Cracking RC-member in bending

[StevenJS]

Hi all,

I'm working on a simulation of a reinforced concrete beam in bending.
It's a 2D-model, where i want to simulate the discrete cracking pattern of the beam in a 4-point bending test.

I created a cohesive zone model to describe the descrete cracking pattern.
However this model does not convergence when i'm trying to solve it in Abaqus (both static general and Risk solver).
Though the first 20% of the calculation that are completed give correct results (compared with experimental research: both the load-displacement graph and the cracking pattern are correct).

Now to improve convergence i was thinking of creating a dynamic explicit analyses since the high non-lineazrity of the problem.
However when running this dynamic analysis all kind of strange displacements occur in my model, which are obvious not correct, see the image below.
Does anyone know why changing my solver to the dynamic explicit causes these weird displacements?

Thanks in advance for any help!

 

[StevenJS]

The image in the post above doesn't seem to work.

These displacements are occuring when using dynamic explicit analysis

 

[IceBreakerSours]

Change the deformation scale factor to 1.

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[StevenJS]

I used a deformation scale factor of 75 to show what is actually happening.
The model consist of a 4-point bending test, where only half of it is moddeld (to save computation time), the symetrie axis is on the right.
The beam is supported on the left, and the displacement is placed on a steel block on top (the displacements is pointing down).

Thus there is no reason why cracking of the concrete can occur over the full heigth of the beam (so in the compression zone as well!)
And also on the left of the model, where large deformations and cracks are occuring, no cracking is expected.

Changing the deformation scale factor only influences the visual output.
I only used this, to show what is actually happening in the model.


I can post an image with a deformation scale factor of 1 as well.
But you are not able to see what is actually going on.