Run time is an important consideration. With 3D tet meshes of solids
easily exceeding 1 million dof memory can sometimes become a
consideration. As soon as anything non-linear is added, be it gaps,
inplane stress stiffening, or transient thermal analysis run time can
greatly increase. One of the advantages of the higher end systems is
that they allow hex meshing (using brick or rectangular elements) and
using simplified elements like shells, plates, and beams. More skill is
required in setup, but run time is greatly reduced and sometimes
accuracy can actually be improved.
I have on occasion run jobs that took over 60 hours to converge (or
not) on a fast PC. Run of the mill is an hour. Quicky jobs run in a few
minutes. So separating the CAD side from the solver side and resetting
task priority is a big time saver even on a single processor machine.
Take this model for example:
To do this in CosmosWorks might be possible, but in Cosmos/M it was
quite easy and it was certain it was going to work before the project
was started. What you are looking at is a four bar linkage with over
center spring and a lever which contacts the joint in the four bar. It
runs really fast and took an hour to build and get running. In the
generalize line type gap elements
The model is driven by an enforced displacement.