Coulomb criterion for tangential spring and damping force?

Dear LIGGGHTS users,

From the LIGGGHTS-Manual I understand that the limitation of the tangential forces through the Coulomb criterion Ft = cof*Fn is applied only to the tangential spring force and not to the tangential damping force. For example in the documentation for the pair_style "gran" it says:

"The tangential overlap is truncated to fulfil F_t <= x_mu * F_n"

Or in the documentation for the model "tangential history" it says:

"The coefficient of friction cof is the upper limit of the tangential force through the Coulomb criterion Ft = cof*Fn, where Ft and Fn are the tangential spring and normal force components"

I understand this such that the spring overlap is truncated to fulfil the Coulomb criterion, while the damping term remains untouched. But when I look into the file "tangential_model_history.h", I, as an unexperienced C++ programmer, have the impression that the overall tangential force including the spring plus damping component is limited by the Coulomb criterion.

Could you perhaps clearify this to me? Thanks a lot!

Best wishes
Jens