How Accurate are the FEA Armor Penetration Simulations on Youtube?

[deees]

There are several content providers on Youtube posting terminal ballistic simulation videos, ex., SY Simulations, XDYN, Extreme Engineering Simulation, Dejmian XYZ.

 

The results of the modern APFSDS impacts on armor seem reasonable and certain illustrates why slopped armor is no longer useful.

 

Can anyone who actually knows this subject comment on the general accuracy or identify ones that are mostly correct, (without revealing privileged information?)

[stormrider_sp]

38 minutes ago, deees said:

There are several content providers on Youtube posting terminal ballistic simulation videos, ex., SY Simulations, XDYN, Extreme Engineering Simulation, Dejmian XYZ.

 

The results of the modern APFSDS impacts on armor seem reasonable and certain illustrates why slopped armor is no longer useful.

 

Can anyone who actually knows this subject comment on the general accuracy or identify ones that are mostly correct, (without revealing privileged information?)

Those softwares like Ansys and others can be very accurate, like most professional engineering simulation softwares nowadays. Nothing replaces real testing, but what using simulation does is shorten development times and costs. On the other hand, I disagree that sloped armor is not longer useful. The same mass of armor but not slopped will always perform worse. Also, slopped armor allows for better use of composites and/or reactive armor. One could simply use 150tons+ of steel and make an imprenatable tank, but it wont be very mobile. Sloped armor is just another feature among many in the unavoidable compromise between mobility, firepower and protection.

Edited July 16, 2021 by stormrider_sp

[deees]

26 minutes ago, stormrider_sp said:

Those softwares like Ansys and others can be very accurate, like most professional engineering simulation softwares nowadays. Nothing replaces real testing, but what using simulation does is shorten development times and costs.

I'm not questioning the accuracy of the FEA software, just whether it's likely that person configuring the simulation would be able to input the correct material properties to product meaningful solutions?

27 minutes ago, stormrider_sp said:

On the other hand, I disagree that sloped armor is not longer useful. 

I probably should have stated using highly-sloped armor for the purpose of deflecting modern long-rod penetrators is questionable. The penetrators don't defect significantly. The original Leopard 2 and Abrams being examples of armor designed after their introduction.

 

(The new front wedges and the Abrams hull above the driver are examples of highly sloped armor, but they defeat projectiles in different ways.) 

[Ssnake]

Opacity is my main beef with such simulations. The underlying math & models are usually solid. The question is, are the PARAMETERS for the model useful, and so far, I haven't spent much time on this, the parameters aren't fully disclosed.

 

So, the results "don't look obviously fishy", but I think that's all that can be said with a high degree of confidence.

 

 

What can be useful for understanding are comparisons such as the different telescopic rod designs, assuming that all runs were made with otherwise unchanges parameters.

[dejawolf]

On 7/16/2021 at 5:57 PM, deees said:

I'm not questioning the accuracy of the FEA software, just whether it's likely that person configuring the simulation would be able to input the correct material properties to product meaningful solutions?

I probably should have stated using highly-sloped armor for the purpose of deflecting modern long-rod penetrators is questionable. The penetrators don't defect significantly. The original Leopard 2 and Abrams being examples of armor designed after their introduction.

 

(The new front wedges and the Abrams hull above the driver are examples of highly sloped armor, but they defeat projectiles in different ways.) 

 

even if the slope doesn't deflect the round, it will still increase the LOS thickness of the armour. so an armour plate sloped at 60 degrees is effectively ~twice the LOS thickness. 

sloping ERA and NERA as well drastically increases the performance of these armours, as it allows them to act on the penetrator over a longer distance. 

[snakeShi*]

This is a good place to promote my channel. I can take questions on YouTube, but im rarely here.

 

 

[snakeShi*]

On 7/16/2021 at 12:03 PM, Ssnake said:

The question is, are the PARAMETERS for the model useful, and so far, I haven't spent much time on this, the parameters aren't fully disclosed.

 

I can't speak for the other artists, but I can confirm for myself that narrowing down the properties of each material to a realistic parameter is by far the biggest pain of my FEA's. RHA took me around 4 days, Tungsten Carbide - 1 week. Tungsten, a few days, Maraging Steel - about a week. Then there's creating near-perfect scale models in a CAD, importing them into the solver and confirming the mass values of each part match with historical values. Then replicating benchmarks based on historic values. God forbid you don't get a reasonable penetration at that point - then it's back to square one.

[Damian90]

On 7/16/2021 at 5:57 PM, deees said:

I'm not questioning the accuracy of the FEA software, just whether it's likely that person configuring the simulation would be able to input the correct material properties to product meaningful solutions?

I probably should have stated using highly-sloped armor for the purpose of deflecting modern long-rod penetrators is questionable. The penetrators don't defect significantly. The original Leopard 2 and Abrams being examples of armor designed after their introduction.

 

(The new front wedges and the Abrams hull above the driver are examples of highly sloped armor, but they defeat projectiles in different ways.) 

 

The problem with Abrams is that most likely it's upper glacis have changing thickness. Over driver compartment it's ~50mm thick, however over fuel tanks it might be thicker, perhaps ~80mm angled at 83 degrees.. We have photos that might confirm this theory, showing different thickness over glacis plate around driver hatch and above fuel tanks.

 

@Ssnake@dejawolf This is probably worth considering in the vehicle model in SB ProPE.

Also steel used, we might assume that two types of steel is used when building M1's. General structure is made from MIL-A-12560 steel with thickness ranging from 4.23mm to 152.4mm, hardness ranging from 363 to 400 BHN, yield strength 1187 MPa, tensile strenght 1318 MPa. While for specific parts and probably inside composite armor, MIL-A-46100 steel with thickness ranging from 2.5 to 50mm, hardness 477-534 BHN, yield strenght 1480 MPa and tensile strenght 1655 MPa.

[dejawolf]

the fuel tanks however are filled with self-sealing foam, which would explain their extra "thickness"

[F.T]

On 10/11/2021 at 8:18 AM, snakeShi* said:

 

I can't speak for the other artists, but I can confirm for myself that narrowing down the properties of each material to a realistic parameter is by far the biggest pain of my FEA's. RHA took me around 4 days, Tungsten Carbide - 1 week. Tungsten, a few days, Maraging Steel - about a week. Then there's creating near-perfect scale models in a CAD, importing them into the solver and confirming the mass values of each part match with historical values. Then replicating benchmarks based on historic values. God forbid you don't get a reasonable penetration at that point - then it's back to square one.

According to Dejmian XYZ, he modified the material model of the Explicit Dynamics module of ANSYS. However, I did not find any modification of the constitutive model relevant to the Explicit Dynamics in the ANSYS help document.

[P Lakowski]

Diesel fuel has been shown to exaggerated the yaw on long rod penetrators. besides i recall they had honeycomb construction.

Edited March 28, 2022 by P Lakowski