How much pressure in an 800N touch?

[Bill MacLean]

I have wondered what an 800N hit actually means in terms of forces I can
understand. I have come up with one set of calculations. Please note, I am
not a physics guy. My background is in accounting and computer information
systems.



I appreciate any criticism, because I may be wrong:



1. 800N doesn't mean much to me, but I do have a an idea of how much effort
I would expend to resist a weight that was falling toward me under the
influence of gravity. I imagined myself lying on a weight bench with a bar
set up for bench press. So the question became: "How much would the bar
have to weigh to require that I exert 800N of force to keep the weight from
moving toward me?"



2. The acceleration of gravity is 32ft/second/second. In Europe you have
different gravity , so the metric acceleration of gravity is 9.8
meters/second/second.



3. One Newton is defined as the amount of force required to accelerate 1 kg
of of mass at the rate of one meter /second/second. A Newton is thus
1kg(meter/second/second)



3. Since Newtons represent kg * meter/second/second and the acceleration of
gravity is denominated in meters/second/second, it's easy to answer question
#1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a bar
that has 81.63kg on it, I have to exert 800N of force just to keep the bar
from moving down toward me. Of course, I don't have a gut feel for how
heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!



4. Things get pretty amazing when figuring the pressure on the tip resulting
from an 800N hit. The tip of a fencing weapon is quite small. I can't
speak to other weapons, but I measured my epee point at 1/4" diameter (about
6.35mm). The area of the circular tip is pi * r^2, where the circumflux
character means "raised to the power of ", and r = radius. Radius is
diameter divided by 2.



So here's the dope:

Radius of epee tip = 6.35mm / 2 = 3.175mm

Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm

r^ * pi = 10.08 * 3.1415927 = 31.67 square mm

Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm



Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665 lbs /
sq inch! That seems like a lot of pressure to me.



Can someone who is more qualified than me please review these calculations
and see if they make sense? If so, it's amazing to me what kind of
punishment the human body can take. Of course,



I don't know how many Newtons of force are involved in normal fencing hits.
I don't even know if it is possible for any athlete to generate an 800N hit.
Is there any recorded instance of a non-broken epee blade penetrating an FIE
rated jacket that was not defective?





Thanks,



Bill MacLean

[Trim Plus Expert]

Your calculation are good to a point, until the contact with the fencing
vest, 800N is for the resistance of the tissue fiber, however the point hit
squarely on it :

Sorry for the awfull diagrams

Blade I
-------------------- I Tissu
I
now a closeup of tissu fiber :
When
hit it wave like this :
_I_I_I_I_I_I_I_I_I_ I
_I_I_I_I_I_I_I_I_I_ Blade I
_I_I_I_I_I_I_I_I_I_ ---------------I
I I I I I I I I I
I

I

Now the 800N work in vector on 2 way

I I
Blade I I
---------------I Y
I l
I l
X ------l--
Now you have for X and force Y Y = 800N X=(on 30degre) 200N each side

you know that the tissu works 800N, but i am not sur how much degre the wave
is, you calculate some vector of force the blade versus the tissu stop then
you have a real force on the bare flesh, now the 800N work like a stopping
force not that 800N have to be stopped.





"Bill MacLean" <nospam@nospam.net> a écrit dans le message de
news:ESb4c.41287$h23.18888@fed1read06...
> I have wondered what an 800N hit actually means in terms of forces I can
> understand. I have come up with one set of calculations. Please note, I
am
> not a physics guy. My background is in accounting and computer
information
> systems.
>
>
>
> I appreciate any criticism, because I may be wrong:
>
>
>
> 1. 800N doesn't mean much to me, but I do have a an idea of how much
effort
> I would expend to resist a weight that was falling toward me under the
> influence of gravity. I imagined myself lying on a weight bench with a
bar
> set up for bench press. So the question became: "How much would the bar
> have to weigh to require that I exert 800N of force to keep the weight
from
> moving toward me?"
>
>
>
> 2. The acceleration of gravity is 32ft/second/second. In Europe you have
> different gravity , so the metric acceleration of gravity is 9.8
> meters/second/second.
>
>
>
> 3. One Newton is defined as the amount of force required to accelerate 1
kg
> of of mass at the rate of one meter /second/second. A Newton is thus
> 1kg(meter/second/second)
>
>
>
> 3. Since Newtons represent kg * meter/second/second and the acceleration
of
> gravity is denominated in meters/second/second, it's easy to answer
question
> #1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a
bar
> that has 81.63kg on it, I have to exert 800N of force just to keep the bar
> from moving down toward me. Of course, I don't have a gut feel for how
> heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!
>
>
>
> 4. Things get pretty amazing when figuring the pressure on the tip
resulting
> from an 800N hit. The tip of a fencing weapon is quite small. I can't
> speak to other weapons, but I measured my epee point at 1/4" diameter
(about
> 6.35mm). The area of the circular tip is pi * r^2, where the circumflux
> character means "raised to the power of ", and r = radius. Radius is
> diameter divided by 2.
>
>
>
> So here's the dope:
>
> Radius of epee tip = 6.35mm / 2 = 3.175mm
>
> Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm
>
> r^ * pi = 10.08 * 3.1415927 = 31.67 square mm
>
> Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm
>
>
>
> Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665 lbs
/
> sq inch! That seems like a lot of pressure to me.
>
>
>
> Can someone who is more qualified than me please review these calculations
> and see if they make sense? If so, it's amazing to me what kind of
> punishment the human body can take. Of course,
>
>
>
> I don't know how many Newtons of force are involved in normal fencing
hits.
> I don't even know if it is possible for any athlete to generate an 800N
hit.
> Is there any recorded instance of a non-broken epee blade penetrating an
FIE
> rated jacket that was not defective?
>
>
>
>
>
> Thanks,
>
>
>
> Bill MacLean
>
>
>
>

[Trim Plus Expert]

However its all a resistance force, and therefore its applied on the force
applied by the blade action/reaction principe the more you push against
something the more it push against you, up to the rupture point of the
tissu, however for a hit of an unbroken blade the force is more likely that
the tissu (more resistant than flesh) will act only in a stopping manner
like a soft bulletproof vest.

"Trim Plus Expert" <trimplus@bellnet.ca> a écrit dans le message de
news:nfj4c.48550$6y1.1637357@news20.bellglobal.com ...
> Your calculation are good to a point, until the contact with the fencing
> vest, 800N is for the resistance of the tissue fiber, however the point
hit
> squarely on it :
>
> Sorry for the awfull diagrams
>
> Blade I
> -------------------- I Tissu
> I
> now a closeup of tissu fiber :
>
When
> hit it wave like this :
> _I_I_I_I_I_I_I_I_I_ I
> _I_I_I_I_I_I_I_I_I_ Blade I
> _I_I_I_I_I_I_I_I_I_ ---------------I
> I I I I I I I I I
> I
>
> I
>
> Now the 800N work in vector on 2 way
>
> I I
> Blade I I
> ---------------I Y
> I l
> I l
> X ------l--
> Now you have for X and force Y Y = 800N X=(on 30degre) 200N each side
>
> you know that the tissu works 800N, but i am not sur how much degre the
wave
> is, you calculate some vector of force the blade versus the tissu stop
then
> you have a real force on the bare flesh, now the 800N work like a stopping
> force not that 800N have to be stopped.
>
>
>
>
>
> "Bill MacLean" <nospam@nospam.net> a écrit dans le message de
> news:ESb4c.41287$h23.18888@fed1read06...
> > I have wondered what an 800N hit actually means in terms of forces I can
> > understand. I have come up with one set of calculations. Please note, I
> am
> > not a physics guy. My background is in accounting and computer
> information
> > systems.
> >
> >
> >
> > I appreciate any criticism, because I may be wrong:
> >
> >
> >
> > 1. 800N doesn't mean much to me, but I do have a an idea of how much
> effort
> > I would expend to resist a weight that was falling toward me under the
> > influence of gravity. I imagined myself lying on a weight bench with a
> bar
> > set up for bench press. So the question became: "How much would the bar
> > have to weigh to require that I exert 800N of force to keep the weight
> from
> > moving toward me?"
> >
> >
> >
> > 2. The acceleration of gravity is 32ft/second/second. In Europe you
have
> > different gravity , so the metric acceleration of gravity is 9.8
> > meters/second/second.
> >
> >
> >
> > 3. One Newton is defined as the amount of force required to accelerate 1
> kg
> > of of mass at the rate of one meter /second/second. A Newton is thus
> > 1kg(meter/second/second)
> >
> >
> >
> > 3. Since Newtons represent kg * meter/second/second and the acceleration
> of
> > gravity is denominated in meters/second/second, it's easy to answer
> question
> > #1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a
> bar
> > that has 81.63kg on it, I have to exert 800N of force just to keep the
bar
> > from moving down toward me. Of course, I don't have a gut feel for how
> > heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!
> >
> >
> >
> > 4. Things get pretty amazing when figuring the pressure on the tip
> resulting
> > from an 800N hit. The tip of a fencing weapon is quite small. I can't
> > speak to other weapons, but I measured my epee point at 1/4" diameter
> (about
> > 6.35mm). The area of the circular tip is pi * r^2, where the circumflux
> > character means "raised to the power of ", and r = radius. Radius is
> > diameter divided by 2.
> >
> >
> >
> > So here's the dope:
> >
> > Radius of epee tip = 6.35mm / 2 = 3.175mm
> >
> > Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm
> >
> > r^ * pi = 10.08 * 3.1415927 = 31.67 square mm
> >
> > Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm
> >
> >
> >
> > Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665
lbs
> /
> > sq inch! That seems like a lot of pressure to me.
> >
> >
> >
> > Can someone who is more qualified than me please review these
calculations
> > and see if they make sense? If so, it's amazing to me what kind of
> > punishment the human body can take. Of course,
> >
> >
> >
> > I don't know how many Newtons of force are involved in normal fencing
> hits.
> > I don't even know if it is possible for any athlete to generate an 800N
> hit.
> > Is there any recorded instance of a non-broken epee blade penetrating an
> FIE
> > rated jacket that was not defective?
> >
> >
> >
> >
> >
> > Thanks,
> >
> >
> >
> > Bill MacLean
> >
> >
> >
> >
>
>

[Trim Plus Expert]

Wound test on meat proved it to rupture at 500 grams of pressure from a
sharp tip (and is the why foil point is set at 500g) , lets say a sharp tip
is about .2 square mm. So it rupture at 2.5kg/mm squa. Does it ring a bell
? 3555lbs/square inch


"Bill MacLean" <nospam@nospam.net> a écrit dans le message de
news:ESb4c.41287$h23.18888@fed1read06...
> I have wondered what an 800N hit actually means in terms of forces I can
> understand. I have come up with one set of calculations. Please note, I
am
> not a physics guy. My background is in accounting and computer
information
> systems.
>
>
>
> I appreciate any criticism, because I may be wrong:
>
>
>
> 1. 800N doesn't mean much to me, but I do have a an idea of how much
effort
> I would expend to resist a weight that was falling toward me under the
> influence of gravity. I imagined myself lying on a weight bench with a
bar
> set up for bench press. So the question became: "How much would the bar
> have to weigh to require that I exert 800N of force to keep the weight
from
> moving toward me?"
>
>
>
> 2. The acceleration of gravity is 32ft/second/second. In Europe you have
> different gravity , so the metric acceleration of gravity is 9.8
> meters/second/second.
>
>
>
> 3. One Newton is defined as the amount of force required to accelerate 1
kg
> of of mass at the rate of one meter /second/second. A Newton is thus
> 1kg(meter/second/second)
>
>
>
> 3. Since Newtons represent kg * meter/second/second and the acceleration
of
> gravity is denominated in meters/second/second, it's easy to answer
question
> #1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a
bar
> that has 81.63kg on it, I have to exert 800N of force just to keep the bar
> from moving down toward me. Of course, I don't have a gut feel for how
> heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!
>
>
>
> 4. Things get pretty amazing when figuring the pressure on the tip
resulting
> from an 800N hit. The tip of a fencing weapon is quite small. I can't
> speak to other weapons, but I measured my epee point at 1/4" diameter
(about
> 6.35mm). The area of the circular tip is pi * r^2, where the circumflux
> character means "raised to the power of ", and r = radius. Radius is
> diameter divided by 2.
>
>
>
> So here's the dope:
>
> Radius of epee tip = 6.35mm / 2 = 3.175mm
>
> Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm
>
> r^ * pi = 10.08 * 3.1415927 = 31.67 square mm
>
> Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm
>
>
>
> Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665 lbs
/
> sq inch! That seems like a lot of pressure to me.
>
>
>
> Can someone who is more qualified than me please review these calculations
> and see if they make sense? If so, it's amazing to me what kind of
> punishment the human body can take. Of course,
>
>
>
> I don't know how many Newtons of force are involved in normal fencing
hits.
> I don't even know if it is possible for any athlete to generate an 800N
hit.
> Is there any recorded instance of a non-broken epee blade penetrating an
FIE
> rated jacket that was not defective?
>
>
>
>
>
> Thanks,
>
>
>
> Bill MacLean
>
>
>
>

[Trim Plus Expert]

ho and lets say I can punch at 200lbs of pressure, if I put this on 0,049 sq
inch ( an epee tip) yes I could rip flesh (if the epee wouldn't bend) and an
average trainned guy can punch about his weight than on a bad hit (when the
epee don't bend) on a trainned athelete we need vests to lessen the power.
half the power would be just ok



"Bill MacLean" <nospam@nospam.net> a écrit dans le message de
news:ESb4c.41287$h23.18888@fed1read06...
> I have wondered what an 800N hit actually means in terms of forces I can
> understand. I have come up with one set of calculations. Please note, I
am
> not a physics guy. My background is in accounting and computer
information
> systems.
>
>
>
> I appreciate any criticism, because I may be wrong:
>
>
>
> 1. 800N doesn't mean much to me, but I do have a an idea of how much
effort
> I would expend to resist a weight that was falling toward me under the
> influence of gravity. I imagined myself lying on a weight bench with a
bar
> set up for bench press. So the question became: "How much would the bar
> have to weigh to require that I exert 800N of force to keep the weight
from
> moving toward me?"
>
>
>
> 2. The acceleration of gravity is 32ft/second/second. In Europe you have
> different gravity , so the metric acceleration of gravity is 9.8
> meters/second/second.
>
>
>
> 3. One Newton is defined as the amount of force required to accelerate 1
kg
> of of mass at the rate of one meter /second/second. A Newton is thus
> 1kg(meter/second/second)
>
>
>
> 3. Since Newtons represent kg * meter/second/second and the acceleration
of
> gravity is denominated in meters/second/second, it's easy to answer
question
> #1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a
bar
> that has 81.63kg on it, I have to exert 800N of force just to keep the bar
> from moving down toward me. Of course, I don't have a gut feel for how
> heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!
>
>
>
> 4. Things get pretty amazing when figuring the pressure on the tip
resulting
> from an 800N hit. The tip of a fencing weapon is quite small. I can't
> speak to other weapons, but I measured my epee point at 1/4" diameter
(about
> 6.35mm). The area of the circular tip is pi * r^2, where the circumflux
> character means "raised to the power of ", and r = radius. Radius is
> diameter divided by 2.
>
>
>
> So here's the dope:
>
> Radius of epee tip = 6.35mm / 2 = 3.175mm
>
> Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm
>
> r^ * pi = 10.08 * 3.1415927 = 31.67 square mm
>
> Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm
>
>
>
> Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665 lbs
/
> sq inch! That seems like a lot of pressure to me.
>
>
>
> Can someone who is more qualified than me please review these calculations
> and see if they make sense? If so, it's amazing to me what kind of
> punishment the human body can take. Of course,
>
>
>
> I don't know how many Newtons of force are involved in normal fencing
hits.
> I don't even know if it is possible for any athlete to generate an 800N
hit.
> Is there any recorded instance of a non-broken epee blade penetrating an
FIE
> rated jacket that was not defective?
>
>
>
>
>
> Thanks,
>
>
>
> Bill MacLean
>
>
>
>

[Trim Plus Expert]

Last, there is some difference between a sharp tip and a square one. A sharp
tip is gonna open organic tissu as soon as the right pressure is applied,
and a square one will compress/rip the tissu as it penetrate augmenting in
the process the resistance of the tissu.




"Trim Plus Expert" <trimplus@bellnet.ca> a écrit dans le message de
news:U3m4c.31486$hG.396575@news20.bellglobal.com.. .
> ho and lets say I can punch at 200lbs of pressure, if I put this on 0,049
sq
> inch ( an epee tip) yes I could rip flesh (if the epee wouldn't bend) and
an
> average trainned guy can punch about his weight than on a bad hit (when
the
> epee don't bend) on a trainned athelete we need vests to lessen the power.
> half the power would be just ok
>
>
>
> "Bill MacLean" <nospam@nospam.net> a écrit dans le message de
> news:ESb4c.41287$h23.18888@fed1read06...
> > I have wondered what an 800N hit actually means in terms of forces I can
> > understand. I have come up with one set of calculations. Please note, I
> am
> > not a physics guy. My background is in accounting and computer
> information
> > systems.
> >
> >
> >
> > I appreciate any criticism, because I may be wrong:
> >
> >
> >
> > 1. 800N doesn't mean much to me, but I do have a an idea of how much
> effort
> > I would expend to resist a weight that was falling toward me under the
> > influence of gravity. I imagined myself lying on a weight bench with a
> bar
> > set up for bench press. So the question became: "How much would the bar
> > have to weigh to require that I exert 800N of force to keep the weight
> from
> > moving toward me?"
> >
> >
> >
> > 2. The acceleration of gravity is 32ft/second/second. In Europe you
have
> > different gravity , so the metric acceleration of gravity is 9.8
> > meters/second/second.
> >
> >
> >
> > 3. One Newton is defined as the amount of force required to accelerate 1
> kg
> > of of mass at the rate of one meter /second/second. A Newton is thus
> > 1kg(meter/second/second)
> >
> >
> >
> > 3. Since Newtons represent kg * meter/second/second and the acceleration
> of
> > gravity is denominated in meters/second/second, it's easy to answer
> question
> > #1. 800/9.8 = 81.63kg. That means if I am lying on a bench, pressing a
> bar
> > that has 81.63kg on it, I have to exert 800N of force just to keep the
bar
> > from moving down toward me. Of course, I don't have a gut feel for how
> > heavy an 81.63kg bar is, but I know that 179.59lbs is quite a bit!
> >
> >
> >
> > 4. Things get pretty amazing when figuring the pressure on the tip
> resulting
> > from an 800N hit. The tip of a fencing weapon is quite small. I can't
> > speak to other weapons, but I measured my epee point at 1/4" diameter
> (about
> > 6.35mm). The area of the circular tip is pi * r^2, where the circumflux
> > character means "raised to the power of ", and r = radius. Radius is
> > diameter divided by 2.
> >
> >
> >
> > So here's the dope:
> >
> > Radius of epee tip = 6.35mm / 2 = 3.175mm
> >
> > Radius ^ 2 = 3.175 x 3.175 = 10.08 square mm
> >
> > r^ * pi = 10.08 * 3.1415927 = 31.67 square mm
> >
> > Pressure = 81.63kg (from #3) / 31.67 sq mm = 2.578kg/sq mm
> >
> >
> >
> > Converted to English units, that's 179.59 lb / 0.049 sq inches = 3,665
lbs
> /
> > sq inch! That seems like a lot of pressure to me.
> >
> >
> >
> > Can someone who is more qualified than me please review these
calculations
> > and see if they make sense? If so, it's amazing to me what kind of
> > punishment the human body can take. Of course,
> >
> >
> >
> > I don't know how many Newtons of force are involved in normal fencing
> hits.
> > I don't even know if it is possible for any athlete to generate an 800N
> hit.
> > Is there any recorded instance of a non-broken epee blade penetrating an
> FIE
> > rated jacket that was not defective?
> >
> >
> >
> >
> >
> > Thanks,
> >
> >
> >
> > Bill MacLean
> >
> >
> >
> >
>
>

[Mark C. Orton]

On Thu, 11 Mar 2004 22:25:25 -0700, "Bill MacLean" <nospam@nospam.net>
wrote:

> I have wondered what an 800N hit actually means in terms of forces I can
> understand.

The rulebook has the specifications for how the test is performed.
(It's in Appendix A.)

The probe used has a 3 mm square cross section. The end of the probe
is pyramidal, with the sides of the pyramid set at an angle of 120
degrees. It moves at more than 6 m/s.

Since the end of the probe is pyramidal, not flat, the test is not
simply a measure of the tensile strength of the fabric; it also
measures how susceptible the threads are to being pushed apart by a
(somewhat) sharp point.

-Mark-