MAT/LAW 21 (DPRAG)

Nancy Jewel Mcdonie

Hi all, 

Can anyone explain for me what is F in this equation? I'm modeling sand material use MAT LAW 21. 

Polyvios Romanidis

Hi Nancy,

This F parameter is set in order to define the yield point.  The following is true for your material based on F value:

• F = 0, material exactly at yield point
• F > 0, material in the plastic region
• F < 0, material in the elastic region

This parameter can also be used for Von-Mises yield criteria, where the pressure-dependent terms are equal to 0 and A0 = yield point.  This can probably help you to better understand the use of this value.

Polyvios