8,8 cm PzGr 39 Performance

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Tenkist
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Posts: 18
Joined: 19 Jan 2018, 00:22
Location: Poland

Re: 8,8 cm PzGr 39 Performance

#196

Post by Tenkist » 11 Sep 2022, 00:23

Timber wrote:
28 Aug 2022, 01:14
Tenkist wrote:
10 Aug 2021, 19:06
Mobius wrote:
31 Jul 2021, 17:17
Here is an interesting simulation of the 88mm.
https://www.youtube.com/watch?v=WVvA6TYXMLI
Some people use professional software like a toy. This simulation has nothing to do with reality and the creator has no basic knowledge in this area. If you want to find simulations that have something to do with reality, only here.

https://www.youtube.com/watch?v=76IBfPHFtUU
Don't see it as any more toy'ish than Djemian XYZ's videos tbh. Both creators are just plugging in figures to generate what'ever results they think look right.

Djemian has some pretty laughably unrealistic videos on 7.5 and 8.8cm PzGr.39 that are easily debunked by simple comparison with rl test results as well.
Do you have any knowledge of metal behavior at high strain rates? Rather not, since you don't see the difference. Equating these two simulations just because your numbers don't match is an extremely primitive approach to a very complex subject. You can distinguish several signs of proper metal behavior and it was perfectly shown in few videos (simulation vs reality) so the models work, a question of thousands of hours of testing to adjust the parameters... but 99% of people don't know gold from crap, so there's no point in wasting hundreds of hours getting parameters because no one will appreciate it anyway.

critical mass
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Posts: 740
Joined: 13 Jun 2017, 15:53
Location: central Europe

Re: 8,8 cm PzGr 39 Performance

#197

Post by critical mass » 16 Sep 2022, 12:49

I think everything can be made in finite element simulations to match the results. There are plenty of variables. The correct way of using these tools is not to run a simulation and take the results at face value but to controll the unknown variables and repeat simulations on known data samples so that You can get a better understanding about which set of variables have what sensitivity on the posterior result. That way, we may not arrive at prognosis but we can rule out unreasonable assumptions. Fine for me.


Peasant
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Posts: 798
Joined: 16 Oct 2018, 18:21
Location: Ukraine

Re: 8,8 cm PzGr 39 Performance

#198

Post by Peasant » 20 Apr 2023, 19:54

Here is some testing done by the soviets on captured german long 88mm. The results at 0° look about as expected, but it is interesting to see that the 8.8cm PzGr.39 is having some trouble with 150mm/30° target.

Image
8,8cm monobloc Pzgr 39/43
Plate thickness: 160mm RHA (1944 amended to 180mm RHA)
tensile strength: 90kg/mm² +- 5kg/mm² (1944 amended to 80-90kg/mm²)
obliquity: 30°
velocity: 900m/s (1944 amended to 950m/s)

demands on the projectile:
impact toughness at base: lengthwise: >8 mkg/mm² but no less than 6 mkg/mm², perpendicular: no less than 4mkg/mm²
Rc hardness: ideal Rc59 at nose (outside and Rc56 in centre), less than RC55 encountered anywhere at nose and lot will not be passed to ballistic test.
2 shots. If both penetrate intact, lot passes(A). If one fails, another projectile from the lot is retested and lot only passed if that projectile penetrates intact(b). Else, lot is rejected.
= (A) 2 out of 2 or (B) 2 out of 3 successes in intact bursting condition (projectile damage does not reach cavity or fuze adaptor)

Notice: Officially rated performance was 165mm RHA at 30° and 900m/s and 180mm RHA at 940m/s for the Pzgr 39/43.
viewtopic.php?f=47&t=231147
Note: 90kg/mm² +- 5kg/mm² equals to 250 - 279BHN.

This chart here shows the ballistic limit for 150mm/30° as ~860m/s:

Image

Thoddy
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Posts: 200
Joined: 18 Jun 2017, 12:37
Location: Germany

Re: 8,8 cm PzGr 39 Performance

#199

Post by Thoddy » 22 Apr 2023, 10:06

Any unusual conditions mentioned?
-What date was this test.
-manfacturing date of projectile (manufacturer stamp)
-labeling of projectile
-Abnormal testing temperatures
-Weight of projectile
-Condition of projectilepast penetration

... maybe an older heat treatment or manufacturer with less experience (for Bochumer Verein, Skoda, Freital i would exclude quality problems... Krupp maybe... other more probable)
"Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!"

Peasant
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Posts: 798
Joined: 16 Oct 2018, 18:21
Location: Ukraine

Re: 8,8 cm PzGr 39 Performance

#200

Post by Peasant » 22 Apr 2023, 10:41

Thoddy wrote:
22 Apr 2023, 10:06
Any unusual conditions mentioned?
-What date was this test.
-manfacturing date of projectile (manufacturer stamp)
-labeling of projectile
-Abnormal testing temperatures
-Weight of projectile
-Condition of projectilepast penetration

... maybe an older heat treatment or manufacturer with less experience (for Bochumer Verein, Skoda, Freital i would exclude quality problems... Krupp maybe... other more probable)
There is no information of this kind in the report. It presents a summary of the results obtained elsewhere at some unknown point in time. It's dated 1946 (no exact date), Leningrad, NII-48(Nauchno-Issledovatel'skij Institut/Research and Development Institute No.48). Weight of the 88mm shell is listed a 10,16kg.

Thoddy
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Posts: 200
Joined: 18 Jun 2017, 12:37
Location: Germany

Re: 8,8 cm PzGr 39 Performance

#201

Post by Thoddy » 25 Apr 2023, 13:48

In my opinion , because of the absence of any meaningful data regarding composition of projectile steel and hardnessprofile/heat-treatment of the projectiles and projectile constitution after the test, the results of these tests appeared as inconclusive/invalid to describe typical performance of up to date 8,8 cm armour piercing shells.

Most likely tip/core strenght of the tested projectilee were to low, so that the projectile at least deformed badly during the penetration process.

I can only speculate, that these projectiles used for the test were decommisioned projectiles from a arsenal, for use as a last workaround, if "approved" projectiles were not available.
"Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!"

Peasant
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Posts: 798
Joined: 16 Oct 2018, 18:21
Location: Ukraine

Re: 8,8 cm PzGr 39 Performance

#202

Post by Peasant » 18 Sep 2023, 21:32

Image

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