modelling of reinforced concrete cement block

gopal_rathore

Hi,

I m working on crash simulation which involves a reinforced concrete cement block at the foundation. Currently I have made a solid block for representing concrete and removed tmr rods solid part fomr it. Is this is the methodology or any other to be used?

In case of any reference file kindly share

I have attached the image of reinforced rods structure over which concrete will be poured.

Thank you

 

Altair Forum User

Hi Gopal,

This approach seems fine, ie represent with a solid concrete block.

I'll check internally for some references and if I get something related I'll share with you.

gopal_rathore

Hi @George P Johnson

I have made the solid concrete block and then removed the reinforced geometry from it This results in solid block with holes representing the surface of rods.

I am facing challenge in element size . As the rods are of two diameters i.e one i 12 mm and other is 20 mm. on selecting mesh size as 5 mm , the number of element count is going too high and hypermesh is getting crashed and on keeping 10 mm I am not able to capture rods with 10 mm dia

This Boolean option is enabling me to ensure node to node connectivity between rods and the concrete block but mesh size is creating problems

 

You have reference file for such modelling

gopal_rathore

Hi @George P Johnson

How to simulate failure and rupture of concrete modelled with mat law 24

Altair Forum User

Hi Gopal,

Which material law you are using for modelling concrete?.

If you are trying with Law24, you have an inbuilt failure criteria for this material model. Please go through the Help menu on this material law.

gopal_rathore

Hi,

I am working with MAT LAW 24 only. The failure criteria is defined by damage parameter which I lowered just to check the failure. During run it shows a warning of high load on certain element but no rupture happens.

Will it not lead to rupture of concrete.

gopal_rathore

Hi @George P Johnson
There are two failure criteria in MAT LAW 24 one with max. plastic strain and another one with damage parameter. I am not able to get any plastic strain output during run and thus not able to use this parameter.

Kindly let me know how to approach failure study of concrete

Thank you

gopal_rathore

Hi @George P JohnsonI have used Istrain 1 in property of solid having tetra elements and then I assigned Epsmax of 0.01 in the MAT LAW 24 card. I was able to see the element failure as attached but not getting the output of plastic strain

 

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Altair Forum User

Hi Gopal,

This seems bit strange as when Istrain is kept failure can be observed. The Help says that the Istrain flag is not used with Material Laws 14, 24 and Material Laws greater than 28. For these materials, the strains for post-processing are always computed. And so this should not make any effect.

I think no plastic strain is developing in the concrete material.

 

Can you try with Sol2SPH option, where the solids are turned into SPH particles, , if the solid is deleted (failure criteria, material law failure).  And you can try with /FAIL/TENSSTRAIN failure criteria.

gopal_rathore

Hi george,

I have seen that in help that IStrain is not applicable for MAT law 24 but it seems to be causing failure in my model. I am sharing the file through secure drop box, if possible kindly have a look over it.

As element failure is happening , there should have been some plastic strain if not there is this being modelled as brittle material?

 

Thank you

Altair Forum User

Hi Gopal,

The failure criteria for /MAT/LAW24 is Eps_max which is total strain criteria.  The keyword for failure based on plastic strain criteria is Eps_p_max. 

And in this model no plastic strain is developing, and concrete is normally considered as a brittle material. 

gopal_rathore

Hi george,

I needed output block on my concrete element which are tetrahedral with steel reinforcement modelled as 1-d beam element. I was not able to get any output block for tetra elements , it is available only for brick elements. 

Is this so?

gopal_rathore

Hi @George P Johnson

Anything on above

 

Thank you

Altair Forum User

Hi Gopal,

I tried in a model and it gave results in HyperGraph for tetra elements.

There is no limitations, you can extract the time history for tetra elements.