Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

how to couple 2D mindlin plate element and 3d Euler beam element?

Please login with a confirmed email address before reporting spam

Hi, every one!
Now I am trying to couple 2D mindlin plate element and 3d Euler beam element to build a stiffened plate to construct modal analysis. It can works after using extrusion coupling variables, but the result seems wrong. Does anyone can help me? My m document has been attached. Thanks!


3 Replies Last Post 5 nov. 2011, 05:12 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 4 nov. 2011, 16:22 UTC−4
Hi

3.5 is definitively too old for me now, but the difficulty by coupling Euler beam and other structural physics is to get all dependent variables correctly linked, in particular the rotations

--
Good luck
Ivar
Hi 3.5 is definitively too old for me now, but the difficulty by coupling Euler beam and other structural physics is to get all dependent variables correctly linked, in particular the rotations -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 4 nov. 2011, 22:33 UTC−4
Ivar, thanks for your reply. I am using the script of 3.5. Could you help me to check the process of operation since it is not very complex? I just don't know where it's wrong.

As far as I know, dependent variables for Mindlin plate element include "w","thx","thy", and "u","v","w","thx","thy","thz" for 3D Euler beam element in COMSOL. I think the variables "w‘,'thx','thy' have the same meaning, so my idea is to couple these three variables in the beam section of stiffened plate. By the way, the reason of choosing Mindlin plate elment is that it can only describe the bending motion of plate excluding other motions like longitudinal tension. Then, I construct the process as following:

1. use extrusion boundary coupling variables (give the name w1 thx1 thy1) to link all the variables "w","thx'"thy"of section of base plate to the stiffened beam.
2. set the prescribed displacement constrain for the stiffened beam (w1 thx1 thy1).
3. choose all the variables in solver manager and then compute.

That's all the main operations, is there any problem? Thanks for all of attention.
Ivar, thanks for your reply. I am using the script of 3.5. Could you help me to check the process of operation since it is not very complex? I just don't know where it's wrong. As far as I know, dependent variables for Mindlin plate element include "w","thx","thy", and "u","v","w","thx","thy","thz" for 3D Euler beam element in COMSOL. I think the variables "w‘,'thx','thy' have the same meaning, so my idea is to couple these three variables in the beam section of stiffened plate. By the way, the reason of choosing Mindlin plate elment is that it can only describe the bending motion of plate excluding other motions like longitudinal tension. Then, I construct the process as following: 1. use extrusion boundary coupling variables (give the name w1 thx1 thy1) to link all the variables "w","thx'"thy"of section of base plate to the stiffened beam. 2. set the prescribed displacement constrain for the stiffened beam (w1 thx1 thy1). 3. choose all the variables in solver manager and then compute. That's all the main operations, is there any problem? Thanks for all of attention.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 5 nov. 2011, 05:12 UTC−4
Hi

V3 is old and I have already forgotten most (and I do not have any active licence up running) but if I remember right you might use the same u,v,w, but I'm not 100% sure, it needs some simple tests.
But, even if their names are the same, I do not believe that thx,y,z are 100% equivalent in plate and beam physics, in which case you need indeed bidirectional coupling variables to join them, while the others u,v,w might end up coupled by default

By the way in V4 the rotationa angles have different names ;)

--
Good luck
Ivar
Hi V3 is old and I have already forgotten most (and I do not have any active licence up running) but if I remember right you might use the same u,v,w, but I'm not 100% sure, it needs some simple tests. But, even if their names are the same, I do not believe that thx,y,z are 100% equivalent in plate and beam physics, in which case you need indeed bidirectional coupling variables to join them, while the others u,v,w might end up coupled by default By the way in V4 the rotationa angles have different names ;) -- Good luck Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.