Problem:

Model with 4 analysis sets has completely different displacement results:

Why? 

Solution:

There can be a number of reasons for this to occur. Start by looking at the any Analysis Warnings or Error messages that appeared:

Looking at the Analysis summary, see that remove lift-off support option was checked on for all analysis reports. Also note that different supports were removed based on Analysis Set settings.

Look at Analysis Set dialog. 

As a test, disable all "Remove Lift-off Supports" for all analysis sets, analyze the model and look at the results. 

Notice that all the GR load cases displacements for Analysis Set #1, #2, #3, and #4 now match.

Conclusion:

Always review analysis warning messages and understand what impact they may have on your analysis. 

Review your Analysis Set settings to understand that any differences in results may be directly related to changes between Analysis Sets. As a test, make all the options the same, analyze the model, and review results. If they are the same, then the reason for changes in results were directly related to the Analysis Sets. Otherwise contemplate other inputs that may be assinged to specific load cases, (ex. Concentrated forces, etc...).

See Also

Displacement report

Bentley AutoPIPE