Static Optimization and Ligament Object

[Ryan Bakker]

Has anybody been able to run Static Optimization with a ligament object in their model? I can run CMC just fine but SO does not run. The fact that CMC runs indicates to me that the ligament is implemented correctly.

Thank you
-Ryan Bakker

[Ryan Bakker]

I have also tried to add multiple types of springs instead of a ligament, but I end up with the same crash.

-Ryan

[Ayman Habib]

Hi,

Since this's reported as crash, can you please file a bug report and attach all the necessary files to reproduce it so that we can investigate, propose workaround or solution?

Thanks much,
-Ayman

[Joe Prinold]

I have had a similar problem to this.

When I run static optimization on a lower limb model (without any ligaments) or CMC on the same lower limb model (without any ligaments or with a single ligament) it runs with no problem. However, when I run static optimization on the lower limb model (with the same single ligament) it takes a very long time to solve - in fact it seems to just hang, I haven't been able to reach a solution.

The other concerning thing is that the constraint is quite significantly violated in the static optimization (with a single ligament) even though the ligament has a very long rest length (1m) and so should be slack during the whole trial.

Any help would be appreciated. The model files, motion files and set-up files are attached.

Joe