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How to analyse those force curves from a balistc impact

Hello ,

In order to study a balistic impact between a metallic shell and a rigid ball , I realize different simulations with different constitutive law :

1)J-C1 ( plastic strain =0,1,Shell thickness= 1mm )

2)J-C2( plastic strain =1E30 ,Shell thickness= 1mm )

3)J-C 2( plastic strain =1E30 ,Shell thickness= 5mm)

4) elastic law (Shell thickness= 1mm)

I plot the normal force to estimate the impact force for each simulation but the curves that i obtained seems wrong and i am not able to analyse the force curves .

Thanks for helping

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Altair Forum User

Hi,

Can you please share one model file of these (for eg: J-C 2( plastic strain =1E30 ,Shell thickness= 5mm) model file, with h3d and T01 file), so that we can review the same.

Altair Forum User

Hello ,

Here is the model as you requested .Normally i should obtain a minimmum curve that correpond to the elastic beahviour because there is no plastic starin to absorb the kinetic energy , but here ,it's not the case , it shows clearly that the absorbed energy is huge when the plate is elastic . Then i want to be sure that plotting 'normal force' is corresponding to' imapct force '

Thank you in advance

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Altair Forum User

Hi,

I just reviewed the time history curves for elastic and elasto-plastic materials.

The global energy curves looks fine. For elastic materials the Internal Energy (IE) curve will rise and will go down as a typical pattern and the same is happening here. Whereas for elasto-plastic materials the IE curve will rise and will hold that energy. In this case the curve pattern is fine. But as you said for elasto plastic materials we expect more energy absorption. The possible reason in this case will be the material values you have provided, that is the a and b values. Based on this the material will behave.I recommend you to recheck the same.

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