Electric motor: stator-rotor interference fit modeling 1

[rmeldo]

Hello,

this is my first message in this forum, so be gentle. I have searched the forum but I could not find an answer to my specific question.

My technical problem is modeling the assembly (by interference fit) of the lamination stack of an electric motor into its aluminium housing.

The laminations are 0.4 mm wide and stacked to form a 100 mm long stator (material: mild steel).

I have some occasional experience in FEA simulations with ANSYS, but the company I recently joined do not have a standalone FEA package. We are considering whether to buy the Pro/Mechanica add-on to ProEngineer (WF3). (ANSYS is too expensive for the occasional use we would make of it)

I haven't seen proMechanica and before I contact the salesman I would like to ASK THE FORUM whether the above simulation is within the capabilities of proMechanica, whrther there are limitations and pitfalls I should be aware of and what level of accuracy I can expect from the results.

I also understand there is a standalone version of ProMechanica. what are the differences?

Thanks in advance

Riccardo

 

[seymours2571]

Riccardo,

Pro/Mechanica can perform the interference analysis that you need. It is just a typical contact analysis, no different than the type you would perform in Ansys. However, you do have far fewer options with respect to the contact elements in Mechanica as you do in Ansys.

The accuracy question has been brought up before many times in different forums. The summary is this: The accuracy of the finite element model is mainly dependent on the quality of the analyst. Now, if you expect your interference analysis to involve plasticity then you will have to use Ansys (or some other FEA solver capable of plasticity). Mechanica is a linear solver only, however it can perform some non-linear analysis by performing a series of linear load steps.

Rarely do you ever have to go into the independent version of Mechanica. However, there are some things that you can do in independent Mechanica that you cannot do in the Pro/Engineer integrated verson. For instance, in WF3 you cannot do element exclusion in the integrated version but you can in the independent (however, I believe this has been resolved in WF4). The independent version is better at diagnosing meshing problems, but there again I believe WF4 has made some serious improvements in this department. There are some other things that you can do in the independent version versus the integrated version, but you may have to talk to the sales person to get a complete list.

Hope this helps,

Steve

 

[rmeldo]

Just seen the reply. Thanks for the exhaustive answer.

I owe you a virtual beer.

Riccardo