Dynamic Explicit Impact Simulation and comparing with homogenized effective propertie
 

Hi,

I am doing a simulation of a ball striking a plate that has a lattice structure within it. (See Plate.jpeg)

The results are shown in (Result.jpg)

I Then took a unit cell and brought it into ANSYS material designer to obtain the effective properties. These will give me the young's modulus (E1, E2, E3), shear modulus (G12, G13, G23) and 3 poison's ratio.

However, when I used these effective properties, my simulation result for the homogenized structure is vastly different. (see homogenize_result.Jpg)

Is this because homogenization only gives the effective elastic properties and not the plastic properties?

*I used the same plastic properties for the homogenized simulation as I did for the actual lattice impact simulation.

Thanks in advance!

Yep, you absolutely right. Look like your lattice collapsing is highly nonlinear process because of contact.

Thanks for replying karachun!

Just to clarify, thus means that homogenization will be quite useless for my scenario where i am looking into the possibility of plastuc deformation at different speeds?

The contact that i had for the ball and plate was tangential contact with penalty of 0.3 and normal contact at default values.

Thanks!

Yes, homogenous assumption is too coarse.