Questions on Radioss NLGEOM Solver

Hello,

I have a few questions on the Radioss NLGEOM solution. The model file is attached (please rename from jpg to hm):

1) When there are multiple subcases e.g. loading and unloading of a structure, it happens that I can not choose the second subcase in HyperGraph Postprocessing. An error message occurs. Is there a way to prevent this error message?

2) The process to define the loading / unloading sequence of a structure is described in Radioss Tutorial RD-2100. It is described to uncheck the LOAD entry for the second (unloading) subcase. However if I do this for my model, there is no connection between the loading and unloading sequence in the Hypergraph stress-strain curve. How do I need to define the unloading sequence correctly?

3) When using MATS1 with Hardening Modell 3 (70% isotropic und 30% kinematic Hardening), Material curve via TABLES1, Total Strain Curve, I see a good correlation to the tested prove for the loading sequence of my model. However the unloading sequence does not have a good correlation. Do you have any hints and tipps, e.g. to define a different Material Law or to change my loadcases, in order to reach a better correlation to the test curve (blue is the test and red the simulation curve)?