Learning Forum

[linjun]

I am making a FE model of composite by the mat 58 bulit in ls-dyna. In the newest version in ls-dyna r13 and r14, the 3d solid element has been accepted to use mat58, however, few informations about  3d equaiton of mat58  can be find, it seem that at present only the 2d equation of mat 58 are introduced in the manual. Can angbody provied more information?

[Pedram Samadian]

Hello,

Can you please clarify what information you are looking for about the support of solid elements in *MAT58? 

*MAT58 with the “SOLID” option work for solid elements. Details about this material card can be found in LS-DYNA Keyword User’s Manual Vol. II (LS-DYNA Materials Manual) and Theory Manual (LS-DYNA Theory Manual).

I would also suggest using the latest LS-DYNA solver (R15.0.2), which can be download at LS-DYNA (user=user) Download Page (username: user & password: computer).

Thanks,

Pedram

 

[linjun]

Hello, is there a similar three-dimensional formula, something like this, all the information so far is only two-dimensional equations.

[Pedram Samadian]

Hi,

Are you looking for the tensorial form of the stress-strain relationship in this material card? Something like Sigma = C : EPS with the stiffness matrix components C for orthotropic materials?

Pedram

 

[linjun]

Dear Pedram, you're right. I'm looking for this stiffness matrix. Do you have any relevant information?

[Pedram Samadian]

Hi,

The stiffness matrix for orthropic materials is as below:

Was this what you were looking for?

Pedram

[linjun]

Thank you so muach!!!!

These components can help me better understand the operation mechanism. Thank you again!

[linjun]

Dear Pedram, I have encountered a new problem in understanding MAT58 model, and I would like to ask you about it.
The specific problem is: I'm modeling the through-thickness direction bending, but there seem to be too many parameters. For example, EPSF EPSR, TSMD GM23, GM31, TAU2, GAMMA2, TAU3, GAMMUA3. Do I have to enter all these parameters?
I tried a few things, input TAU23(31 also),GAMMA23 (31),GM23(31) and SC23(31) can simulate a suitable curve, but I'm not sure if I need EPSF,EPSR,TSMD.
Thank you very much for your patient answer

[Pedram Samadian]

Hi Linjun,

You do not have to put any values for those 3 parameters based on the samples I have. Have you run the model to see if LS-DYNA gives you an error? By the way, the TSMD has a default value of 0.9. If you are not sure what value to be given to it, leave the default value there.

Thanks,

Pedram

[linjun]

Thank you very much for your advice. Now I have not entered these three parameters, and the model still works well. It seems that the values TAU2,GAMMA2, SC23,GM23 replace the original EPSF,EPSR,TSMD.

Lin

[Pedram Samadian]

Great. Thanks for the update.

Pedram