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Dynamic Explicit Impact Simulation and comparing with homogenized effective propertie

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Old   February 9, 2020, 11:19
Default Dynamic Explicit Impact Simulation and comparing with homogenized effective propertie
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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!
Attached Images
File Type: jpg homogenize_result.JPG (56.5 KB, 3 views)
File Type: jpg plate.JPG (75.7 KB, 3 views)
File Type: jpg Result.JPG (152.4 KB, 6 views)

Last edited by Jwes; February 9, 2020 at 21:58.
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Old   February 10, 2020, 08:01
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Is this because homogenization only gives the effective elastic properties and not the plastic properties?
Yep, you absolutely right. Look like your lattice collapsing is highly nonlinear process because of contact.
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Old   February 10, 2020, 08:09
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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!
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Old   February 10, 2020, 14:55
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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?
Yes, homogenous assumption is too coarse.
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