Which FEA should I use for solenoid calculations? 1

[Jake110]

I don't know anything about FEA programs but I was told to use one instead of trying to calculate everything myself.

I'm trying to find out the force exerted by the solenoid on an object on axis beyond the pole. I was wondering if anyone here knows the best FEA to use for this kind of analysis.

 

[BobM3]

Is it axisymetric? If so, a 2d package would work. Femm is free. I use Quickfield (Tera Analysis; it's similiar to Femm).

 

[dgallup]

When I tried FEMM many years ago it was not very accurate. I believe they have made substantial improvements since then but I've not had the time to check it out.

I've been using Infolytica's Magnet for about 10 years. Their 2D solver is very good. It can do electrical transients with motion.

 

[Jake110]

ok, I've checked out Femm and been through the magnetic tutorial. It seems to me that it can work out the magnetic flux desnity (as well as a few other values) which is handy but its not quite at detailed as i was looking for.

Is there an FEA that can also work out the Force applied to an object at X range?

I'll check out Infolytica's Magnet in the mean time. (MagNet v7 seems to be the latest on from them)

 

[BobM3]

Quickfield will do that. You have to "draw" a box around the area you are interested in. The software will then do the integrations to come up with the magnetic force acting on that enclosed area. It's fairly simple with solenoids.

 

[Clyde38]

Hi Jake,
I use Flux3D, from Magsoft. It certainly has the capability to do what you want. I would consider this solution a very pricey one. If one of the free packages offered will do the job, you should use it. There is a free book by Charles Reginald Underhill, Solenoids, electromagnets and electromagnetic windings at

http://books.google.com/books?id=QN0EAAAAYAAJ

It doesn't cost anything to take a look.

[link

http://www.linkedin.com/in/clydehancock

]

[/url]

 

[israelkk]

FEMM calculates the force at X.

After analysis you move to VieW results. Mark the plunger as a block and select Integrate, Force via Weighted stress Tensor.

 

[israelkk]

All axisymmetric FEA doesn't take into account the side force on the plunger and friction between the plunger and housing. For some solenoids the friction force due to side force can be in the same magnitude of the pull force.

Ledex® Low Profile solenoids are good example. If you will do an analysis of such solenoids you will find that theoretically it should give much higher loads than the catalog says.

Standard FEA will not do transient analysis (including current changes from the voltage step command until final movement of the plunger, or a solenoid operated by a discharged capacitor) which is a must when designing a fast action ON-OFF solenoid valve.

 

[MJR2]

Infolytica is running a 2D solution while I'm typing this. I've used Magnet since the days of '286 and only 2D. Often (but not always) transient solutions can be done in a step wise 2D fashion. We did a lot with 2D when it was all we had.

Mike

 

[Jake110]

I'm seeing if I can find a solution in QuickField, its not got very good instructions but I'll figure it out.

Clyde38 - that book looks very interesting, I'll have to read it some time.

 

[dgallup]

When I worked in France we used Flux2D (it is a French software). I think Infolytica Magnet is much easier to use but they may have improved Flux2D in the decade that has passed.

I agree that axisymmetric analysis ignores side loads but so does a 3D solution if you use perfect CAD geometry, you will have to model eccentricity to get side loads. 3D is generally much too expensive & slow to bother with in solenoid applications.

Infolytica can do a true transient with motion if you have the correct solver options.

 

[FeX32]

For accurate transient analysis. I suggest Comsol Multiphysics.



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