Impact Analysis

proudbrown

Hi,

 

I am new to HyperWorks.

 

I did a 2 simulation trials for impact using same mesh model, same velocity but with different mass and it gives me same results.

The crack propagation came exactly at the same time frame.

I was expecting that the lower mass will not give me cracks as compared to the higher mass load.

What am I missing here? Does mass have effect if we are using velocity?

 

I used HyperMesh and RADIOSS.

 

thanks,

 

 

Altair Forum User

Hi Irwin,

Since you have provided the same velocity the impact time will be same for both the components. But the damage/crack occurred may be less for the component with no mass compared to the component with higher mass. If you plot the energy plots using T01 file you can notice the difference in KE for both the components (since KE=1/2 mv2).

 

proudbrown

Hi George,

 

thanks for your reply.

i was expecting that the lower the mass, damage should be also less and cracks may not occur since i used only half of the mass from my initial analysis.

but the damage/cracks are just the same and occurred in the same time frame.

is there anything i need to change in the parameters?

 

Altair Forum User

Hi,

Can you please let me know which damage card you have used for crack failure simulation?.

Also, please plot the energy curves (Internal Energy, Kinetic Energy and Total Energy)  in HyperGraph for both the cases and please upload a snapshot of it.

proudbrown

I used Fail Johnson card.

 

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Altair Forum User

Hi,

You can notice the difference of kinetic energy in both the cases, which is due to the difference of mass in both the models.

Based on the damage parameters the crack/damage is happening in the model and it seems like the material reaches the rupture criteria very easily after an impact with a body of no mass.

proudbrown

Does it has something to do with the damage parameters? or settings in properties?

Altair Forum User

Hi,

From the above plots the energy absorbed (internal energy curve) for both the cases seems same. It seems like the rupture parameters are easily reached on both the cases and so you are not noticing any difference. You can try with different damage parameters. 

proudbrown

Thank you!