U.S. patent application number 13/819428 was filed with the patent office on 2013-06-27 for lightweight impact resistant panel.
The applicant listed for this patent is Gigi Simovich. Invention is credited to Gigi Simovich.
Application Number | 20130164484 13/819428 |
Document ID | / |
Family ID | 44718537 |
Filed Date | 2013-06-27 |
United States Patent
Application |
20130164484 |
Kind Code |
A1 |
Simovich; Gigi |
June 27, 2013 |
LIGHTWEIGHT IMPACT RESISTANT PANEL
Abstract
A Hollow lightweight panel made of high tensile strength rigid
material. The panel comprises multiple parallel elongated cavities.
The cavities are sealed and pressurized with gas. The gas pressure
acts to resist any deformation of the panel and thereby reinforces
and stabilizes the structure. The panel is suitable for use as
structural element in aircraft, spacecraft and road vehicles. The
panel is especially effective as armor element, as a lightweight
backing for hard layers and as rigid under belly and side panels
where required to be resistant to bomb and mine blasts.
Inventors: |
Simovich; Gigi; (Savion,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Simovich; Gigi |
Savion |
|
IL |
|
|
Family ID: |
44718537 |
Appl. No.: |
13/819428 |
Filed: |
November 20, 2011 |
PCT Filed: |
November 20, 2011 |
PCT NO: |
PCT/IL11/00899 |
371 Date: |
February 27, 2013 |
Current U.S.
Class: |
428/69 ;
428/314.4 |
Current CPC
Class: |
F41H 5/24 20130101; Y10T
428/249976 20150401; Y10T 428/231 20150115; F41H 5/02 20130101;
F41H 7/042 20130101 |
Class at
Publication: |
428/69 ;
428/314.4 |
International
Class: |
B32B 3/12 20060101
B32B003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2010 |
IL |
209950 |
Claims
1. A lightweight impact resistant panel comprising; a) Two
peripheral skin surfaces made of high tensile strength material,
and b) a lightweight core structure is disposed between the two
skin surfaces, and attached to the skin surfaces, wherein c) the
core comprises a pattern of sealed fluid pressurized cavities
containing a fluid, and d) whereby the pressure in the cavities
increases the stability of the structure against buckling, and
makes the structure more resistant to impact.
2. A lightweight impact resistant panel comprising; a) Two
peripheral skin surfaces made of high tensile strength material,
and b) a lightweight core structure is disposed between the two
skin surfaces, and attached to the skin surfaces, and, c) the core
comprises a pattern of sealed cavities, and d) the cavities are
filled with an incompressible fluid, and e) wherein the panel's
cavities self pressurize when the panel is subjected to Impact,
whereby the pressure in the cavities increases the stability of the
structure against buckling, and makes the structure more resistant
to impact.
3. A lightweight impact resistant panel according to claim 1
wherein the fluid is a gas.
4. A lightweight impact resistant panel according to claim 1
wherein the panel is comprised in an anti ballistic armor
arrangement.
5. A lightweight impact resistant panel according to claim 1
wherein the panel is comprised in a vehicle structural body
arrangement.
6. A lightweight impact resistant panel according to claim 1
wherein the panel's core and peripheral surfaces is formed by metal
extrusion and are of a constant sectional shape.
7. A lightweight impact resistant panel according to claims 1,
wherein the panel's core and peripheral surfaces is formed by FRP
pultrusion, and are of a constant sectional shape.
8. A lightweight impact resistant panel according to claim 6,
wherein the panel comprises self sealing means.
9. A lightweight impact resistant panel according to claim 7,
wherein the panel comprises self sealing means.
10. The lightweight resistant panel of any claims 1 wherein the
cavities comprise valves for pressurizing.
Description
PRIORITY INFORMATION
[0001] This National Stage Entry claims priority to Israeli Patent
No: 209950 filed on Dec. 13, 2010.
FIELD OF THE INVENTION
[0002] This invention is in the field of vehicle structural element
and anti ballistic armor.
[0003] Definitions
[0004] In this description an incompressible fluid will refer to a
liquid or other substance that will undergo small volumetric change
when subjected to high isostatic pressure, and the material will
not remain solid, and flow, when subjected to shear forces, for
example: water, oil, slurry, paste, sand, ceramic powder and
tar.
[0005] In this description a fluid will refer to a gas, a liquid or
incompressible fluid as described above.
[0006] In this description a vehicle will refer to space, ground,
air, and water borne vehicles like cars, drones, airplanes
satellites, tanks and ships.
BACKGROUND OF INVENTION
[0007] Inflatable structures are known to be used in tents made of
impervious fabric in the form of interconnected long gas tight
chambers. This structure is only at its functional shape and rigid
when inflated.
[0008] When deflated the structure is not stable it collapses and
looses its useful shape.
[0009] In patent application WO2007064367 an armor apparatus is
disclosed that comprises a layer of parallel pressurized tubes that
contain fire retardant, among other chemicals, Silicon gel is
interposed between the tubes.
[0010] The tubes while providing structural rigidity along their
length provide little or no substantial rigidity in lateral
direction.
[0011] Many types of lightweight panels are used in the field of
aviation, vehicles structure and armor that employ a lightweight
core sandwiched between two sheets made of metal or fiber
reinforced plastic, (FRP).
[0012] The core holds the sheets apart and thus provide high
bending moment of inertia to the panels.
[0013] When trying to design a lighter panel structure, the first
choice is to increase the core width and to reduce the width of the
peripheral skin surfaces; this will increase the overall moment of
inertia while maintaining the weight low.
[0014] However the increase of the width of the core and the
reduction of the thickness of the peripheral surfaces causes a
reduction in the panel stability and the panel may buckle locally
when loaded.
[0015] The lightweight core can be for example a honeycomb of
Aluminum foil, rigid foam, Balsa wood and metal fin structure.
[0016] Hollow extruded panels, where a fin structure and enclosing
peripheral sheets are extruded as one unit, are also known.
[0017] When pressure or bending moment is applied to such a panel,
the core is compressed. In order to maintain the peripheral sheets
apart under this compression, the core must be strong and
rigid.
[0018] When the core fails due to local buckling or other
deformation, the peripheral sheets become attached, the panel's
moment of inertia is reduced and the panel losses it's high
rigidity. It is the purpose of the present invention to provide a
lightweight rigid and impact resistant panel to vehicles and to
lightweight armor arrangements. This purpose is achieved in part by
increasing the stability of panels that comprise thin and normally
low stability skin surfaces.
SUMMARY OF THE INVENTION
[0019] It is to be understood that both the foregoing general
description and the following detailed description present
embodiments of the invention and are intended to provide an
overview or framework for understanding the nature and character of
the invention as it is claimed. The accompanying drawings are
included to provide a further understanding of the invention and
are incorporated into and constitute a part of this specification.
The drawings illustrate various embodiments of the invention and,
together with the description, serve to explain the principles and
operations of the invention but not to limit the invention to these
descriptions only.
[0020] The present invention relates to lightweight panel
comprising at least two peripheral skin surfaces made of high
tensile strength material. The panel comprises a lightweight core
interlayer. In this invention the core interlayer is characterized
in comprising a pattern of sealed gas pressurized cavities. The
core interlayer further comprises a high strength structure which
defines the cavities and holds the skin surfaces in place against
the action of the gas pressure.
[0021] The core interlayer pattern can be, for example, a series of
parallel cavities, a fined structure like honeycomb, or random
pattern shaped metal foam.
[0022] Unlike the inflated tent structure, the gas pressure is not
essential to obtain the panel's shape, its main contribution is
hidden from the eye and it is manifested in a favorable stress
regime which develops in the structure and increases its
stability.
[0023] The increased stability also enables to design a lighter and
more rigid panel with thinner peripheral surfaces and with lighter
or thicker core.
[0024] In one preferred embodiment of the present invention, panels
are chosen to have skin surfaces and a core pattern with parallel
cavities made of the same material, it can sometimes be
advantageous to form such a panel by extrusion or pultrusion.
[0025] In this embodiment, the boundary between the core and the
peripheral surfaces can sometimes be hard to define.
[0026] Each cavity is sealed with appropriate plugs that are
provided at the each cavity edge.
[0027] Pressurized gas or air can be introduced into the cavities
through valves that can be fitted to the plugs.
[0028] ihe gas pressure can also be monitored and maintained
periodically through such valves. When the core cavities are
pressurized, tension develops in the peripheral skin surfaces and
in the core solid structure pattern, This pressurization increases
the stability of the structure. It is the purpose of this invention
to provide a lightweight panel of high stability and high
resistance to local buckling, to be used in structural element in
vehicles, like car doors that are safer against collisions.
[0029] The panel of the present invention can be used in aircraft,
spacecraft and missile skins.
[0030] The panel can easily be shaped to be single curved or
cylindrical.
[0031] It is the further purpose of this invention to provide a
lightweight panel of high stability, high resistance to local
buckling and high resistance to impact, to be used in armoring
element in vehicles and in personal body armor.
[0032] The use of gas pressurization to provide pre-stress to armor
panel has the following advantages:
[0033] Pressurized gas is lightweight.
[0034] In the high pressure gas cavities the gas acts to absorb
energy from external penetrating objects,
[0035] The tensioned peripheral skins walls have increased lateral
wave velocity and increased ductility; this increases the amount of
energy that can be absorbed in high velocity impact. U.S. Pat. No.
5,275,873 reveals that a remarkable 23 percent increase in V50
values was observed by subjecting Kevlar.RTM. fabrics to tension
during ballistic tests.
[0036] When the panel's core comprises long cavities, a lost in
cavity pressure can cause a weakening of the panel.
[0037] A rupture in the panel's skin can also cause a harmful
discharge of energetic gas. In order to reduce this risk, the
present invention provides an embodiment that comprises self
sealing cavity means. These means can avoid or delay the discharge
of gas in case of a small rupture. One method of obtaining a self
sealing cavity is to dispose lightweight sealers that would conform
to the shape of the cavity's cross section and that would be
allowed to move in the cavity.
[0038] In an event of a small rupture the sealers would drift in
the cavity by the flowing gas towards the hole and seal it.
[0039] The sealers are preferably made with some rubber that can
deform under pressure and seal a deformed cavity.
[0040] Another method of obtaining a self sealing cavity is to
dispose separation walls in the cavity; each wall comprises a self
sealing valve between the two separated cavity sections.
[0041] The self sealing valve would close in case a high pressure
difference would occur between the separated sections.
[0042] The valve will be open when the pressure difference is
small.
[0043] The valve will allow the filling and discharging of gas in
production and maintenance and would stop or delay the gas
discharge in case of a local rupture.
[0044] The pressures that can be practiced are from about 1 MPa for
thin walled panels to pressures in the order of 100 Mpa for compact
thick walled ballistic resistant panels.
[0045] Creep, tensile strength, fatigue and temperature and work
regime are to be taken into consideration when designing a
panel.
[0046] In another preferred embodiment of the invention a
lightweight panel comprising at least two peripheral skin surfaces
made of high tensile strength material. The panel comprises a
lightweight core interlayer. In this embodiment the core interlayer
is characterized in comprising a pattern of sealed cavities
pressurized with incompressible fluid. When using water for example
instead of pressurized gas, a burst of a panel would be much less
energetic and therefore safer.
[0047] Another advantage of using a incompressible fluid is that
the panel's cavities self pressurize when the panel is subjected to
impact or deformation. This phenomenon is used by those who bend
tubes by filling them first with sand or liquid.
[0048] In this embodiment the incompressible fluid disposed in the
panel's core sealed cavities can increase its stability even
without pre-pressurizing it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The accompanying drawings, which are incorporated in and
form a part of this specification, illustrate embodiments of the
invention and together with the description, serve to explain by
way of example only, the principles of the invention:
[0050] FIG. 1 is a schematic depiction in isometric projection with
sectional view of a hollow lightweight panel made of high tensile
strength rigid material.
[0051] The panel's core comprises multiple parallel elongated
cavities.
[0052] The cavities are sealed and pressurized with gas; the
cavities are cylindrical and arranged in parallel in a single
layer.
[0053] FIG. 2 is a schematic depiction in isometric projection with
broken view of a hollow lightweight panel made of high tensile
strength rigid material.
[0054] The panel's core comprises multiple cylindrical elongated
cavities.
[0055] The cavities are sealed and pressurized with gas, the
cavities arranged in parallel in two layers.
[0056] FIG. 3 is a schematic depiction in isometric projection with
broken view of a hollow thin walled lightweight panel made of high
tensile strength rigid material.
[0057] The panel's core comprises multiple cavities.
[0058] The cavities are sealed and pressurized with a gas; the
panel comprises a pattern of elongated cavities and fins arranged
in parallel in a single layer.
[0059] FIG. 4 is a schematic depiction in isometric projection with
sectional view of a hollow lightweight cylindrical shaped panel,
made of high tensile strength rigid material.
[0060] The panel's core comprises multiple cavities.
[0061] The cavities are sealed and pressurized with gas; the board
comprises multiple elongated cylindrical cavities arranged in
parallel to the main cylindrical panel's axis.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] As will be appreciated the present invention is capable of
other and different embodiments than those discussed above and
described in detail below, and its several details are capable of
modifications in various aspects, all without departing from the
spirit of the invention. Accordingly, the drawings and description
of the embodiments set forth below are to be regarded as
illustrative in nature and not restrictive.
[0063] FIG. 1 is a schematic depiction in isometric projection with
sectional view of a hollow lightweight panel 11 made of high
tensile strength rigid material preferably by an Aluminum alloy
extrusion.
[0064] The panel's core comprises multiple parallel elongated
cavities 10.
[0065] The cavities 10 are sealed and pressurized with gas; the
cavities are cylindrical and arranged in parallel in a single
layer.
[0066] The cavities are sealed by plugs (not shown) at their ends;
each cavity is fitted with a filling valve (not shown).
[0067] FIG. 2 is a schematic depiction in isometric projection with
broken view of a hollow lightweight panel 21 made of high tensile
strength rigid material.
[0068] The panel's core comprises multiple cylindrical elongated
cavities 20.
[0069] The cavities are sealed and pressurized with gas; the
cavities are arranged in parallel in two layers.
[0070] The cavities are sealed by plugs (not shown) at their ends;
each cavity is fitted with a filling valve (not shown).
[0071] FIG. 3 is a schematic depiction in isometric projection with
broken view of a hollow thin walled lightweight panel 31 made of
high tensile strength rigid material.
[0072] The panel's core comprises multiple cavities 30.
[0073] The cavities are sealed and pressurized with a gas; the
panel comprises a pattern of elongated cavities and fins 32
arranged in parallel in a single layer.
[0074] The shape of the cavity is chosen as the shape that would
provide the maximum volume for given fin and cavity perimeter
length.
[0075] The cavities are sealed by plugs (not shown) at their ends;
each cavity is fitted with a filling valve (not shown).
[0076] FIG. 4 is a schematic depiction in isometric projection with
sectional view of a hollow lightweight cylindrical shaped panel 42
comprising an internal main surface 41, made of high tensile
strength rigid material.
[0077] The panel's core comprises multiple cavities 40.
[0078] The cavities are sealed and pressurized with gas; the board
comprises multiple elongated cylindrical cavities arranged in
parallel to the main cylindrical panel's axis.
[0079] The cavities are sealed and interconnected (not shown) at
their ends; the cavities are fitted with a filling valve (not
shown).
[0080] This embodiment can reduce the weight is rocket skin
envelopes where high rigidity and low weight are critical.
* * * * *