Armor Penetration Calculator

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Brady
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Armor Penetration Calculator

#1

Post by Brady » 19 Sep 2020, 00:43

I am looking for and can't seam to find a tool to calculate the, or convert the values, from 30 degrees to Zero degreases.

Most references for instance will list penetration at 30 degrease, some at 0 degrees.

So What I after is a calculator that I can input the values and adjust the angle of impact and get the thickness penned as a result of that change.

I could of swore I used something like that in the past, I just cant find it now for some reason.


Thanks...

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Christian Ankerstjerne
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Re: Armor Penetration Calculator

#2

Post by Christian Ankerstjerne » 19 Sep 2020, 01:53

Brady wrote:
19 Sep 2020, 00:43
I am looking for and can't seam to find a tool to calculate the, or convert the values, from 30 degrees to Zero degreases.

Most references for instance will list penetration at 30 degrease, some at 0 degrees.

So What I after is a calculator that I can input the values and adjust the angle of impact and get the thickness penned as a result of that change.

I could of swore I used something like that in the past, I just cant find it now for some reason.


Thanks...
You can use my calculator:
https://panzerworld.com/relative-armor-calculator


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Mobius
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Re: Armor Penetration Calculator

#3

Post by Mobius » 19 Sep 2020, 02:15

You can use my naval armor and ballistics program.
http://www.panzer-war.com/Naab/NAAB2x.zip
Or my DeMarre program
http://panzer-war.com/Files/redstardemarre.zip

Brady
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Re: Armor Penetration Calculator

#4

Post by Brady » 19 Sep 2020, 05:32

Thanks for the Link's, and I am familiar with those, and they are Great tools to be sure, But , and color me thick, I cant see how to take the figures on the following chart and convert them to the values they would have for penetration if the angle of impact was "0" degrees:

Image

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Christian Ankerstjerne
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Re: Armor Penetration Calculator

#5

Post by Christian Ankerstjerne » 19 Sep 2020, 10:46

Brady wrote:
19 Sep 2020, 05:32
Thanks for the Link's, and I am familiar with those, and they are Great tools to be sure, But , and color me thick, I cant see how to take the figures on the following chart and convert them to the values they would have for penetration if the angle of impact was "0" degrees:
Gotcha. I updated the calculator to allow you to take this into account. Let me know if there's anything that's unclear.

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Re: Armor Penetration Calculator

#6

Post by critical mass » 19 Sep 2020, 15:47

There is little chance, a calculator can reproduce correct data for conversion 0° to 30°. This depends, among other things, on the state of the projectile and the specific failure mode, the target plate gives in.

F.e. the germans attributed a conversion factor in order of 1.23 if changing their reference 60° (=30° US definition, as they use 90° for perpendicular impact) to 90° (0° US) obliquity. However, it must be noted that this was only obtainable for the virtually indestructible Pzgr.39 (no change of shape whether it perforates or rebounds) striking their sort of RHA within velocities equalling 500 m/s to 1200 m/s for plates <2.3 to 3.4 cal/d (depending on projectile).

I suspect that soviet AP-HE and APBC-HE will have noticably reduced factors in this transition due to the projectile breaking up if the target plate >0.6 cal. But then again, they also tested their deformable shells vs higher hardness target plates, which will usually give in by a different failure mode.

I know that US APCBC-HE shells will break up at 30° if striking >0.9 cal softer RHA target plate but they are intact when striking 1.0 cal/D at 0°, so You have a zone of mixed results, depending on whether the projectile stays intact or breaks up.

British APCBC-shot will stay intact if the target plate does not exceed 1.5 cal in 30° from my data.

Its a can of worms in my opinion.

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Mobius
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Re: Armor Penetration Calculator

#7

Post by Mobius » 19 Sep 2020, 17:03

That 25mm gun has a bit of difference than the data I have.
25mm/L72 SA mle34 Antichar
Here's another calculator.
http://alternatewars.com/BBOW/Ballistic ... s_1-07.htm

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Re: Armor Penetration Calculator

#8

Post by Brady » 19 Sep 2020, 17:29

Ok, Thanks !

And this is what I came up, assuming I did this right these should be the approximate relative thicknesses ?

Image

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Re: Armor Penetration Calculator

#9

Post by Christian Ankerstjerne » 19 Sep 2020, 18:53

There is definitely more to armor penetration calculations that trigonometry. That said, the empirical data I have seen all point to real-world variations being far too great for any calculation to be anything other than approximations.

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Re: Armor Penetration Calculator

#10

Post by Brady » 19 Sep 2020, 18:57

Look at the pzgr 39 for instance, that would seam rather optimistic, that it could pen 68 mm of vertical plate, but then again I never really look at a reference for pen on a vertical plate.


That's Why I am wondering if I input the data correctly ?

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Re: Armor Penetration Calculator

#11

Post by Mobius » 19 Sep 2020, 19:36

Brady wrote:
19 Sep 2020, 18:57
Look at the pzgr 39 for instance, that would seam rather optimistic, that it could pen 68 mm of vertical plate, but then again I never really look at a reference for pen on a vertical plate.
That's Why I am wondering if I input the data correctly ?
That seems a bit high. I have 40mm @ 500m @ 0°. 50/50 But, that isn't calculated just normalized from actual data.

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Re: Armor Penetration Calculator

#12

Post by peeved » 19 Sep 2020, 20:06

German penetration data was usually for plate at 60 deg from horizontal; If the formula you are using excpects impact angles from the horizontal, then inputting 30 degs according to Anglo convention gives optimistic results. Try extrapolating penetration of vertical plate from 60 deg angle of impact results. Your 30 deg table matches German 60 deg results for 3,7 cm KwK at least, no PzGr 39 though in that calibre.

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Re: Armor Penetration Calculator

#13

Post by critical mass » 19 Sep 2020, 20:19

Christian Ankerstjerne wrote:
19 Sep 2020, 18:53
There are definitely more to armor penetration calculations that trigonometry. That said, the empirical data I have seen all point to real-world variations being far too great for any calculation to be anything other than guidance approximations.
I agree. In that specific context, that is 1940 reference frame, one would also need to point out that the Germans did not yet possess Pzgr.39 type quality service ammunition. The 5cm Pzgr.39 with welded on tip was yet to be introduced. I suppose the 5cm Pzgr gG was sufficient for the lowe rvelocities of the short 5cm KWK, though.

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Mobius
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Re: Armor Penetration Calculator

#14

Post by Mobius » 19 Sep 2020, 23:55

Mobius wrote:
19 Sep 2020, 19:36
Brady wrote:
19 Sep 2020, 18:57
Look at the pzgr 39 for instance, that would seam rather optimistic, that it could pen 68 mm of vertical plate, but then again I never really look at a reference for pen on a vertical plate.
That's Why I am wondering if I input the data correctly ?
That seems a bit high. I have 40mm @ 500m @ 0°. 50/50 But, that isn't calculated just normalized from actual data.
This has some penetration data but the gun data is different than what I have.
Attachments
25mmFrenchAntichar.jpg

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Re: Armor Penetration Calculator

#15

Post by Thoddy » 19 Sep 2020, 23:56

Comparison of calculated(de Marre, Krupp) and real performance using german 5 cm...8,8 cm
At 60 deg Auftreffwinkel=30 deg obliquity ;Report166 der Lilienthalgesellschaft
Screenshot_20200919-234929_Drive.jpg
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