Ballistic armor and its production process

Abstract

Ballistic armor and method of production thereof The present invention relates to ballistic armor (10) comprising a three-dimensional reticular structure (20), which may in particular be regular and / or auxetic, as well as its applications for the protection of personnel and / or equipment (40), and a production method comprising a step of additive manufacturing of at least the three-dimensional reticular structure (20). Figure for abstract: Fig. 5.

Description

Title of the invention: Ballistic armor and its production method Technical field

[0001] The present disclosure relates to armor and in particular ballistic armor intended to protect living beings and / or equipment from the effects of impacts from high-speed projectiles or debris. Prior art

[0002] Typically, ballistic armor, especially that intended for the protection of optronic equipment such as turret-mounted sights or any other equipment, consists of massive and relatively thick plates intended to fragment and slow down projectiles. Although robust and relatively inexpensive, these conventional armors are heavy and rigid, which can involve numerous disadvantages. For example, on a panoramic turret sight, the weight due to the ballistic armor may require the use of more powerful and bulky actuators to actuate the rotation of the turret on each axis, while their rigidity may require additional damping means, such as for example the addition of elastomer elements or polymer foams, in order to limit the transmission to sensitive equipment of forces and vibrations due to impacts.

[0003] In other applications, such as personal protective equipment such as helmets and bulletproof vests, or gas turbine engine casings, the weight and rigidity of massive armor can also cause other disadvantages, such as, for example, hindering the movement of infantrymen wearing such protective equipment.

[0004] Furthermore, as illustrated in [Fig. 1], the deformation of a solid armor 100 following the impact of debris or a projectile 110 can also cause cracks 120 weakening the solid armor 100 against subsequent impacts, or even spalling on the rear face of the armor 100, generating secondary debris 130 which can themselves damage the equipment and / or people that the armor 100 should protect. Statement of the invention

[0005] A first aspect of the present disclosure provides ballistic armor comprising a three-dimensional reticular structure in order to form an architectural material capable of better absorbing the impacts of projectiles or debris while avoiding the propagation of cracks and spalling and with reduced weight. This three-dimensional reticular structure may in particular comprise a unit cell regularly repeated, so as to form a regular structure, but could alternatively be a stochastic structure, with strands and / or thin walls entangled in a substantially random manner.

[0006] In order to better absorb impacts, the three-dimensional reticular structure may be auxetic, i.e. have a negative Poisson's ratio. Thus, compression of the three-dimensional reticular structure in the direction of a ballistic impact would also cause its local contraction perpendicular to the direction of the impact, thus distributing the energy of this impact by traction on the surrounding regions.

[0007] Apart from the three-dimensional reticular structure, the ballistic armor may also comprise one or more panels. Such a panel may, for example, be arranged on an external surface of the ballistic armor, so as to fragment the projectiles or debris before they penetrate the three-dimensional reticular structure. It is also conceivable for the ballistic armor to comprise two opposing panels, between which the three-dimensional reticular structure is interposed, so as to form a light but rigid sandwich structure. However, it is also conceivable, in addition to or as an alternative to panels arranged on one or more external surfaces of the ballistic armor, to arrange at least one panel within the three-dimensional reticular structure, for example interposed between consecutive layers of the three-dimensional reticular structure.

[0008] At least one property of the three-dimensional reticular structure, such as for example the shape and / or size of the unit cell and / or the density, can evolve along at least one axis. This evolution can be staged, so as to form distinct blocks or layers in the three-dimensional reticular structure, but it can also be gradual.

[0009] An empty volume within the three-dimensional reticular structure may be at least partially filled with a different material, in order to combine its properties with those of the three-dimensional reticular structure.

[0010] A second aspect of the present disclosure relates to optronic equipment, such as for example a turret sight, incorporating the ballistic armor according to the first aspect.

[0011] A third aspect of the present disclosure relates to personal protective equipment, such as for example a helmet or a bulletproof vest, incorporating the ballistic armor according to the first aspect.

[0012] A fourth aspect of the present disclosure relates to a method of producing the ballistic armor according to the first aspect, comprising a step of additive manufacturing of at least the three-dimensional reticular structure, for example by fusion powder bed laser, powder bed laser sintering, fused filament deposition, binder jetting, stereolithography, or photocurable resin jetting, so as to easily obtain a complex reticular structure. Brief description of the drawings

[0013] The description refers to the attached drawings in which:

[0014] [Fig-1] [Fig.l] schematically illustrates the effects of a ballistic impact on a massive armor.

[0015] [Fig.2] [Fig.2] schematically illustrates a first embodiment of ballistic armor comprising a three-dimensional reticular structure.

[0016] [Fig.3] [Fig.3] illustrates the reaction of the three-dimensional reticular structure of the first embodiment to a compressive force.

[0017] [Fig.4] [Fig.4] schematically illustrates a second embodiment.

[0018] [Fig.5] [Fig.5] schematically illustrates an application of ballistic armor according to the second embodiment for the protection of optronic equipment.

[0019] [Fig.6] [Fig.6] schematically illustrates a third embodiment.

[0020] [Fig.7] [Fig.7] schematically illustrates an application of ballistic armor according to the third embodiment in personal protective equipment.

[0021] [Fig.8] [Fig.8] schematically illustrates a fourth embodiment.

[0022] [Fig.9] [Fig.9] schematically illustrates a fifth embodiment.

[0023] [Fig. 10] [Fig. 10] schematically illustrates a method of producing ballistic armor according to any of the preceding embodiments. Description of the embodiments

[0024] The invention will be well understood and its advantages will appear better, on reading the detailed description which follows, of embodiments represented by way of non-limiting examples.

[0025] According to a first embodiment, as illustrated in Figures 2 and 3, a ballistic armor 10 may comprise a three-dimensional reticular structure 20, designed so as to form an architectural material, that is to say with a morphology and / or topology giving it improved specific properties. In particular, the morphology and / or topology of this three-dimensional reticular structure 20 may be adapted to better absorb the energy of impacts from debris and / or projectiles, and / or limit the deformation of its rear face, the propagation of cracks and / or spalling in the event of an impact.

[0026] For example, the three-dimensional reticular structure 20 may be configured to make it auxetic, as illustrated in [Fig. 3], showing how a compressive force F, such as may be caused by a projectile impact or high-speed debris, can also cause a contraction of this three-dimensional reticular structure 20 in a direction perpendicular to that of the compression. This lateral contraction can thus make it possible to distribute the force due to the impact laterally over a larger surface area and more efficiently, while limiting the deformation of the rear face of the ballistic armor 10.

[0027] Furthermore, as illustrated in Figures 2 and 3, the three-dimensional reticular structure 20 may be a regular structure, formed by regular repetition of a unit cell 21 formed by an arrangement of strands 22 and / or thin walls in space. It is nevertheless also conceivable that this three-dimensional reticular structure 20 is a stochastic structure, with a random arrangement of the strands and / or walls.

[0028] Although in the embodiment illustrated in Figures 2 and 3 the ballistic armor 10 is formed only by the three-dimensional reticular structure 20, it is also possible to combine such a three-dimensional reticular structure with other elements so as to combine its properties. Thus, in a second embodiment, illustrated in Figures 4 and 5, the ballistic armor 10 may comprise, apart from the three-dimensional reticular structure 20, a solid panel 30 arranged on an external face of the ballistic armor 10 in order to fragment the projectiles and / or debris impacting at high speed, while distributing the force transmitted by the impact over a larger surface area of ​​the three-dimensional reticular structure 20. This panel 30 may be formed in a single piece with the latter, or may be made integral therewith, for example by gluing, welding or mechanical connection by friction or form fit.

[0029] [Fig. 5] further illustrates an application of this ballistic armor 10 for the protection of equipment, and more particularly of optronic equipment 40 in the form of a turret sight. This optronic equipment 40 can therefore comprise a set of sensors 50 mounted on a turret 60 which can have one or more axes of rotation, such as for example a vertical axis Z and a horizontal axis X. The turret 60 can be motorized with actuators (not illustrated) for each axis of rotation Z, X.

[0030] Both the sensor assembly 50 and the actuators of the turret 60 may be vulnerable to impacts, or even vibrations. In order to protect them, the optronic equipment 40 may therefore comprise a casing 70 in one or more parts each incorporating such ballistic armor 10.

[0031] Although in the embodiment illustrated in Figures 4 and 5 a solid panel is incorporated only on the external face of the ballistic armor, it is also possible to incorporate another on the internal face. Thus, in a third embodiment, illustrated in Figures 6 and 7, the ballistic armor 10 may comprise, apart from the three-dimensional reticular structure 20, solid panels 30, 30' arranged respectively on an external face and an internal face of the ballistic armor 10, with the three-dimensional reticular structure 20 interposed between the two, so as to form a sandwich structure. Each of these panels 30 can be formed in a single piece with the three-dimensional reticular structure 20, or can be made integral therewith for example by gluing, welding or mechanical connection by friction or form complementarity. It is thus possible to produce a ballistic armor 10 which is rigid in bending but nevertheless light and offers good impact energy absorption properties. [Fig.7] also illustrates an application of this ballistic armor 10 in personal protective equipment 80, specifically in the form of a helmet.

[0032] It is also conceivable to incorporate one or more solid panels at the heart of the three-dimensional reticular structure, between the internal and external faces of the ballistic armor. Thus, in a fourth embodiment, illustrated in [Fig. 8], the ballistic armor 10 may comprise a first solid panel 30 arranged on an external face of the ballistic armor 10 and a second panel 30' interposed between two layers 20a, 20b of the three-dimensional reticular structure 20. Furthermore, these layers 20a, 20b may have different properties, and in particular different densities, as illustrated in [Fig. 8]. For this, they may in particular be formed by regular repetition of respective different unit cells 21a, 21b.

[0033] Although in the embodiment illustrated in [Fig. 8] the three-dimensional reticular structure has two distinct layers, with a staged evolution of the properties of the three-dimensional reticular structure along the axis, it is however also conceivable to have a gradual evolution of the properties of the three-dimensional reticular structure. Thus, in the ballistic armor 10 according to a fifth embodiment, illustrated in [Fig. 9], the properties of the three-dimensional reticular structure 20, and in particular its density, can evolve gradually without abrupt change. Although in the illustrated examples this evolution is in the direction of the thickness, it is also conceivable to have gradual or abrupt changes in the properties of the three-dimensional reticular structure, to obtain for example different responses to impacts on different areas of the outer surface of the ballistic armor.

[0034] Furthermore, as also illustrated in [Fig. 9], an empty volume inside the three-dimensional reticular structure 20 may be at least partially filled with a different material 22, such as for example a foam, so as to form, with the three-dimensional reticular structure 20, a composite material combining properties of the three-dimensional reticular structure 20 and the material 22. Although that this at least partial filling is only illustrated in this figure, it is also applicable to the previous embodiments.

[0035] Additive manufacturing methods offer increased flexibility for the manufacture of three-dimensional reticular structures. Accordingly, as illustrated in [Fig. 10], a method for producing the ballistic armor 10 according to any of the aforementioned embodiments may comprise a step of additive manufacturing at least the three-dimensional reticular structure 20, for example from a digital model thereof. This digital model may be decomposed into a series of successive slices, and the additive manufacturing of at least the three-dimensional reticular structure proceeds by the selective and computer-controlled deposition and / or consolidation of successive layers of material corresponding to the slices of the digital model.

[0036] Thus, in a step of additive manufacturing by laser sintering on a powder bed, as illustrated in [Fig. 10], layers of powder 90, normally metallic, are successively applied, and between the application of the successive layers, a laser beam 91, directed by a computer 92 on the basis of a digital model, decomposed into successive slices, of at least the three-dimensional reticular structure 20, will selectively melt the powder according to the shape of the corresponding slice of the digital model, so as to selectively consolidate the material of the powder during its cooling and re-solidification and thus manufacture at least this three-dimensional reticular structure 20 according to the digital model. As illustrated in [Fig.10], other elements of the ballistic armor 10, for example one or more solid panels 30, 30', may be manufactured by additive manufacturing together with the three-dimensional reticular structure 20, so as to form a single-piece assembly. It is nevertheless also conceivable to have subsequent finishing and / or assembly steps to obtain the ballistic armor 10 in its final form. Furthermore, although the illustrated method is an additive manufacturing method by laser sintering on a powder bed, other types of additive manufacturing methods, such as for example laser fusion on a powder bed, fused filament deposition, binder jet, stereolithography, or photocurable resin jet, are also conceivable in a similar manner.

[0037] Although the present invention has been described with reference to specific embodiments, it is obvious that various modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the various embodiments discussed may be combined in additional embodiments. For example, the method illustrated in [Fig. 10] is applicable to the manufacture of ballistic armor according to each of the embodiments of the Figures 2 to 9, each of these ballistic armors is capable of being used in the applications illustrated by Figures 5 and 7. Accordingly, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Claims

1. Optronic equipment (40) incorporating ballistic armor (10) comprising a three-dimensional reticular structure (20), wherein at least one property of the three-dimensional reticular structure (20) evolves along at least one axis, and an empty volume within the three-dimensional reticular structure (20) is filled with a different material (22).

2. Optronic equipment (40) according to claim 1, wherein the three-dimensional reticular structure (20) of the ballistic armor (10) comprises a regularly repeated unit cell (21).

3. Optronic equipment (40) according to any one of claims 1 or 2, wherein the three-dimensional reticular structure (20) of ballistic armor (10) is auxetic.

4. Optronic equipment (40) according to any one of claims 1 to 3, in which the ballistic armor (10) also comprises one or more panels (30, 30').

5. Optronic equipment (40) according to claim 4, in which the ballistic armor (10) comprises two opposing panels (30, 30'), between which the three-dimensional reticular structure is interposed, so as to form a sandwich structure.

6. Method for producing the ballistic armor (10) of the optronic equipment (40) according to any one of claims 1 to 5, comprising a step of additive manufacturing of at least the three-dimensional reticular structure (20) of the ballistic armor (10).

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