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.

SDOF (mechanical simple oscillator)

Please login with a confirmed email address before reporting spam

Hi, I've a problem with the mechanical simple oscillator. I do the system with node pinned, spring and mass, then I launch the calculation. I wait the sinousoidal graph, but the result is a sinousoidal graph tending to zero. I don't set a damper. Why ? Where am i wrong ?

P.s. I've attached the graph



1 Reply Last Post 2019年12月18日 GMT-5 07:03
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 2019年12月18日 GMT-5 07:03

Hi,

It can be caused by numerical damping in the time-integration algorithm, even though the damping seems surprisinly strong here. If you are using BDF, try Generalized alpha instead. Solver settings, as wel as things like tolerances and time steps can affect the outcome.

Regards,
Henrik

-------------------
Henrik Sönnerlind
COMSOL
Hi, It can be caused by numerical damping in the time-integration algorithm, even though the damping seems surprisinly strong here. If you are using BDF, try Generalized alpha instead. Solver settings, as wel as things like tolerances and time steps can affect the outcome. Regards, Henrik

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.