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 The information provided may be out of date.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.

Can comsol really not model a pendulum?

Please login with a confirmed email address before reporting spam

Seems like a simple question, but I've had no luck so far... Any ideas?

I want to find the pendulum frequency of a model hanging from a fixed support, ie, the object is in a gravitational field. Can comsol even do this?

2 Replies Last Post 2011年11月5日 GMT-4 05:01
Nagi Elabbasi Facebook Reality Labs

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年11月4日 GMT-4 23:39
You can to model the pendulum body with a stiff material, constraint part of it to a rigid connector point. Then fix the translation of that point, keep one rotation free, add gravitational body force and perform a transient analysis. Include geometric nonlinearity if you want to account for the effect of large pendulum angles.

Alternatively, you can implement the pendulum equation of motion directly using the equation based modeling capabilities of COMSOL!

Nagi Elabbasi
Veryst Engineering
You can to model the pendulum body with a stiff material, constraint part of it to a rigid connector point. Then fix the translation of that point, keep one rotation free, add gravitational body force and perform a transient analysis. Include geometric nonlinearity if you want to account for the effect of large pendulum angles. Alternatively, you can implement the pendulum equation of motion directly using the equation based modeling capabilities of COMSOL! Nagi Elabbasi Veryst Engineering

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 2011年11月5日 GMT-4 05:01
Hi

probably the simplest is to use a euler beam (2D and 1 line to draw, then as Nagi said, attach one point but let rotations free, and add a virtual mass at the other end.

If you draw the line with an angle (parametris a rotation in the geoemtry) you can change the initial starting point. And with gravitational forces you have everything you need ;)

--
Good luck
Ivar
Hi probably the simplest is to use a euler beam (2D and 1 line to draw, then as Nagi said, attach one point but let rotations free, and add a virtual mass at the other end. If you draw the line with an angle (parametris a rotation in the geoemtry) you can change the initial starting point. And with gravitational forces you have everything you need ;) -- 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.