Abaqus explicit-Unexpected output results

[MrusTgr88]

Hello everyone,



I made simple cantilever model in Abaqus/Explicit. For concrete I have used Concrete damaged plasticity model and for reinforcement I have tried two models (one with Truss and second with Beam elements). I have assigned displacement as BC (Smooth amplitude) in Reference Point at the end of the beam, and I have coupled RP with the end of the beam. For concrete beam I have used C3D8R elements.

For history output I have requested Reaction force in RP and energies for whole model.

But results I am getting aren't expected.

I am sending you pictures of Reaction Force and ALLAE, ALLIE and ALLKE. You can see that results after 6.2s aren't good.



Can anyone tell me why and give me some suggestions?

Thanks

 

[MrusTgr88]

Kinetic energy

 

[MrusTgr88]

Internal energy

 

[MrusTgr88]

Artificial energy

 

[OrlandoTaddeo87]

I got problems similar to yours.

I can't obtain a reasonable force vs displacement curve with reinforced concrete elements.
Moreover, even increasing the lenght of the step time, the kinetic energy is "jagged", because it dosn't vary smoothly during time.

Even on this forum, I couldn't find any help.
Have you found some suggestions in these months? I've seen that the post is quite old.

I'm sorry for answering to your post with other questions, but I've been "fighting" with this problem for almost one month, and I didn't find a solution.


Thank you,
Orlando

 

[MrusTgr88]

Hi Orlando,

unfortunately I haven't find the right answer.

I think that maybe it is answer in reinforcement or something related to finite elements definition. Because I have tried to model the RC frame. I have used truss for reinforcement and embedded constraint. And also CDP for concrete. But the job wont finish. It stops at 0.8-0.95s. And the step time is 1s. I have tried with 10s step, with mass scaling, with different ways of appling the load but I can not find the solution.

What is your problem. What have you tried?

Best,
Marko