How to model preload + displacement

[FEAnalyst]

@ryantheengineer

If the preload causes a displacement of 1mm relative to the top of the sample, and I call for a 3mm displacement step afterward, the end result is a final displacement of 3mm only, rather than the 4mm I expect.

This is explained here: Understanding multistep analyses

If you don’t have plastic (permanent) deformation, the second step doesn’t take the deformation from the first step into account.

You could also export the deformed mesh from the first step and then use it to run second analysis.