U.S. patent application number 13/267519 was filed with the patent office on 2012-08-16 for helmet design utilizing nanocomposites.
This patent application is currently assigned to Kinetica Inc.. Invention is credited to Alan Ira Faden, Thomas E. Twardowski, JR..
Application Number | 20120204327 13/267519 |
Document ID | / |
Family ID | 46635713 |
Filed Date | 2012-08-16 |
United States Patent
Application |
20120204327 |
Kind Code |
A1 |
Faden; Alan Ira ; et
al. |
August 16, 2012 |
HELMET DESIGN UTILIZING NANOCOMPOSITES
Abstract
Disclosed herein is a composite structure for deflecting and
spreading kinetic energy transmission after various types of
impacts utilizing nanocomposites. The structure has a first
composite layer including a discrete reinforcement and a continuous
binder. The first composite layer is an outside layer that comes in
contact with an object. The structure has at least one subsequent
composite layer that is adjacent to the preceding layer and
includes a discrete reinforcement and a continuous binder. The
discrete reinforcement is made of particles and can have varying
sizes and materials. In one embodiment, the particles in layer
reinforcements have a progressively smaller size than preceding
layers.
Inventors: |
Faden; Alan Ira; (Baltimore,
MD) ; Twardowski, JR.; Thomas E.; (Morrisville,
PA) |
Assignee: |
Kinetica Inc.
Baltimore
MD
|
Family ID: |
46635713 |
Appl. No.: |
13/267519 |
Filed: |
October 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61442469 |
Feb 14, 2011 |
|
|
|
Current U.S.
Class: |
2/411 ; 2/455;
428/323; 428/325 |
Current CPC
Class: |
B32B 2264/10 20130101;
Y10T 428/24983 20150115; Y10T 428/24612 20150115; B32B 27/20
20130101; B32B 2264/107 20130101; F41H 1/04 20130101; B32B 3/08
20130101; B32B 7/02 20130101; B32B 2260/025 20130101; B32B 5/30
20130101; A41D 31/285 20190201; F41H 5/0428 20130101; A42B 3/063
20130101; B32B 5/22 20130101; Y10T 428/1334 20150115; Y10T 428/24
20150115; B32B 3/26 20130101; Y10T 428/31504 20150401; Y10T
428/24661 20150115; B32B 5/16 20130101; B32B 2605/00 20130101; Y10T
428/24512 20150115; B32B 2571/00 20130101; B32B 1/00 20130101; F41H
1/08 20130101; Y10T 428/1334 20150115; B32B 2264/101 20130101; B32B
2264/12 20130101; B32B 2419/00 20130101; Y10T 428/24562 20150115;
B32B 2437/04 20130101; Y10T 428/24992 20150115; A42B 3/064
20130101; B32B 5/145 20130101; C08L 23/02 20130101; Y10T 428/25
20150115; A44B 18/0076 20130101; Y10T 442/637 20150401; Y10T
442/637 20150401; Y10T 428/31678 20150401; B32B 2262/10 20130101;
B32B 3/12 20130101; B32B 2260/046 20130101; B32B 2307/56 20130101;
Y10T 428/252 20150115; F41H 5/007 20130101; A43B 13/189 20130101;
F41H 5/0492 20130101 |
Class at
Publication: |
2/411 ; 2/455;
428/323; 428/325 |
International
Class: |
A42B 3/04 20060101
A42B003/04; B32B 5/16 20060101 B32B005/16; B32B 7/02 20060101
B32B007/02; A41D 13/015 20060101 A41D013/015 |
Claims
1. A structure for deflecting and spreading kinetic energy, the
structure comprising: a first composite layer comprising a
plurality of particles, each particle of the plurality of particles
having a first size, wherein the first composite layer comprises a
discrete reinforcement and a continuous binder; and at least one
subsequent composite layer that is adjacent to the first layer, the
at least one subsequent composite layer comprising particles of a
second size which differs from the first size.
2. The structure of claim 1, wherein the first composite layer is
an outside layer that comes in contact with an object.
3. The structure of claim 1, wherein the particles in the first
composite layer are ceramic.
4. The structure of claim 1, wherein the particles in the first
composite layer are glass.
5. The structure of claim 1, wherein the discrete reinforcement is
at least one type of particle.
6. The structure of claim 1, wherein the discrete reinforcement
comprises particles having a size greater than 1 micron.
7. The structure of claim 1, wherein the continuous binder binds
particles together to yield the first composite layer.
8. The structure of claim 7, wherein the continuous binder in the
first composite layer is a polymer.
9. The structure of claim 1, wherein the at least one subsequent
composite layer comprises a discrete reinforcement and a continuous
binder.
10. The structure of claim 9, wherein the particles in at least one
subsequent composite layer are ceramic.
11. The structure of claim 9, wherein the particles in at least one
subsequent composite layer are glass.
12. The structure of claim 9, wherein the continuous binder in at
least one subsequent composite layer is a polymer.
13. The structure of claim 9, wherein the discrete reinforcement in
at least one subsequent composite layer is at least one type of
particle.
14. The structure of claim 9, wherein the discrete reinforcement
comprises particles having a size smaller than the first layer.
15. The structure of claim 9, wherein the discrete reinforcement
has a progressively smaller size than preceding layers.
16. The structure of claim 1, wherein the structure is used in one
of a helmet, body armor, a vehicle and a building.
Description
PRIORITY
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/442,469, filed 14 Feb. 2011, the contents of
which are herein incorporated by reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to safety helmet design and
more specifically to reducing kinetic energy transmission after
various types of impacts by utilizing nanocomposites.
[0004] 2. Introduction
[0005] In the United States, hundreds of thousands of people each
year are involved in athletic, cycling or motorcycle accidents
resulting in head injury. Much of the subsequent damage is caused
by the transmission of kinetic energy to the brain, as well as
shear forces. Although existing bicycle helmets reduce deaths and
brain injuries, current designs focus more on aesthetics and
aerodynamic performance than safety, in part due to market demands.
In addition, the helmet industry is essentially self-regulating and
therefore not likely to make significant improvements to helmets
unless the improvements prove to be cost-effective and/or markedly
more effective. Advances in polymeric materials provide novel
approaches to helmet design and construction. Significant
improvements in viscoelastic (active) dampening, low loss
elastomers, and gradient rigidity materials have already given rise
to enhanced athletic equipment and protective gear.
[0006] Crashes and impacts to the head in sports often result in
head trauma due to the rigid construction of helmets. The severe
consequences of concussive brain injuries have become increasingly
recognized in many sports, particularly recently in professional
football and ice hockey. It has also long been recognized that
boxers often suffer significant cognitive decline, even in
non-professional contests where protective head gear is required.
Professional and college sports teams would likely switch to a new
type of helmet, if such a design were clearly shown to reduce
post-traumatic brain injury.
[0007] In addition to athletics, improved helmet designs have
applications in the military. Brain injury is the leading cause of
disability for military personnel deployed in Iraq and Afghanistan.
Although military helmet designs have improved in recent years,
they are intended primarily to prevent missile/shrapnel
penetration, and do little to reduce the energy transmitted to the
brain, which is a major contributor to subsequent disability. The
mechanisms of traumatic brain injury due to blast forces remain
unclear, but brain injuries related to explosives are by far the
most common cause of death and disability in Iraq and Afghanistan.
Experimental evidence indicates that the use of advanced body armor
may contribute to the increase in brain injuries, both by
protecting against death from injury to major non-brain organs such
as the lung, and possibly by transmitting kinetic energy through
larger blood vessels to the brain.
[0008] Existing helmet designs do not adequately address the
critical problem:kinetic energy from the impact is transmitted to
the brain through primary, secondary and tertiary mechanisms. This
results in concussion, brain damage and even death. Improvements in
helmet design are needed.
SUMMARY
[0009] Additional features and advantages of the disclosure will be
set forth in the description which follows, and in part will be
obvious from the description, or can be learned by practice of the
herein disclosed principles. The features and advantages of the
disclosure can be realized and obtained by means of the instruments
and combinations particularly pointed out in the appended claims.
These and other features of the disclosure will become more fully
apparent from the following description and appended claims, or can
be learned by the practice of the principles set forth herein.
[0010] Disclosed is a structure for improved safety helmet design
that reduces both the kinetic energy induced by impact and
rotational forces. The safety helmet will better protect the brain
by limiting both direct missile trauma and secondary kinetic
effects. Distributing the force that a penetrating object applies
is typically accomplished by a hard shell. Metals, reinforced
Kevlar or fiberglass composites traditionally have accomplished
this role, but new composites offer improvement. The main failure
of most headgear is that a blunt, distributed force can cause
significant trauma if the force is not dissipated in other ways
than transmission to the skull. The structure disclosed herein
dissipates damaging forces utilizing nanocomposites. In addition to
helmet design, the principles disclosed herein can also apply to
other types of body armor such as chest protectors and bullet proof
vests as well as buildings or other structures exposed to
projectiles or explosives. The layering approach distributes the
forces laterally and away from the skull based on the structure and
interaction between layers in the structure.
[0011] The safety helmet or other armor has a first composite layer
that receives contact of an object which results in a transfer of
kinetic energy. The first composite layer is composed of a discrete
reinforcement and a continuous binder. The continuous binder binds
particles to one another to yield the composite in the first layer
of the safety helmet. The discrete reinforcement is composed of
particles having a first size. Particles can have differing sizes,
shapes and can be different materials.
[0012] The safety helmet or other armor has one or more subsequent
composite layers adjacent to the preceding layer that transfers
kinetic energy laterally with respect to the skull. Subsequent
layers are each composed of a discrete reinforcement and a
continuous binder. The discrete reinforcement is composed of
particles that can have differing sizes, shapes and can be
different materials. The continuous binder binds particles to one
another to yield the composite in subsequent layers of the safety
helmet. In one embodiment, layer reinforcements have a
progressively smaller size than the preceding layers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to describe the manner in which the above-recited
and other advantages and features of the disclosure can be
obtained, a more particular description of the principles briefly
described above will be rendered by reference to specific
embodiments thereof which are illustrated in the appended drawings.
Understanding that these drawings depict only exemplary embodiments
of the disclosure and are not therefore to be considered to be
limiting of its scope, the principles herein are described and
explained with additional specificity and detail through the use of
the accompanying drawings in which:
[0014] FIG. 1 illustrates a side view of a safety helmet with
layers each having a discrete reinforcement and a continuous
binder;
[0015] FIG. 2 illustrates an exemplary safety helmet method
embodiment;
[0016] FIG. 3 illustrates a side view of safety helmet layers;
and
[0017] FIG. 4 illustrates an alternate side view of safety helmet
layers.
DETAILED DESCRIPTION
[0018] Various embodiments of the disclosure are discussed in
detail below. While specific implementations are discussed, it
should be understood that this is done for illustration purposes
only. A person skilled in the relevant art will recognize that
other components and configurations may be used without parting
from the spirit and scope of the disclosure.
[0019] The present disclosure addresses the need in the art for
improved safety helmet designs. A safety helmet design is disclosed
that reduces both the kinetic energy induced by impact and
rotational forces. A brief introductory description of safety
helmets is provided, followed by a discussion of mathematical
modeling used to optimize helmet layer design. A more detailed
description of improved safety helmet designs using nanocomposites
will then follow. While a helmet is used in the example embodiment,
the layering principles can also be applied to a wall, body armor,
a vehicle, or any protective layer that could use the principles
disclosed herein. Accordingly, various embodiments of the
disclosure include a wall having a series of layers and disclosed
herein, body armor having the series of layers as well as a vehicle
having an outer covering including the series of layers disclosed
herein. The disclosure proceeds to discuss primarily a helmet
embodiment.
[0020] Traditional design for both military and recreational
helmets includes a rigid outer material to prevent penetration of
the skull and brain, as well as some type of lining material to
absorb some of the shock and to enhance comfort. However, few
modern designs adequately address the critical problems leading to
brain damage:kinetic energy transmitted to the brain and rotation
(particularly axial acceleration/deceleration).
[0021] By using novel materials and composites that are organized
upon mathematically defined principles to maximize the relative
dissipation of transmitted kinetic energy, as well as to limit
rotational components, the disclosed design for helmets and body
armor should markedly reduce posttraumatic brain injuries from
various types of insults and impacts. The initial target outcome is
a set of disruptive technological advances in helmet design that
improve the survivability of impact trauma to the head for use in
military and civilian applications.
[0022] Stacks of various materials can be used in experiments to
determine the abilities of the various materials to dissipate and
spread out external forces. Mathematical modeling can be used to
extrapolate from experimental data to the behaviors of actual
helmets constructed of the various material stacks by constructing
local models and constructing local-to-global models.
[0023] A local model refers to a mathematical model of a single
cylindrical stack. Such a model allows calculation, based upon an
exogenous force exerted on the top surface of the stack, the amount
of force transmitted to a particular point either internal to the
stack or on the surfaces of the stack.
[0024] Consider a particular stack on which is imposed a
rectangular coordinate system (x,y,z). Further, suppose that the
vector function F(x,y,z) represents the magnitude of the force
experienced at point (x,y,z) of the stack from a known exogenous
impact on the stack. Yet further, suppose that experimental data
results in measurement of the value of F(x,y,z) at N particular
stack points, say
(x.sub.i, y.sub.i,z.sub.i) (i=1, . . . , N)
[0025] Based on the geometric description of the stack, the
properties of the materials composing the stack, and an analysis of
the physics of force transmission through the stack, the general
mathematical form of the function F(x,y,z), up to a set of
parameters. For example, in a simple case, the function might have
the form:
F(x,y,z)=ax+by+cz
a linear function, involving three parameters a,b,c, which must be
determined. Generally, the experimental data results in an
over-determination of a,b,c, so that no set of values for a,b,c
exactly matches the experimental data. The best that can be done is
to determine the values of a,b,c is some "optimal fashion"--that
is, so that some error function is minimized. The most common such
error function is the sum of squares function:
E ( a , b , c ) = i = 1 N ( F ( x i , y i , z i ) - ax i - by i -
cz i ) 2 ##EQU00001##
[0026] In case F(x,y,z) is linear, as in the above example, the
determination of a,b,c is just the well-known problem of linear
regression analysis. However, in actual practice, the function F
may involve more or fewer parameters and is generally highly
non-linear, especially for materials with complicated behaviors. In
such instances, the error function E is a much more complex
function and the problem of minimizing the sums of the squares of
the errors is a non-linear optimization problem, which we have had
considerable experience addressing.
[0027] In order to proceed from the local models to actual helmets
configurations, an accepted technique from finite-element analysis
can be used, namely subdividing a helmet configuration into a large
number of elemental configurations, the analysis of each of which
can be handled by a local model, and then analyzing the interaction
among adjacent elemental configurations.
[0028] For the case of the helmet configurations, the surface of
the helmet can be divided into a triangular lattice. Corresponding
to each triangle, a triangular prism can be obtained by a radial
cut into the helmet along each side of the triangle. Each
triangular prism can be regarded as embedded within a circular
stack and thus subject to the analysis of a local model, which
would allow an assessment of the transmission of forces between
adjacent prisms in response to an exogenous force anywhere on the
helmet surface.
[0029] Of particular interest would be the proportion of the
initial energy which is transmitted to the bottom of the prisms,
the maximum forces transmitted, and their respective locations.
This information can be used to compare the effectiveness of
various material stacks and helmet configurations.
[0030] Having disclosed some mathematical modeling used to optimize
helmet layer design, the disclosure now turns to FIG. 1 and FIG. 2,
which illustrate an improved safety helmet design that reduces both
the kinetic energy induced by impact and rotational forces. The
safety helmet will better protect the brain by limiting both direct
missile trauma and secondary kinetic effects. The safety helmet 102
receives contact of an object that transfers kinetic energy to a
first composite layer 104, 202 which results in a transfer of
kinetic energy. The first composite layer in the safety helmet uses
a discrete reinforcement 106 and a continuous binder 108. The
discrete reinforcement 106 includes particles having a first size.
The safety helmet 102, 204 uses a second composite layer 110
including a discrete reinforcement 112 and continuous binder 114
adjacent to the first composite layer to transfer kinetic energy
laterally with respect to the skull, the discrete reinforcement 112
having additional sizes of particles. Optionally, subsequent
composite layers 116 adjacent to a preceding layer 110 are possible
that transfer kinetic energy laterally with respect to the skull.
Subsequent composite layers contain a discrete reinforcement 118
and a continuous binder 120. The continuous binder can be a
material such as a polymer. A polymer is a large molecule composed
of repeating structural units, the units typically connected by
covalent chemical bonds. Polymers are both natural and synthetic
materials with varying properties. Natural polymeric materials
include shellac and cellulose and synthetic polymers include
neoprene, PVC, silicone and more.
[0031] The discrete reinforcement in each layer is composed of
particles that can have differing sizes and can be different
materials such as ceramic or glass. The reinforcement includes at
least one type of particle and has particles with a size greater
than one micron in one embodiment. In another aspect, the particles
can be of a size of 1 micron or smaller in diameter. The particles
can be any spherical particulates, such as silica, carbon black,
iron oxide or alumina. Alternately, they could be plates of
silicates such as clays containing montmorillonite, mica or
graphene. Other alternate materials can be fibers of silicates such
as immogolite, carbon nanotubes, biogenic ceramic or organic
crystalline fibers. The particular shape of the particles could
vary depending on the application (helmet, body armor, vehicle
armor, etc.). For example, the particles could be cylindrical,
spherical, cubic, rectangular, pyramid shaped, etc. The continuous
binder binds particles to one another to yield the composite in the
first layer of the safety helmet. In one embodiment, layer
reinforcements have a progressively smaller size than the preceding
layers, creating multiple scales of reinforcement. A helmet can
have any number of layers containing a discrete reinforcement and
continuous binder and can be used in conjunction with other shock
absorbing layers.
[0032] FIG. 3 illustrates a side view of safety helmet layers
utilizing nanocomposites. For example, a first layer 302 comes in
direct contact with an object 304, such as shrapnel from an
exploded road-side bomb. The object does not necessarily contact
the helmet at a 90 degree angle; any angle is contemplated such as
45 or 135 degree angles 306, 308. The method disclosed herein
applies to an object contacting the helmet at any angle. The first
composite layer 302 contains a discrete reinforcement 310 and a
continuous binder 312. The discrete reinforcement 310 has particles
of a first size such as 100 microns that are glass. The continuous
binder in the first composite layer 312 is a polymer such as
silicone. The discrete reinforcement 316 in the second composite
layer 314 has particles of a second size such as 50 microns that
are ceramic. The continuous binder 318 is a polymer and can be the
same material as the binder in the first layer or can be different
such as neoprene. The third composite layer 320 has a discrete
reinforcement 322 that contains particles of a third size such as
10 microns and can be a mixture of glass and ceramic particles. The
continuous binder in the third composite layer 324 is a polymer and
can be the same or different than binders in preceding layers. The
number of composite layers in a structure is variable and the
provided example should not be limiting in any way. Note the
presence of multiple composite layers introduces the potential for
damage along the layer interfaces 328, while the impact cone 326 is
blunted rapidly by stress transfer to the structure. The multiple
scales of reinforcement provide an outer layer reinforced with
large particles that can interact well with large objects. The
force on these relatively large particles is transmitted through
mediating layers of particles of decreasing size to blunt the force
cone and distribute the load across the entire helmet shell.
[0033] Alternately, the discrete reinforcement contains particles
that are the same size or larger than particles in the preceding
layer. FIG. 4 illustrates an alternate side view of safety helmet
layers. The first composite layer 408 comes in direct contact with
an object 402. The object does not necessarily contact the helmet
at a 90 degree angle; any angle is contemplated such as 45 or 135
degree angles 404, 406. The method disclosed herein applies to an
object contacting the helmet at any angle. The first composite
layer 408 contains a discrete reinforcement 410 and a continuous
binder 412. The second composite layer 414 is adjacent to the
preceding layer, the first composite layer 408, and the discrete
reinforcement 416 contains additional sizes of particles, such as
particles smaller than the particles in the first layer 410. The
third composite layer 418 is adjacent to the preceding layer, the
second composite layer 414, and contains additional sizes of
particles, such as particles in 420 larger than the particles in
the second layer 416. Particle sizes in the discrete reinforcement
can vary, such as having multiple sizes of particles in a layer.
The helmet structure containing layers having particles with
different sizes disclosed herein can distribute a force that a
penetrating object applies.
[0034] The various embodiments described above are provided by way
of illustration only and should not be construed to limit the scope
of the disclosure. Thus, for a claim that recites a structure that
deflects and spreads kinetic energy, the structure could apply in
any application disclosed herein (vehicle, helmet, body armor,
building protection, etc.) as well as other structures not listed.
Those skilled in the art will readily recognize various
modifications and changes that may be made to the principles
described herein without following the example embodiments and
applications illustrated and described herein, and without
departing from the spirit and scope of the disclosure.
* * * * *