EP2063214A1

EP2063214A1 - Ballistic protective device

Info

Publication number: EP2063214A1
Application number: EP20080169725
Authority: EP
Inventors: Benoît Clement; Karine Thoral-Pierre
Original assignee: TDA Armements SAS
Current assignee: TDA Armements SAS
Priority date: 2007-11-23
Filing date: 2008-11-21
Publication date: 2009-05-27
Also published as: FR2924210A1; US20090155523A1; EP2063214B1; US7846854B2; FR2924210B1

Abstract

The device has three synthetic fabric layers (31-33) forming reinforcements of a single piece obtained by transfer molding of phenolic resin, where the device is constituted by 30 percentages of the resin and 70 percentages of fabrics. The layer (32) includes a fabric with glass fibers crossed with carbon fibers. The fabric of the layer (33) includes a mesh that is fine than that of the layers (31, 32), where each layer includes a stack of fabric layers. The layer (33) includes thickness that is half of thickness of the layer (32).

Description

The present invention relates to a ballistic device. It applies for example to protect vehicles or persons against ballistic type of aggression.
ballistic protection devices fitted to various types of structures, equipment or people. For example, light vehicles likely to move in hostile territory, eg reconnaissance mission, are equipped with ballistic protection.
The primary purpose of these devices is to effectively protect against ballistic attacks, including piercing projectiles. For this purpose, they have in particular one or more layers of steels generally associated with ceramic layers, all said layers being secured together by glue joints or by screwed studs. These assemblies thus form panels shields can withstand piercing projectiles of varying size and very high kinetic energy.
These panels have several disadvantages. A first drawback is their weight and their low maneuverability. In particular the materials of these panels and their required thicknesses give the whole a lot of weight coupled with a lack of flexibility.
A second disadvantage is the lack of adjustment of these devices forms more or less complex. The protective panels used can marry all sorts of shapes. For practical reasons, the dimensions of panels can not go below a certain surface, which limits the possible forms, especially the rounded shapes are excluded.
Another disadvantage is especially the corners, or edges, protruding that can present these shapes composed of flat panels. In particular, these angles or protruding edges are easily spotted by radar systems.
An object of the invention is notably to alleviate the aforementioned drawbacks. To this end, the invention relates to a protection device against ballistic projectiles, comprising at least three layers of synthetic fabrics forming the reinforcements of one piece obtained by resin transfer molding.
In the first layer, the fabric is for example composed of fibers woven in two dimensions, the warp and the weft forming between them an angle less than or equal to 90 °.
In a particular embodiment, the first layer, oriented towards the projectiles, is composed of fabric of aramide fibers.
the middle layer is made of fabric comprising fibers cross glasses with carbon fibers.
The middle layer is, for example woven in three dimensions, the glass fibers and the carbon fibers being woven in two dimensions, the fibers of glasses being oriented in a first direction and the carbon fibers being oriented in a second direction.
The two directions may cross at an angle less than or equal to 90 °, for example between 30 ° and 60 °.
These woven reinforcements, stacked in pairs, are linked together to ensure cohesion in the third direction.
The third layer consists, for example of fabric reinforcements linked in pairs by the weaving process in the third direction.
A set of two woven reinforcements linked in pairs comprises a first carbon fiber reinforcement related to the second aramid fiber.
The fabric of the third layer comprises, for example a finer mesh than that of other layers.
Each layer comprises a stack of fabric layers, the number of fabric layers depending on the desired thickness.
In a particular embodiment, the thickness of the third layer is half the thickness of the middle layer.
Advantageously, the resin may be a phenolic resin.
The proportion of resin is for example 30% and the proportion of fabrics is 70%.
Other features and advantages of the invention will appear with the following description made with reference to the accompanying drawings which show:

the 1a and 1b , Examples of ballistic protective panel according to the prior art;
the Figure 2 , An example of assembly of panels of the type of figure 1 to form a protective structure;
the Figure 3 An example of a possible embodiment of a protection device according to the invention;
the 4a and 4b An illustration of the principle of construction of a two-dimensional weaving;
the 5a , 5b and 5c An illustration of the principles of making a three-dimensional weaving;
the Figure 6 , A possible example of weaving to form a final layer of a device according to the invention;
the Figure 7 , An illustration of a method for producing a device according to the invention.

The 1a and 1b show an example of ballistic protective panel 1 according to the prior art. This panel comprises several layers 11, 12, 13 juxtaposed fixed together by contiguous layers of glue 10 or threaded bolts 14. The outer layer is for example a ceramic type material while the core layer 12 is steel, layer 13 of composite material type. Depending on the thickness, including the core layer 12, the panel is more or less heavy. In all cases of application, its weight is an obstacle.
The layers 11, 12 can also at the impact of a ballistic projectile rear produce effects such as shrapnel. These effects are usually harmful or dangerous to the environment, particularly for people.
The Figure 2 shows a panel assembly 1 of the type of figure 1 for application of a material 21. The assembly wife realized as much as possible the shape of the material 21, but not optimally.
The two panels are interconnected at their edges to form a projecting angle 22 due to the adopted contour. This angle may facilitate detection of the assembly by radar systems, in particular by increasing the radar cross.
The Figure 3 shows an example of possible embodiment of a protection device according to the invention. The device is shown in partial sectional view. The part shown is flat but it may advantageously take all sorts of forms. The panel of Figure 3 is formed of a one-piece composite material comprising three layers 31, 32, 33 integral made from the same mold.
The first layer 31 is disposed on the side of the threat, namely the arrival of a ballistic projectile 30. It is for example made of aramid fibers embedded in the resin. The fibers are previously woven dry in a weaving in two dimensions. The dry fabric forms the reinforcing layer 31 more tissue layers being necessary to obtain the desired thickness of the layer 31 obtained by transfer molding resin, as will be described later.
The 4a and 4b illustrate the principle embodiment of a weaving two-dimensional, respectively a sectional view and a top view. Conventionally, the mesh intersect at the two dimensions, that is to say in a plane, forming a regular reinforcement. The 4b shows an example where the son of the weft and warp intersect perpendicularly. It is possible to provide a weaving where son cross at an angle different from 90 °, for example at an angle between 30 ° and 60 °.
The first layer 31 has for example a thickness of the order of 1 to 1.5 millimeters. The number of bunk reinforcements to obtain the desired thickness can be determined a priori.
This first gauge layer to a minimum diameter of penetration, it decreases the depth of penetration. It also prevents the aforementioned rear effects.
The second layer 32 comprises glass fibers and carbon fibers fixed in the matrix. These fibers are previously dry woven according to a weave in three dimensions for example. This dry fabric forms the reinforcing layer 32.
The 5a 5b and 5c illustrate the principle embodiment of a weaving in three dimensions. This weaving includes a first reinforcing fibers 51 and 51 'along a plane weaving, in two dimensions, the type of 4a and 4b . In the case of the second layer 32, this reinforcement is for example made of glass fibers 51 in a direction and carbon fibers 51 'in the other direction. As for the weaving of the first layer, these two directions may be oriented at an angle less than or equal to 90 °, for example between 30 ° and 90 °.
In this first reinforcement overlaps a second reinforcement identical to the first, positioned in mirror symmetry relative to the first.
The cohesion of the two reinforcements in the third direction is done either by sewing with son 52, or by an adhesive film 53. This second layer has a major role since it breaks the projectile or blocks and dissipates energy due to shock. The size of the weaving mesh is particularly adapted to the diameter of the projectiles. Regarding the thickness, it is also appropriate to the projectile and in particular its penetrating power. A thickness of the order of 50 to 80 millimeters may be required. Necessary woven reinforcements are stacked in sufficient numbers to obtain the desired thickness.
The third layer 33 is for example composed of two woven reinforcements linked in pairs in the weaving process, these reinforcements being then juxtaposed to obtain the desired thickness. A first reinforcement comprises a first layer, such as carbon fiber or fiberglass, bonded to a second web by passing a weft or warp of the first sheet in the second, for example aramid fiber in the case of this layer 33.
The Figure 6 illustrates a possible type of link between the two reinforcements. A first reinforcement 61 is seen from above. frame of the son or chain 62 of the other reinforcement, situated below, of cross meshes of this first reinforcement 61 for securing together the two reinforcements. Weaving reinforcements is for example made in a fine mesh.
In particular, this third layer 33 is collecting the residual deformation of the second layer 32, dissipates the shock wave. It brings particular strength with the continuity of matter, by dissipating mechanical stress across the back.
The third layer 33 has for example a thickness of the order of half the thickness of the second layer 32.
The thicknesses of the layers are adapted to the level of protection sought.
protective layers 34, 35 are for example fixed on each side of the assembly formed of the three layers 31, 32, 33. A conductive film or a suitable paint may be applied on these layers.
The Figure 7 illustrates a known method of making a composite material part obtained by resin transfer molding. According to the invention, the three layers 31, 32, 33 are molded with resin, in a single piece to form a unitary composite material. More particularly, all the layers are wet at the same time by the resin. They are not stuck together.
The set of three layers is formed of superposed webs 71, 72, 73. Each layer is characterized by its tissue type. The number of layers of fabric of each layer 31, 32, 33 depends on the level or the type of protection being sought as described above. These layers are stacked at the bottom of a mold 70, shown in section, whose inner shape corresponds to the shape that it is desired to give to the protective device. A large number of shapes is possible.
The top of the mold is closed by a cover 74, in fact a semi-permeable plastic sheeting. 75 arranged joints between the sheet and the mold used to seal and so close the mold well.
In a first phase, dry tissue collections 71, 72, 73 are thus stacked in the mold, then the latter is closed by the sheet 74. Then, a vacuum pump 77 is activated. The latter is connected by a conduit 78 inside the mold. This conduit 78 opens at a location at the tissue layers substantially opposite to that opens arrival 76 resin. In the next phase, by operating the stop valve 79, the liquid resin is fed to the mold by a suitable conduit 76 placed so that the resin penetrates all layers. A gate located at the conduit 78 of the vacuum pump stops the flow of the resin.
Advantageously, tissue spot thicknesses can be achieved in some places to make reinforcements or contain inserts.
The resin used may be epoxy resin or phenolic resin. This resin has notably the advantage of being a very good thermal insulator, which improves the fire resistance.
In the overall weight balance of a device according to the invention, the proportion of resin forming the matrix may be for example of the order of 30% and the proportion of fabrics may be of the order of 70% . This structure provides a significant weight gain while maintaining excellent mechanical strength as demonstrated by tests conducted by the Applicant.

Claims

A protection device against ballistic projectiles, characterized in that it comprises at least three layers (31, 32, 33) of synthetic fabrics forming the reinforcements of one piece obtained by transfer molding resin, the middle layer ( 32) comprising a fabric comprising glass fibers crossed with carbon fibers.
Device according to Claim 1, characterized in that the middle layer (32) is woven in a three-dimensional reinforcement, the glass fibers (51) and the carbon fibers (51 ') being woven in a two-dimensional reinforcement the glass fibers being oriented in a first direction and the carbon fibers being oriented in a second direction, the cohesion in the third direction being provided by a bond (52) between these reinforcements arranged in pairs in mirror symmetry.
Device according to Claim 2, characterized in that the two directions cross at an angle less than 90 °.
Device according to claim 3, characterized in that the two directions cross at an angle between 30 ° and 60 °.
Device according to any one of claims 2 to 4, characterized in that the second frame (52) is composed of carbon fibers or glass fibers.
Device according to any one of claims 2 to 4, characterized in that the connection (52) operated by a bonding process.
Device according to any one of the preceding claims, characterized in that the first layer (31), oriented towards the projectiles, the fabric consists of aramid fibers.
Device according to any one of the preceding claims, characterized in that the first layer (31), oriented towards the projectiles, the fabric consists of fibers woven in two dimensions, in two directions forming between them an angle less than or equal to 90 °.
Device according to Claim 8, characterized in that the angle is between 30 ° and 60 °.
Device according to any one of the preceding claims, characterized in that the third layer (33) consists of fabric reinforcements (61, 62) linked in pairs.
Device according to Claim 10, characterized in that a set of two reinforcements (61, 62) linked in pairs comprises a first reinforcement of carbon or glass fibers linked to a second reinforcement of aramid fibers.
Device according to any one of the preceding claims, characterized in that the fabric of the third layer (33) has a thinner than other layers of mesh (31, 32).
Device according to any one of the preceding claims, characterized in that each layer (31, 32, 33) comprises a stack of fabric layers (71, 72, 73), the number of fabric layers depending on the desired thickness and stopping power of projectiles.
Device according to any one of the preceding claims, characterized in that the thickness of the third layer (33) is half the thickness of the middle layer (32).
Device according to any one of the preceding claims, characterized in that the resin is a phenolic resin.
Device according to any one of the preceding claims, characterized in that the proportion of resin is 30% and the proportion of fabrics is 70%.