hcs modeling in Abaqus

[Ilinca Moldovan]

Hello there,

I am modelling a hollow core slab in Abaqus and the results obtained do not completely fit the ones from the experimental tests.That's why I am writing here,maybe someone can give me a new hint.
I have modelled the concrete using the CDP material behaviour(and also included the damage parameters both for compression and tension) and the prestressing tendons with plastic behaviour.I defined prestress with predefined field,in the initial step,then in the following step(static general) I introduced gravity for the whole model and in the last step(static riks) I used the displacement control analysis.The failure load matches the value obtained in the tests,but my model in Abaqus does not have a yield plateau like the one in the test.I have tried all the posibilities I could think of, and still it does not look perfect.
Has anyone dealt with a situation like mine?If so,please give me a hint so I can improve my model in Abaqus.

Thanks in advance,

Ilinca

 

[FEA way]

Can you share a picture showing your model and provide more information about it ? Also please attach these plots that you are talking about (experimental vs numerical results).

 

[Ilinca Moldovan]

I used C3D8 for concrete,T3D2 for the tendons.
For the supports I defined separate parts with discrete rigid and used then interaction(master-slave surfaces).The BC for the supports are defined in the reference points I created on each surface of the supports.
In the experimental test the load was a concentrated one and applied on the upper part of the hcs.In Abaqus,I defined a discrete rigid surface and imposed then a displacement in the last step of my analysis(static riks).