Abaqus Damaged Plasticity- problem with Strain Rate
I am using Abaqus explicit to simulate a simple compression test on a concrete cube. The cube's bottom face is fixed, and the compression is given by giving a displacement to the top face. In order to simulate concrete material I'm using the damaged plasticity model.
From what I understand you can choose if you want the model to be strain dependent or not. My problem is that when choosing non dependent on strain rate I get different results for different speeds of loading. If on the other hand I do choose to make the model strain dependent then I get the same results (for a specific speed loads), even though the strain rates I choose are considerably different.
Does anyone have any suggestions? Any comments would be greatly appreciated.