element 1 whereof a part has been clipped in order to illustrate its inner structure. In this embodiment of the invention, the loading means 4 significantly protrudes from the outer housing 2. The loading means 4 also comprises protrusions 5 which improve its anchorage in the reinforcing element 3. Such an embodiment of a load application element 1 may e.g. be used in order to establish a pin joint to an external structure (not shown).
[0068] FIG. 9 shows a variation of textile semi-finished product 9 which may be used in order to produce a reinforcing element 3 for a load application element 1 according to the present invention. This type of textile semi-finished product 9 comprises multiple plies (layers) 10 of textiles that comprise reinforcing fibers (not shown in detail). The plies 10 are stitch-bonded by multiple stitches 11. Thus misalignment of the plies of the textile semi-finished product 9 during the production process of a load application element can be prevented.
[0069] FIGS. 10 and 11 show another embodiment of a load application element 1, whose shape/geometry as well as mechanical properties are adapted to a composite structure 12. The load application element 1 has an oval cross section which varies in z-direction. When mounted, the load application element is partially embedded in the composite structure, as can be seen in FIG. 11.
[0070] FIG. 12 shows another embodiment of load application element 1 which is mounted on the surface of a composite structure 12. The force introduction element and the composite structure are connected by means of connecting members 13 which are screws positioned in the fastening means. The loading means 4 is a thread which is directly cut in the reinforcing element 3. Hence the loading means 4 is made from the same material as the reinforcing element 3, respectively is integrally formed with the reinforcing element 3.
[0071] FIG. 13 shows an embodiment of a load application element 1 which can be engaged through a bore in the composite structure 21.
[0072] FIGS. 14 and 15 show two other embodiments load application elements 1 according to the invention with different geometries. The load application element 1 shown in FIG. 14 is essentially star-shaped and comprises two loading means 4. Such embodiments may e.g. be advantageous in order to distribute applied loads over a larger area, taking anisotropy of an adjacent composite structure into account. The load application element 1 shown in FIG. 15 has an essentially cylindrical shape and only one loading means 4.
NUMBERS
[0073] 1 Load application element [0074] 2 Housing [0075] 3 Reinforcing element [0076] 4 Loading means [0077] 5 Protrusions [0078] 6 Peripheral reinforcing element [0079] 7 Fastening means [0080] 8 Attachment face [0081] 9 Textile semi-finished product [0082] 10 Ply [0083] 11 Stitch [0084] 12 Composite structure [0085] 13 Connecting member
