concrete damaged plasticity model-errors 1

[Francis666]

https://files.engineering.com/getfi...58c2-4c7e-b270-a2cea99e44b2&file=cdp23.02.cae

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Hello guys. My friend modelled a reinforced concrete beam. Problems faced are The plasticity/creep/connector friction algorithm did not converge at x points in ABAQUS. I edit step but problem persists and job is aborted.
She also defined a boundary condition which is pinned. and also a displacement (-50mm) as she wants crack stop at 50mm.
a)Should she use a xfem crack method to correct the model to so that crack stop grow at 50mm?
or what correction can be made? for example, to boundary condition
b)visualisation from aborted job only shows beam, but stirrup and steel are missing and there is no crack and beam no moves downward. Should she insert loading?
c) what are some ways i can control growth of crack at the beam?
May i have someone gives suggestion/ checking model? Urgent. Thanks for opinions, guys.

 

[FEA way]

To eliminate this warning about plasticity algorithm convergence try the following:
- increase mesh density and make sure that there’s no hourglassing (plot ALLAE vs ALLIE to check that)
- reduce initial time increment
- enable stabilization in step settings but make sure that it doesn’t influence the results (plot ALLSD vs ALLIE to check that)
- try using different boundary conditions or replace them with rigid rollers like those used in real life 4-point bending test

XFEM can be used with CDP to model crack propagation, it’s a good idea. But first make sure that the model without XFEM works properly because introduction of XFEM will introduce yet another source of high nonlinearity and may cause problems. Another way to visualize cracking patterns in a model without XFEM is to use symbol plot of PE, Max Principal.

Reinforcement can be visualized when you remove beam instance from viewport using display group options. Deformation will be visible when you increase its scale factor in common plot options.

Cracks propagate according to specified damage criterion. Adjust it to control the propagation of cracks.