How does Nastran include structural damping (GEi) in PBUSH element into modal frequency response (SOL111)? Is it included as complex stiffness term?
For example structural damping GE in MAT1 card is added to the stiffness matrix as complex term.

Question

How does Nastran include structural damping (GEi) in PBUSH element into modal frequency response (SOL111)? Is it included as complex stiffness term? 
 
 For example structural damping GE in MAT1 card is added to the stiffness matrix as complex term.

Don.Graff · Accepted Answer

Yes, it is. The stiffness of CBUSH in Frequency Response is [K + i (K*ge)]. If anyone has another interpretation, I'll ask them to post, as well!

How does Nastran include structural damping (GEi) in PBUSH element into modal frequency response (SOL111)? Is it included as complex stiffness term? For example structural damping GE in MAT1 card is added to the stiffness matrix as complex term.