Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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 specify the "Prescribed Displacement" for the given range?
Posted Dec 17, 2010, 1:36 p.m. EST Structural Mechanics Version 4.1 1 Reply
Please login with a confirmed email address before reporting spam
Dear All,
I have a model with a multiple load (boundary conditions) about the 3D coordinate
Details are as stated below,
About X:
Translation : No
Rotation : +10/-5 deg
About Y:
Translation : No
Rotation : +3/-3 deg
About Z:
Translation : +3mm/-3mm
Rotation : +3/-3 deg
the above problem is based on displacement control.
I tried "Rigid Connector" option is doesn't responds to the rotation (some bug I believe) but does the displacement about the coordinate (just as Prescribed Displacement).
Now I have developed equation of motion for rotation along X, Y & Z and applying by using "Prescribed Displacement"
But, Now I am left with the Translation displacement condition about Z axis.
I am quite confused about how to apply the translation motion within the range of -3 to +3 passing through origin
any suggestion ?
or else how could I develop an equation for it !!! and combining the eq for rotation?
Please find the file attached and its done in 4.1 COMSOL version!!
any help please
Thank you
Kind regards
damo
I have a model with a multiple load (boundary conditions) about the 3D coordinate
Details are as stated below,
About X:
Translation : No
Rotation : +10/-5 deg
About Y:
Translation : No
Rotation : +3/-3 deg
About Z:
Translation : +3mm/-3mm
Rotation : +3/-3 deg
the above problem is based on displacement control.
I tried "Rigid Connector" option is doesn't responds to the rotation (some bug I believe) but does the displacement about the coordinate (just as Prescribed Displacement).
Now I have developed equation of motion for rotation along X, Y & Z and applying by using "Prescribed Displacement"
But, Now I am left with the Translation displacement condition about Z axis.
I am quite confused about how to apply the translation motion within the range of -3 to +3 passing through origin
any suggestion ?
or else how could I develop an equation for it !!! and combining the eq for rotation?
Please find the file attached and its done in 4.1 COMSOL version!!
any help please
Thank you
Kind regards
damo
1 Reply Last Post Dec 21, 2010, 3:24 a.m. EST
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
Hi
first of all Rigid Connector also rigidifies your boundary (makes it rock solid) it might not be what you want. Then you can add subnodes to the rigid connector and adapt both prescribed displacements and rotations.
for the other points I do not really understand the difficulty, if you select displacement = myvariable you can impose a gven displacement at will, couple it to something else (apart that often you get rather non-linear model and the solver might have some difficulties without some help from your part how to segregate or normalise some of the variables
you can add add a spring (hooked up to in infinite rigid body) by applying a prescribed load Fx = - kx[N/m] * u
--
Good luck
Ivar
first of all Rigid Connector also rigidifies your boundary (makes it rock solid) it might not be what you want. Then you can add subnodes to the rigid connector and adapt both prescribed displacements and rotations.
for the other points I do not really understand the difficulty, if you select displacement = myvariable you can impose a gven displacement at will, couple it to something else (apart that often you get rather non-linear model and the solver might have some difficulties without some help from your part how to segregate or normalise some of the variables
you can add add a spring (hooked up to in infinite rigid body) by applying a prescribed load Fx = - kx[N/m] * u
--
Good luck
Ivar