ES2629521B1 - Anti-scratch shield with Stealth technology with optical damage detection system - Google Patents

Abstract

The composite shield of laser photonic sensing with Stealth technology is described. # The shield consists of a laminate of carbon fibers and aromatic polyamide with a ferromagnetic polymer matrix and an outer coating of ferromagnetic nanoparticles. Following the principles of Stealth technology to reduce its visibility to radar to the maximum. # Internally the laminate incorporates an optoelectronic assembly based on the limitations of transmission of the laser light in optical fiber, in an arrangement that allows the measurement of impacts, breaks or torsions. # Its use has been exemplified, designing the armor for a UGV (unmanned ground vehicle) with anti-radar geometry on a faceted prolate spheroid.

Description

Technical Field of the Invention

The field of application of the invention is within the industrial sector, dedicated to aerospace and safety manufacturing, which require high mechanical performance, sensing materials, including Stealth properties.

Stealth technology (because of its English-language terminology) is called furtive technologies, popularly called "invisibility." These technologies encompass several concealment techniques, mostly used in airplanes and ships, to make them less visible to radar. Stealth technology usually involves the design of the fuselage or chassis of the vehicle through a faceted geometry of flat faces.

Background or prior art

The laser photonic shielding system, is a proposal that aims to solve the current problem for the real-time diagnosis of a shield, also responds to the industrial need to create more resistant materials, with improved properties, among which is also the technology of reduced visibility to radar (Stealth).

In this shield, the latest generation composite materials are combined with an internal laser optoelectronic system in a single system, to merge the advantages and special properties of both.

Stealth technology or stealth technology has developed low visibility systems against radar in recent decades. It is used mostly in airplanes and ships destined for defense. The new mathematical advances of algorithms with Bayesian filters, together with the improvements in the sensors and processing of the radars themselves, have recently lost their effectiveness; But not all its importance. Therefore, they continue to develop stealth technologies in different vehicles, integrating them into their equipment under the concept of low observability. Currently they design these vehicles looking to find an optimal combination of all functionalities, with reduced radar detectability; without limiting its operational capabilities.

Brief Description of the Invention

The object of the invention is an anti-radar shield with stealth technology with an optical damage detection system. The optical damage detection system is an optoelectronic system, and is combined in a composite material: it is a laminated material in which layers of carbon fiber, aromatic polyamide (such as Kevlar ® or polyparaphenylene terephthalamide) and polymer matrix are used magnetic, with a coating of ferromagnetic nanoparticles. It is also capable of using anti-radar geometry, following the principles of Stealth technology to reduce its visibility to radar to the maximum; so that it deflects and absorbs most of the radiation. Internally, an optical and electronic assembly is installed with a fiber optic network on its entire surface bent at the limit of total internal reflection, as a sensor of impacts, breaks or torsions.

The main novelty is the incorporation of a sensorized optoelectronic system to a shield; in which the Stealth technology of visibility reduction before manufacturing radar has been implemented in a simpler way.

Among the advantages of this material, the ability to permanently check the damage status, without the need for destructive analysis, stands out. It can withstand special conditions such as high temperature, high pressure, impacts

or exposure to an intense electromagnetic field. Combined with its low visibility properties before radars.

As for the proposed uses: the manufacture of aircraft fuselages could be found. In the automobile industry, speed and safety could be improved in the detection of an impact on airbag activation systems; replacing the electronic system with an internal optoelectronic, as bodywork.

For the industry in general, it would allow the manufacture of a high performance material, on which a check of the internal structural integrity can be carried out at any time, saving costs in subsequent tests.

Its application in the security industry: incorporating photonic sensing to protective vests with real-time damage diagnosis.

Brief description of the drawings:

Figure 1: allows to complete the description of the invention and facilitate its interpretation. It shows the following layer structure of the anti-scratch shield:

(one)

Coating of ferromagnetic nanoparticles with fixative.

(2)

Layers of carbon fiber fabric.

(3)

Internal aromatic poly amide fabric layers

(4)

Fiber optic assembly folded at the limit of total internal reflection (more details in figure 2).

(5)

Layers of aromatic polyamide fabric that form the inside face of the laminate

(6)

Polymeric matrix with added ferromagnetic particles or magnetic resin.

(7)

Fiber optic connectors (input and output).

(8)

Programmable laser transmitter, receiver and automaton set for detecting changes in light transmission.

In figure 2: the pattern of placement of the optical fiber in which it is folded in the total internal reflection limit is shown covering the entire fiber optic assembly (4) of figure 1. This fiber optic assembly (4) it is placed between the layers of aromatic polyamide fabric (3, 5) of Figure 1.

In Figure 3: it is shown by exemplifying the use of this material by designing on a UGV (unmanned land vehicle) with anti-radar geometry on a faceted prolate spheroid, in which the properties of the anti-radar shielding with stealth technology with optical system are optimized damage detection

(9)

Openings with Stealth design for the sensors.

(10)

Entry! central multipurpose output.

(eleven)

Wireless communications antenna

(12)

Part 4 is the upper moving part.

(13)

External defense battery.

(14)

Axis of rotation.

(fifteen)

UGV stands or limbs.

(16)

System Base

(17)

Wheels.

Description of the invention

The radiation shielding with stealth technology with optical damage detection system is a system composed of a laminated material in which an optoelectronic system is implemented.

The material is constructed from a plurality of layers comprising: layers of outer carbon fiber fabric (2), aromatic poly amide fiber (aramid, such as Kevlar®), which constitutes layers of aromatic poly amide fabric ( 3, 5), a ferromagnetic polymer matrix (6), a coating (1) of ferromagnetic nanoparticles (for which the use of magnetite is proposed) and in addition to the use of anti-radar geometry following the principles of Stealth technology, to decrease its visibility to radar to the maximum; in a way that deflects and absorbs radiation.

It is a RAM system (Radar Absorbent Material) that combines the physical-chemical qualities of carbon fiber and aromatic polyamide: the absorption of microwave radiation, lightness, thermal insulation, great mechanical resistance, as well as resistance to exceptional breakage

The use of epoxy resin is proposed as a thermoset polymeric matrix (6), in combination with ferromagnetic particles (such as magnetite) of micrometric or nanometric size, and in the outer surface layer (the most sensitive part in radar detection) a coating (1) with ferromagnetic nanoparticles to optimize the absorption of microwave radiation, which employ most radars.

The strength of the material is improved by applying vacuum in the process (to avoid air bubbles) and curing of the resin in an autoclave (improves the physical-chemical properties of the final material).

The optoelectronic system consists of a fiber optic assembly (4) installed according to figure 2 in the material, between the layers of aromatic paliamide fabric (3, 5) according to figure 1. As an emission, reception and processing system, install a laser module (a light source) and a light intensity sensor (the use of a photodiode is proposed). Both the laser and the receiver are connected to the composite material through the connectors to the fiber optic network (7). In addition, it includes a processing device for the detection of changes in the transmission of light, as a shock, breakage or torsion sensor.

The system can analyze the impacts, impacts, twists or bends of the material in real time in a non-destructive way. It is designed so that it can detect variations in the intensity of the laser light transmitted inside and through a processing system, analyze the damage of the shield.

The optical fiber that is placed in the folded material at the limit of total internal reflection, when it undergoes deformations or breaks, will also occur in the optical fiber; that it bends over the total internal reflection limit or breaks at some points; This will result in a decrease or cessation of light transmission. It has been exemplified on a laminate of carbon fiber and pallia, however, the same optoelectronic system could be installed to other ceramic or organic laminated materials, in which the assembly of the interior optical fiber maintains the same stiffness as the support material , so that impacts and breaks can be transferred to the sensed system.

The system is based on the calculation of the losses of intensity in the transmission of light in an optical fiber when a curvature of the same occurs, exceeding the limit of total internal reflection. This is a well-known problem mainly in the field of telecommunications, its mathematical development can be found in bibliography as in "Gerd Keizer, optic fiber communications", third edition of McGraw-HiII. Photonic shielding makes this problem an advantage, using it as a detection system.

As an example of use in which anti-radar armor is optimized with stealth technology with optical damage detection system, the construction of an unmanned ground vehicle, UGV (Unmanned Ground Vehicle) is proposed Figure 3. The geometry of the prototype is a spheroid prolate, with polygonal faces using obtuse and straight angles, avoiding sharp angles and edges to minimize diffraction. This geometry combines the best resistance to 3600 impacts, so that the angle from which it is concerned is indifferent, reducing vulnerable areas. The system with the laser photonic shielding together with this faceted design allows it to absorb and deflect the microwave radiation of the radars and hinder their location in a more efficient way.

Claims (4)

1. Anti-radar shielding with stealth technology with optical damage detection system, characterized in that it comprises:

-

a material composed of a plurality of layers;

-

an internal optoelectronic system that constitutes the optical damage detection system;

where the plurality of layers comprises internally a fiber optic assembly (4), bent at the total internal reflection limit, connected to a set (8) formed by: a laser emitter, a light receiver and a programmable device configured to process the alterations in the transmission of fiber light, and The composite material comprises: a layer of outer carbon fiber fabric (2); layers of aromatic poly amide fabric (3, 5) between which the fiber optic assembly (4) is located, and; a polymeric matrix (6) with added ferromagnetic particles.

2.

Anti-scratch shield with stealth technology with optical damage detection system according to claim 1, characterized in that it has an outer coating (1) containing ferromagnetic nanoparticles.

3.

Anti-scratch shielding with stealth technology with optical damage detection system according to claim 1, characterized in that the plurality of layers comprises layers of ceramic or organic materials.

Four.

Anti-radar shielding with stealth technology with optical damage detection system according to any of the preceding claims, characterized by

which is built in the form of a spheroid prolate on which a faceted design of stealth technology is used.