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mass spring system
Posted 2015年9月17日 GMT-4 10:25 Version 5.1 3 Replies
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HI,
I want to model a structure in 2D to where two beams are connected with spring (one is above and another is under) and other sides of the beam is simply supported. I want measure free velocity and mobility of the point load applied to 1st beam.
I use Multibody dynamics and use rectangle to define beam. Is it ok ??
Then how to connect spring to the beams?? and should I have to use rigid domain??
I want to model a structure in 2D to where two beams are connected with spring (one is above and another is under) and other sides of the beam is simply supported. I want measure free velocity and mobility of the point load applied to 1st beam.
I use Multibody dynamics and use rectangle to define beam. Is it ok ??
Then how to connect spring to the beams?? and should I have to use rigid domain??
3 Replies Last Post 2015年9月18日 GMT-4 05:34
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Posted:
9 years ago
Hi
there are a few ways, but the simplest if your spring is connected to "ground" you can select the boundary where your spring is attached and add a BC of "Spring Foundation" type and give the stiffness in the different directions.
Another way is to use a Boundary Load BC and use an equation for the Force of the type -kx*u, -ky*v ... where kx, ky, ... are the spring constants, and then you can make this spring non linear or linked to another part or whatever ...
--
Good luck
Ivar
there are a few ways, but the simplest if your spring is connected to "ground" you can select the boundary where your spring is attached and add a BC of "Spring Foundation" type and give the stiffness in the different directions.
Another way is to use a Boundary Load BC and use an equation for the Force of the type -kx*u, -ky*v ... where kx, ky, ... are the spring constants, and then you can make this spring non linear or linked to another part or whatever ...
--
Good luck
Ivar
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Posted:
9 years ago
Thanks Ivar,
How to get the results in force and free velocity form??
How to get the results in force and free velocity form??
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Posted:
9 years ago
Hi
Forces you get via the reaction forces in the post processing (applies four BC boundaries), these variables must be integrated over the area, check the doc
Velocities are calculated as the time derivative of the displacement (u,v,w) internally these are named in 5.1 (solid.u_tX,solid.u_tY,solid.u_tZ) (earlier version ut,vt... but to get them "smoother" you might need to add a level in the Discretization" and use third or higher order discretization and not the default quadratic type). but time derivatives are only defined if you do a time solver (and use small time steps and higher resolutions
--
Good luck
Ivar
Forces you get via the reaction forces in the post processing (applies four BC boundaries), these variables must be integrated over the area, check the doc
Velocities are calculated as the time derivative of the displacement (u,v,w) internally these are named in 5.1 (solid.u_tX,solid.u_tY,solid.u_tZ) (earlier version ut,vt... but to get them "smoother" you might need to add a level in the Discretization" and use third or higher order discretization and not the default quadratic type). but time derivatives are only defined if you do a time solver (and use small time steps and higher resolutions
--
Good luck
Ivar