MPC184 issue

[struppige]

Hello.
I have a question regarding the possibility to display the MPC184 elements. I have encountered this issue in a larger bridge model and to test it, I have created a simple model: a 5m long cantilever beam (BEAM188) with a 5m long joint on top (MPC184). The top joint was loaded with a 10-unit force in x direction and a bottom joint had all DOF constrained. The joint seems to work correctly and the results are ok. My problem is with the fact that I cannot seem to be able to display the joint. This is no problem here, but in my bridge model it is sometimes hard to understand deformed shapes (the MPC184 elements are the bridge bearings, between superstructure and infrastructure).
Is ANSYS not able to display the MPC184 elements, because they are merely internal constraints? Is there a way to display them?
Thanks.

Best Regards,
Mircea

The macro for the simple model:

/PREP7

N,1,0,0,0
N,2,0,0,5
N,3,0,0,10

!!!!! ELEMENTS !!!!!
ET,1,BEAM188
ET,2,MPC184,16,,,1 ! MPC184 element - General formulation

!!!!! MATERIALS !!!!!
! Material - Steel
MP,EX,1,210000E3
MP,PRXY,1,0.3
! Translation DOF stiffness (Ux,UY,UZ)
TB,JOIN,2,,,STIF
TBDATA,1,1

!!!!! SECTIONS !!!!!
! Section for BEAM188
SECTYPE,1,BEAM,RECT
SECDATA,0.05,0.05
! Section for MPC184 - GENERAL JOINT
LOCAL,11,0
SECTYPE,2,JOIN,GENE
SECJOINT,LSYS,11

!!!!! ELEM GENERATION !!!!!
TYPE,1
MAT,1
SECNUM,1
EN,1,1,2
TYPE,2
MAT,2
SECNUM,2
EN,2,2,3

/SOLU

ANTYPE,STATIC

! Boundary conditions
D,1,ALL,0

! Loads
F,3,FX,10

SOLVE

 

[Drej]

Which version of ANSYS are you using? In 13 MPCs are displayed as lines when you issue EPLOT - this is for MPCs defined as general beams or links. From your code you're defining an MPC Joint and hence this I think is a simple constraint and therefore might not be plotted with EPLOT. You may be able to visualise the MPC using "plot > symbols" and checking the constraint equation check box.


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[struppige]

Thank you for your reply.
Yes, MPCs are plotted as lines, but, as you said, only if they are general links or beams. As I suspected all the other MPC formulations are simple constraints and cannot be printed, not even from plot - symbols (I haven't been able to do it, anyway).
I did find an alternate solution. I added a LINK180 element for each MPC from before. The LINK180 had a very small area (1E-3 m2) and the material had a very small modulus of elasticity (1E-3 kN/m2). This way they have no influence on the analysis results and display as normal line elements, which is exactly what I needed.
Thanks for your response, anyway.