  Fractional order models have proven to be a very useful tool for the modeling
of the mechanical behaviour of viscoelastic materials. Traditional numerical
solution methods exhibit various undesired properties due to the non-locality
of the fractional differential operators, in particular regarding the high
computational complexity and the high memory requirements. The infinite state
representation is an approach on which one can base numerical methods that
overcome these obstacles. Such algorithms contain a number of parameters that
influence the final result in nontrivial ways. Based on numerical experiments,
we initiate a study leading to good choices of these parameters.
