Learning Forum

[asade010]

Hello,

I am trying to use EREINF command to embed my reinforcement in my solid concrete elements. I am currently not modeling any non-linearity.

When viewing results from a simple analysis there are erroneous graphs that make me doubt that the EREINF command is working properly. The reinforcements that are aligned in Z direction are showing bulging with large deformations which is very strange. I have 8 sets of reinforcement defined. 3 of them are in Z direction, all have similar erroneous results. The rest of them look fine.

All my solid elements are quad and I did not change any of them. The loading is displacement control in Y direction upwards.

I would be grateful if someone could take a look at my code and help me. I use version 2019 R1 Academic.

Thanks,

Attached are deformations from two sets of reinforcement (deckl and deckt) in my model.

This is the APDL code I used:

FINI
/PREP7
*SET,MAT_ID,2002                        !STEEL REBAR MATERIAL

DENS_=7850.0
EX_=2.1E+5
NUXY_=0.3

MP,DENS,MAT_ID,DENS_,
MP,EX,MAT_ID,EX_,
MP,NUXY,MAT_ID,NUXY_,

AREA_3=71                ! #3
AREA_4=129                ! #4
AREA_5=200                ! #5


*SET,NEWSEC3,3003

SECTYPE,NEWSEC3,REINF,DISCRETE,n3
SECDATA,MAT_ID,AREA_3,MESH

*SET,NEWSEC4,3004

SECTYPE,NEWSEC4,REINF,DISCRETE,n4
SECDATA,MAT_ID,AREA_4,MESH

*SET,NEWSEC5,3005

SECTYPE,NEWSEC5,REINF,DISCRETE,n3
SECDATA,MAT_ID,AREA_5,MESH

*SET,NEWTYPE,1002
ET,NEWTYPE,200,2

CMSEL,S,NS_DECKL,ELEM                    !!    DECKL
EMODIF,ALL,TYPE,NEWTYPE
EMODIF,ALL,SECNUM,NEWSEC4
CMSEL,A,NS_CONC,ELEM

EREINF

ESEL,S,ENAME,,264                    !!
CM,CM_DECKL,ELEM

CMSEL,S,NS_DECKT,ELEM                    !!    DECKT
EMODIF,ALL,TYPE,NEWTYPE
EMODIF,ALL,SECNUM,NEWSEC4
CMSEL,A,NS_CONC,ELEM
EREINF

ESEL,S,ENAME,,264                    !!
CMSEL,U,CM_DECKL,ELEM
CM,CM_DECKT,ELEM

!!Here is the rest of the definition of reinforcement similar to the two above I removed for this post.

!....

ESEL,S,ENAME,,200
EDEL,ALL

ALLSEL,ALL

FINI
/SOLU

[asade010]

Here are the pics

[asade010]

I really appreciate it if anyone has any idea about what goes wrong here.

I have tried many scenarios, like changing geometry and defining the reinforcement all in one step, but I get similar outcomes.

[Sheldon Imaoka]

Hi asade010,

For the model you have, you mentioned 'all my solid elements are quad', but are you dealing with shell elements (quad) or hexahedral solid elements (hex)?

For the reinforcements, after generating them with EREINF, were you able to visually confirm them by selecting only the REINF264 elements and plotting with /ESHAPE,1?  Did the definition of the elemetns look OK?

I apologize, as it's not clear from the images what is going on, but is it possible that the reinforcements along z-direction are not connected/defined properly?  It seems like the reinforcement elements are rotating (they only have uniaxial stiffness) based on the plots, but is it possible that the underlying elements are also behaving in a strange manner?

Regards,
Sheldon

 

[asade010]

Hi Sheldon,

All my solid elements are hexahedral (185) in this model.

The element definition looks fine as you can see in the above figures these are plots of two sets of defined reinforcement. I just set them based on their type after the ERINF command and then in the solution commands, I plot the sets only not to get too confusing. If I plot as you say (all the 264 elements) simply would be the superposition of the two figures.

My element definition is simply the same for all my sets (see the command lines above). I even tried defining all rebars at the same time but the results would be similar.

I recently opened another discussion and uploaded a small model (a cube with 3 rebars in 3 directions) and got the same strange behavior. You can see that and better understand my issue.

/forum/forums/topic/reinf264-shows-wrong-results/

Looking forward to your reply,

Thanks,

Amir

[Sheldon Imaoka]

Hi Amir,

Thanks for letting me know about your other post.  I provided a reply - please review.

Thanks,
Sheldon