The way I understand SOL400 works with inertia relief is you must add that case control command (IRLOAD=QLINEAR) and you can define a set of statically determinate constraints (and only statically determinate- just enough to remove all possible rigid body motion). These constraint DOF will become the reference DOF for the inertia relief solution.
Look at the Inertia Relief section in the Linear Static Analysis User Guide to see how to define appropriate 'SUPORT' DOF... these are the same rules you should follow when defining the 'constraints' for SOL400 with IRLOAD=QLINEAR turned on.
If you make a sample you can share, and you can't get it to work, please open a support case and mention my name and I'll help out.
Also, I have just done a test, and in v2019, and it looks like it worked fine... it is attached. Check out the SPCFORCE results to see that there aren't really any forces, so it isn't 'really' constrained.
The way I understand SOL400 works with inertia relief is you must add that case control command (IRLOAD=QLINEAR) and you can define a set of statically determinate constraints (and only statically determinate- just enough to remove all possible rigid body motion). These constraint DOF will become the reference DOF for the inertia relief solution.
Look at the Inertia Relief section in the Linear Static Analysis User Guide to see how to define appropriate 'SUPORT' DOF... these are the same rules you should follow when defining the 'constraints' for SOL400 with IRLOAD=QLINEAR turned on.
If you make a sample you can share, and you can't get it to work, please open a support case and mention my name and I'll help out.
Also, I have just done a test, and in v2019, and it looks like it worked fine... it is attached. Check out the SPCFORCE results to see that there aren't really any forces, so it isn't 'really' constrained.
