Abaqus - Question about DEM

Dear all,


I am trying to simulate a simple powder compaction process using DEM and I wanted to ask, is it possibe to use Probability Density Function type=Discrete in order to have different particle sizes (similar to particle generation methode) from the begining? 


PS: I have already added a PDF to my input file and replaced its name with the radius of the particles and I received this error: The total model mass is zero. Check the specifiedmodel mass including the rigid bodies.


I am looking forward to receiving some help.

Regards,

Erfan

Abaqus ​​​​​​​