LSDYNA 971 update

[EvanD]

I have a simulation which uses mat model 77, an ogden rubber model. It runs fine in lsdyna 970, but after updating to 971, the min timestep becomes much smaller (0.585E-05 goes to 0.429E-07) and I get negative volume elements. Looking at the release notes for 971,

http://www.cadfem.de/fileadmin/files/lsdyna/website/pdf/pdf_release_update/ReleaseNotes-Ver971.pdf

there's no statement about a change to that material model.

Does anyone know what might be the cause of this?

Thanks in advance,
Evan

 

[lubos38]

Helo Evan

In LS-Dyna is still alchemy, I recomended to you use a internal solid contact and sometimes help stiffer Young modul in material deffinition for crash parts as well. You ve got problem with contact stiffnes, it doesnt have to do with material stifness.
Regards Lubos