Hello
A reason for the damping of your system could be the numerical damping in ASE. Please have a look at this post from last year.
Further information about damping can be found within the DYNA Manual.
SSD / TEDDY > Help > User Manuals > All Manuals… > dyna > chapter 3.11 MODD - Modal Damping
SSD / TEDDY > Help > User Manuals > All Manuals… > dyna > chapter 3.5 GRP - Selection of Element Groups
And you could have a look at the related dyna examples.
TEDDY > File > Examples > dyna > english > …
TEDDY > File > Examples > ase > english > dynamics > …
Best regards
Frederik Höller
Your SOFiSTiK Support Team