Learning Forum

[Rong Jin]

What is the difference between *EOS_004 (EOS_GRUNEISEN) and *EOS_016 (*EOS_MIE_GRUNEISEN) ? Do the two EOS represent the same EOS? If I would like to describe the relationship between pressure, volume and internal energy, which EOS will be better to use?

 

[mohan.urs]

Hello, Rong Jin

Both EOS-004 and EOS_016 have similarities and originate from the whole Mie-Grüneisen equation of state. The link between pressure, volume, and energy is explained by both of them.

While EOS_004 explains how the vibrational characteristics and particle velocity of a crystal lattice can alter its volume, EOS_016—a particular variant of the Gruneisen equation—is specifically utilized for high pressure shock compressions.

Regarding the relationship between pressure, volume, and internal energy in your question, both are relevant, but as I've already mentioned, it relies on the pressure circumstances in your setup.

More details about the actual equations can be found in Volume II of the LS-DYNA Keyword Users Manual.

Thanks

Mohan Urs