Structural component for armored vehicles

Abstract

Armor plating is provided for armored land vehicles or watercraft, the armor having a base armor plate and an additional armor plate fixed thereto on the enemy side, such that it can be removed. A structural component can be used as a base armor plate for such vehicles, and comprises a layered structure with a core composite having an inner honeycomb core and at least one covering layer. The layered structure does not contain supporting metal layers or ceramic, hard material layers. Another essential characteristic is the use of fixture elements which are anchored in the core composite to allow additional armor plating to be detachably fixed on the enemy side. The core composite therefore essentially offers basic protection itself, while also acting as the carrier structure for interchangeable additional armor plating.

Claims

1. A structural component for an armored vehicle, the component comprising: an additional armor plating providing ballistic protection, the additional armor plating being removably fixed at an enemy side and exerting a load on the structural component; a layer structure having a core composite including an inner honeycomb core and at least one cover layer, the layer structure including neither a supporting metal layer nor a ballistic impact layer of ceramic; at least three fixing regions, each fixing region comprising a corresponding respective locally delimited surface area that comprises a blind hole and that is located within the honeycomb core of the core composite, each fixing region containing at least one fixing element that is at least partially inserted into the blind hole and that cooperates with the additional armor plating for releasable fixing of the additional armor plating on the enemy side each fixing element having a form of a flange bush comprising a flange bearing against the at least one cover layer at the enemy side, such that substantially the core composite itself affords basic protection and the core composite represents a supporting structure for interchangeable additional armor plating; and at least one reinforced region for connecting the structural component to a remaining structure of the armored vehicle, wherein all cells of the honeycomb core within the respective locally delimited surface area of each of the at least three fixing regions are completely filled with a filling material such that, in each of the at least three fixing regions, the fixing element is anchored in the respective blind hole and to the filling material surrounding the respective blind hole.

2. The structural component as set forth in claim 1, wherein a mean weight in relation to a surface area of the core composite is less than 40 kg/m.sup.2, optionally less than 15 kg/m.sup.2.

3. The structural component as set forth in claim 1, wherein the core composite comprises the honeycomb core and two mutually opposite cover layers and together with a fragmentation protection layer at a friendly side represents the basic protection.

4. The structural component as set forth in claim 3, wherein the structural component comprising the layer structure comprising the following layers: one of the two mutually opposite cover layers at the enemy side; the honeycomb core, optionally of fiber-reinforced plastic; another one of the two mutually opposite cover layers at the friendly side; the fragmentation protection layer at the friendly side, optionally high-strength polyethylene, which is fixed directly on the cover layer at the friendly side, and optionally adhesive layers between the layers.

5. The structural component as set forth in claim 1, wherein the honeycomb core has a mean wall thickness (d1) in a range of between 3 mm and 75 mm, optionally in a range of between 5 mm and 50 mm.

6. The structural component as set forth in claim 5, wherein the cover layer at a friendly side and/or the cover layer at the enemy side has a mean wall thickness (d3) in a range of between 0.2 mm and 15 mm, optionally in a range of between 0.3 mm and 10 mm.

7. The structural component as set forth in claim 1, wherein the fixing elements include fixing bushes which are respectively anchored in the at least three fixing regions within the honeycomb core of the core composite by an adhesive.

8. The structural component as set forth in claim 1, further comprising a plurality of reinforced regions distributed over at least part of or an entire periphery of the outer edge region of the core composite for connecting the structural component to the remaining structure of the vehicle.

9. The structural component as set forth in claim 1, wherein the honeycomb core has hollow cells in honeycomb form, optionally produced using an expansion process.

10. The structural component as set forth in claim 1, having a form of a door.

11. The structural component as set forth in claim 10, wherein a lower portion and upper portion of the door are angled relative to each other and are connected by a flexing region.

12. The structural component as set forth in claim 11, wherein the flexing region of the honeycomb core runs seamlessly from the lower portion to the upper portion.

13. Armor of an armored vehicle, the armor comprising a base armor plating and an additional armor plating is removably fixed thereto at an enemy side, optionally with an air gap, wherein the base armor plating has at least one structural component as set forth in claim 1.

14. An armored military land vehicle or water craft having a door in a form of a structural component as set forth in claim 1.

15. The structural component as set forth in claim 1, wherein the filling material is a hardenable thermoset.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The invention is described in greater detail hereinafter, without limitation on the scope of protection, by the description of a preferred embodiment with reference to the accompanying drawings in which:

(2) FIG. 1 shows a front view of a structural component designed according to an embodiment of the invention for use as a door of an armored vehicle or craft;

(3) FIG. 2 shows a longitudinal section vertically through the structural component of FIG. 1;

(4) FIG. 3 shows an enlarged portion of the longitudinal section in FIG. 2 corresponding to region III; and

(5) FIG. 4 shows an enlarged partial section along line IV-IV in FIG. 1.

(6) Identical references denote identical components in all Figures.

DETAILED DESCRIPTION OF THE INVENTION

(7) In FIGS. 1 through 4 a structural component designed for use as a door is generally identified by 10. The structural component 10 is intended for use in an armored land vehicle, for example a military armored personnel carrier, an armored infantry fighting vehicle, an armored reconnaissance vehicle, or a combat tank.

(8) By way of introduction it is to be noted that FIGS. 1 through 4 do not show the per se known construction of suitable additional armor platings. Such an additional armor plating (add-on) is, however, always mounted at the enemy side on the structural component 10 in the operationally readiness condition of the vehicle, for most effectors or projectiles are nowadays capable of penetrating common basic protection, including for example the structural component 10. Therefore generally modules which are adapted to the respective mission of an additional armor plating are mechanically removably fixed in the form of so-called add-on protection to a structural component 10 according to the invention in order to increase the protection level and in particular to minimize the risk of penetration of different effectors.

(9) Such additional armor platings which are not shown in greater detail produce the main contribution to the desired multi-hit capacity, for resistance against improvised explosive devices (IEDs) and so-called explosive formed projectile IEDs (EFP-IEDs) which are increasingly occurring. A decisive basic protection function at least in relation to shock waves and fragmentation splinters is however also achieved by the structure (described hereinafter) of a structural component 10 as shown in FIGS. 1 through 4.

(10) Governed by the use involved, the structural component 10 is first of a contour with a flat structure, that is suitable for the intended use, here as a door. The structural component 10 shown in FIGS. 1 through 4 is of a two-part construction with an upper portion 12 and a lower portion 14 which are angled from each other by a flexing region 16, with a suitable angle for example of about 10-30o. The angling configuration by virtue of the flexing region 16 reduces the probability of a highly detrimental perpendicular strike of effectors as at least a partial region of the structural component 10, for example the upper portion 12, can be disposed inclined relative to the vertical after being fitted to the vehicle. An opening 17 can be provided, for example for an armored glass window, in the upper portion 12. For fixing the structural component 10 to a frame of the vehicle, there are provided bores 18 distributed over the periphery, through the structural component 10. The opening 17 is equally bordered by regularly distributed bores 19 for fixing of the armored glass panel.

(11) As can best be seen from FIGS. 3-4, the structural component 10 is of a comparatively simple layer structure 20. The layer structure 20 is only made from two substantial constituent parts, namely a core composite 22 and a fragmentation protection layer 24 at the rear or friend side. The fragmentation protection layer 24 is made for example from a continuous plate-like layer of monolithic high-strength PE of per se known kind, for example Dyneema from Koninklijke DSM N.V., Heerlen, Netherlands. Other materials suitable as the fragmentation protection can also be used, for example Kevlar (from DuPont, Wilmington, USA). The fragmentation protection layer 24 is materially bonded as shown in FIGS. 1-4 by adhesive to the inwardly disposed cover layer 26 of the core composite 24, but it could also be fixed in another fashion, for example by riveting.

(12) The core composite 22 which is essential to the invention in turn substantially only comprises three layers, namely the honeycomb core 25 which extensive in terms of surface area and cover layers 26 on both sides thereof. In this case the honeycomb core 25 is of a known structure with hollow cells in hexagonal cross-sectional form or honeycomb form. The honeycomb core 25 is produced in per se known manner for example using an expansion process. The cell walls in the honeycomb core 25 are directed in the core composite 22 perpendicularly to its areal direction of extension, that is to say horizontally in FIG. 4. Suitable processes for the production of composite panels or the core composite 22 are known to the man skilled in the art.

(13) Both the honeycomb core 25 and also the cover layers 26 are preferably each made from FCP, wherein different material combinations are considered. Highly modular fiber materials like for example glass fiber honeycomb, KEVLAR, NOMEX or other aramide fibers, carbon fibers, or also metal or mineral fibers which impregnated with suitable synthetic resin are hardened to give a highly modular FCP can be recommended for production of the honeycomb core 25. Unimpregnated honeycomb cores 25 of metal film, in particular aluminum film, are also basically suitable. The thickness or wall thickness d1 of the honeycomb core 25 depends in particular on the weight of the add-on protection to be fitted, wherein d1 should be in the region of between 0.5 cm and 5 cm.

(14) Single-layer or multi-layer composite materials or also monolithic layers can be used in the core composite 22 as cover layers 26 of the honeycomb core 25. In particular lightweight materials like GRP, CRP, aluminum film or also monolithic aramides or other polymers like high-strength PE are considered. The thickness or wall thickness of the cover layers 26, denoted by d3 in FIG. 3, can typically be between 0.3 mm and 10 mm depending on the respectively required weight of the basic protection structure, and do not have to be identical on both sides. Besides the load-carrying capacity of the core composite 24, further basic protection functionalities, for example including in relation to fragmentation splinters, can also be adjusted by way of the material and thickness of the cover layers 26. The cover layers 26 are materially bonded to the honeycomb core 25 by adhesive. The adhesive adopted is an adhesive join which is suitable in accordance with the material pairings of cover layers 26 and honeycomb core 25. In the case of cover layers 26 and honeycomb core 25 of GRP a good adhesive bond can be effected by hardening a thin intermediate layer (not shown) of a suitable thermoplastic material. Finally, in regard to production of the core composite 22, it is also to be noted that the angle between the lower portion 12 and the upper portion 14, that is to say the curvature in the flexing region 16, is preferably already implemented by plastic deformation and without cutting machining prior to hardening of the FCP cover layers 26 and the adhesive join thereof to the honeycomb core 25. Accordingly in the flexing region 16 in the preferred configuration the honeycomb core 25 is seamlessly continuous or is formed in one piece without a join, in particular without an assembly of two separate honeycomb portions.

(15) In FIG. 3 reference d2 also denotes the wall thickness of the fragmentation protection layer 24. That wall thickness d2 in contrast depends substantially purely on the function of the fragmentation protection layer 24 and should preferably be in the region of between 1 cm and 5 cm. Tests (see below) have shown that in particular high-strength polyethylene (PE) is capable of coherently defending against an EFD-IED, that is to say with buckling but without cracking or tearing of the fragmentation protection layer 24. The necessary thickness of a fragmentation protection layer 24 can however vary according to the respective application.

(16) A plurality of fixing elements 30 are provided in the structural component 10 on the enemy side for removably fixing an additional armor plating linked to use involved. As shown in FIG. 1, in the case of symmetrical components, the fixing elements 30 are desirably distributed approximately equally and symmetrically over the area. That achieves a more uniform load distribution, both in regard to weight of the additional armor plating and also and in particular in regard to strike impact forces. To simplify the view, FIG. 1 does not show any fixing elements in the upper portion 14, but they can also be provided there. Preferably, one fixing element 30 is provided approximately per 0.2 m.sup.2-0.5 m.sup.2.

(17) The structure and function of the fixing elements 30 can be seen in greater detail from FIG. 4. Each fixing element is in the form of a flange bush 30, for example of suitable steel or light metal. The fixing elements 30 can alternatively be made from high-strength plastic. In the illustrated example the flange bush 30 has a female thread 32 into which a suitable pin (not shown) is screwed, as a further part of the fixing elements. An additional armor plating is in turn releasably fixed to that pin, wherein the pin is used as a spacer for producing an air gap between the structural component 10 and the additional armor plating. An air gap is typically used, inter alia as that renders certain effectors substantially ineffective against the armor. It will be noted however that the additional armor plating can also be removably screwed on by means of the flange bushes 30 in such a way as to bear directly against the structural component 10. To increase the load-bearing capability the flange bushes 30 have at their end a flange 34 which is integrally formed thereon. The flange 34 bears in a disc shape against the surface at the enemy side, of the outer cover layer 26. The flange socket 30 is additionally supported by the flange 34 to achieve improved force transmission to the core composite 22 which is optimized in respect of pressure loading.

(18) As can further be seen from FIG. 4, a respective locally delimited fixing region 40 is also provided for the transmission of force from the fixing element 30 into the core composite 22. To produce the fixing regions 40 a filling material 42 is already introduced into the cells of the honeycomb core 25 prior to production of the core composite 22. The filling material 42 is introduced in such a way that all cells within the respectively desired surface regions are completely filled up. A hardenable thermoset is particularly preferably used as the filling material 42. It is however also possible to use metal, plastic or fiber composite filling materials or other filling material 42 which is usually employed for so-called potting. It is only after the filling material 42 is introduced that the cover layers 26 are applied so that the cover layers, like also the honeycomb core, are bondingly connected to the filling material 42. That provides overall for a high resistance force against pressure and tension in each fixing region 40, such force still exceeding that of the rest of the surface of the core composite 22. To minimize weight the smallest possible amount of filling material 42 overall should be used.

(19) The hardened filling material 42 is then bored to produce a blind hole which projects to just before the inner cover layer 26, that is to say at the friend side. Then, as shown in FIG. 4, a respective flange bush 30 is anchored in each fixing region 40 as a fixing element, in the blind hole of the finished core composite 22. Anchoring is effected by suitable adhesive involving bonding between the materials, depending on the pairs of materials respectively used for the filling material 42 and the flange bush 30, in the blind hole of the core composite 22. Flange bushes 30 can however also be anchored in bores passing through the core composite 22. The fragmentation protection layer 24 is at any event not adversely affected by the flange bush 30 or its bore. That provides that the fixing element in the form of the flange bush 30 is also secured in relation to tensile force generated by the weight of the additional armor plating. Also, at least one reinforced region (44), or a plurality of reinforced regions (44) as shown in FIG. 1, are distributed over at least part of or an entire periphery of the outer edge region of the core composite (22) for connecting the structural component (10) to a remaining structure of the vehicle.

(20) Finally, key data relating to specific prototypes and test results achieved therewith are set forth below:

Example 1 (Structure Enemy SideFriend Side)

(21) TABLE-US-00001 Weight in relation to area: about 35.5 kg/m.sup.2 (without spall liner 24) Total wall thickness: d4: 50 mm (+/ 1 mm) Thickness: Material: Cover layer (26) d3: 10 mm GRP solid laminate Honeycomb core (25) d1: 10 mm high-module FCP(*) Cover layer (26) d3: 10 mm GRP solid laminate Spall liner (24) d2: 20 mm PE solid material (Dyneema) (*)from Euro-Composites S.A., Echternach, Luxembourg
Test Results for Example 1:

(22) In a blast impact test initially without additional armor plating dynamic buckling was measured with TNT with steel collars in direct comparison with armor steel of an 8 mm wall thickness. The maximum value (peak) of the dynamic buckling was surprisingly only in the result, that is to say 66% of the dynamic buckling of the comparative test sample of armor steel.

(23) In a further test, to simulate an additional armor plating (add-on) a ceramic plate of about 5 cm wall thickness and while retaining about a 10 cm air gap was fixed to the fixing elements 30 of a structural element 10 as shown in FIGS. 1 through 4, with the dimensioning of Example 1. That structure was bombarded from a distance with an EFP-IED. Protection from ballistic action was admittedly achieved primarily by the additional armor plating, but that was pierced by the EFP-IED projectile. The projectile was contained with buckling but without cracking or tearing in the integrated fragmentation protection layer 24 (spall liner) of the layer structure 20.

Example 2 (Structure Enemy SideFriend Side)

(24) TABLE-US-00002 Weight in relation to area: about 6.71 kg/m.sup.2 (without spall liner 24) Total wall thickness: d4: 40 mm (+/ 1 mm) Thickness: Material: Cover layer (26) d3: 0.9 mm GRP solid laminate Honeycomb core (25) d1: 18.2 mm high-module FCP(*) Cover layer (26) d3: 0.9 mm GRP solid laminate Spall liner (24) d2: 20 mm PE solid material (Dyneema) (*)from Euro-Composites S.A., Echternach, Luxembourg
Test Results for Example 2:

(25) This prototype of Example 2, which in spite of the same total thickness d4 is still lighter, was subjected to a stricter blast impact test with spherical TNT charge in the MIEDAS Test Installation (Meppen Improvised Explosive Device Assessment Structure). To simulate a less impact-resistant additional armor plating an armor steel plate which was only 3 mm in thickness was screwed without an air gap directly on to the structural component 10, with the dimensions of Example 2.

(26) In spite of the wall thickness of the cover layers 26, that is reduced by more than an order of magnitude, and the markedly increased explosive force, buckling without cracking could also be achieved in that test.

(27) It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.