Cant solve "too many attempts made for this increment"-issue on some models

Hello at all,

I have some serious issues with some of my models in Abaqus 6.14. I need to simulate shear failure to investigate the influence of concrete strength and fracture energy on the size effect. So far, everything went good. I calculated almost 100 models without any problem with exactly the same model (only materials changed). But: For the combination of concrete strength fck=50MPa and a fracture energy of Gf=60N/m or Gf=80N/m, the calculations will stop after a short time although the .odb file shows only some minor bending cracks in the beam

The weird part is, that as soon as I hit a fracture energy of Gf=100N/m to calculate the damage parameter and the residual tension strength everything will calculate as it is meant to do. So I guess, the model is not the source of my problem but Im not sure.

I use the concrete damaged plasticity model with a displacement-controlled load.

I googled the "too many attempts made for this increment"-Error and already set a tick for Nlgeom, turned "automatic stabilization" on, refined my mesh... every idea I found to solve this problem. Without success...

I'm no professional in abaqus. I am just doing the calculations for my thesis, so my knowledge is limited and I have no clue what to do...

I hope there is someone nice on this forum who has some experience with abaqus and could help me out!