Modelling of a Loudspeaker driver

[JesperP85]

Hi Guys

I am very new to Elmer, but have used commercial FEA programs before. I want to attempt to model the magnetic and mechanical system of loudspeaker. I would like to start off just doing a harmonic 2d axisymmetrical model of the magnetic system coupled to a structural domain, can someone point me towards some tutorial/discussions about something like this.

BR Jesper

[kevinarden]

You can go here to see the documentation and basic tutorials. Working through the basic tutorials gives a feel for how the workflow goes. I use Salome for mesh creation and paraview for post processing.
http://www.nic.funet.fi/pub/sci/physics/elmer/doc/
You want to look at Chapter 4 of the models manual

You can go here to get test models for magnet to dynamics
https://github.com/ElmerCSC/elmerfem/tr ... dalforce2d

go up one directory to see many more mgdyn test cases.

[kevinarden]

I extended the tutorial on the Magnetic field resulting from a permanent magnet to add a plate in front of the magnet. I added the solver to calculate the magnetic force and nodal force. But when I add the solver for elastic displacements, those forces did not move the plate. I expect I did not get the interaction to the elastic equations correct.
Mesh and sif files in the git. potential.sif calculates the potential like the tutorial. force.sif calculates the magnetic and nodal forces. displace.sif attempts to displace the plate.
https://github.com/mrkearden/magnet

mag_strength.png

(74.61 KiB) Not downloaded yet

nodal_force.png

(38.56 KiB) Not downloaded yet

[kevinarden]

I was able to resolve the problem of moving the plate with the magnet and was able to pulse the plate by turning the magnet on and off.
Plate displacement over time

pulse.png (12.56 KiB) Viewed 3534 times

Nodal force from magnet

nodal_force.png

(31.14 KiB) Not downloaded yet

sif file

displace.sif

(5.24 KiB) Downloaded 332 times