Learning Forum

[Youngjin Jeon]

In MAT 32, what density does the mass density (RO) use, glass or polymer?
Or should I write the average density of the two materials?

[Reno Genest]

 

 

Hello Youngjin,

Because there is only one density, I would put the overall density of the composite glass; that is, take the mass of the laminated glass (include all glass and polymer layers) and divide it by the volume of the laminated glass. Make sure that the mass of the laminated glass is correct at the end in your model. 

Note that *MAT_032 is an old way of modeling laminated glass. You could use *PART_COMPOSITE with shell elements and a material model for glass and also another material model for the polymer. Have a look at the LS-DYNA User Manual Vol I for more information on *PART_COMPOSITE:

https://lsdyna.ansys.com/manuals/

Here is more information from our knowledge database:

”Because mixing of different materials within a shell is quite easy with *part_composite, *mat_laminated_glass is almost obsolete except perhaps that it allows the glass to fail while the polymer remains intact and continues to stretch. Different material IDs and even different material types can now be combined in a single shell using the straightforward command *part_composite. This command can be substituted for *part, *section_shell, and *integration_shell. Glass and PVB would each have it’s own *mat data, e.g., mat_001 or mat_024. *Part_composite says which layer gets which material.”

Reno.

 

[Reno Genest]

Hello Youngjin,

You could also use *MAT_GLASS (*MAT_280) to model your laminated glass. You will find more information here:

Here is an example:

http://ftp.lstc.com/anonymous/outgoing/support/EXAMPLES/yaris_windshield_mat_280_pse.tgz

You will find more information on *MAT_280 in the user manual volume  II and here:

https://www.dynamore.de/de/download/papers/dynamore/de/download/papers/2016-ls-dyna-forum/Papers%202016/dienstag-11.10.16/materials-and-simulations/novel-approach-to-model-laminated-glass

https://www.dynalook.com/search?SearchableText=*MAT_280

https://www.dynalook.com/conferences/13th-european-ls-dyna-conference-2021/composites/tatarsky_arup.pdf/view

https://www.dynalook.com/conferences/13th-european-ls-dyna-conference-2021/crash/osnes_ntnu.pdf/view

 

Another approach would be to use peri-dynamics:

https://www.lstc-cmmg.org/peri-dynamics

You will find some example models and presentations here:

https://www.lstc-cmmg.org/ex-meshfree

You can download the paper by clicking on the number [1] and the input file by clicking on [in].

https://www.dynalook.com/conferences/11th-european-ls-dyna-conference/failure-miscellaneous/a-3d-discontinuous-galerkin-finite-element-method-with-the-bond-based-peridynamics-model-for-dynamic-brittle-failure-analysis/view

You can search for  "peridynamics" on dynalook.com for more papers.

 

/forum/forums/topic/windshield-glass-roof-material-modeling/

 

Let me know how it goes.

 

Reno.

[Youngjin Jeon]

Hello Reno

Thank you for your answer

I solved the problem

If there is another problem, I will ask again

Thank you

[Reno Genest]

Hello Youngjin,

Which solution did you use? This might help other users.

 

Thanks.

 

Reno.

[Youngjin Jeon]

Hello Reno.

I used the overall density of the  laminated glass you told me and it was close to the value I wanted.

I need to improve it more, but using the overall density was effective.

The rest of the solution is still under review.

[Reno Genest]

Hello Youngjin,

Sounds good. Thank you for the update.

Have a great day!

 

Reno.