Hello,

I am doing cyclic quasi-static simulations in Abaqus. In order to overcome nonlinear material issues I am using Abaqus/Explicit. For definition of loading history for applied displacement (displacement controlled test), amplitude definition of type SMOOTH STEP is defined. I made quite a lot of such simulation obtaining very good results. However there is a problem I encountered:

after several cycles amplitude values imposed by Abaqus start to differ with those defined in the input file.

I am not sure now if the SMOOTH STEP amplitude definition is suitable for such a purpose: I defined all the cycles in one STEP with STEP TIME option for definition of the amplitude (all defined cycles are performed in one single step).

I found it more interesting, when I tried to speed up the simulation - from quasi-static to "dynamic" one. Namely, in the latter case the amplitudes imposed perfectly match the values defined in the input file, see the attached diagram.

Is the problem in loading speed? As far I know, SMOOTH STEP amplitude definition is used for quasi-static analysis in order to produce "smooth" response.

I would like to clear this topic to myself, since I am working on the study that has to be finished soon.

Thank you for your help in advance.

Blaz