XANSYS Forum Index
    Register    

FAQ    Search    Memberlist    Usergroups    SmartFeedSmartFeed    Profile    Log in
[Xansys] [ EMAG ] Force calculation
 
This forum is locked: you cannot post, reply to, or edit topics.   This topic is locked: you cannot edit posts or make replies.    XANSYS Forum Index -> XANSYS
Author Message
mike.yaksh
User


Joined: 05 Feb 2009
Posts: 291

PostPosted: Fri Sep 18, 2009 4:35 am  Reply with quote

Hi Vijay

One way would be to model a small gap (of air) between the two faces.
Unless the faces are "optically" so there is no gap, there is going to
be an air gap. In many designs there may be some type of non-magnetic
spacer, which would be the same as an air gap. If you still need to
treat this as having no gap in the model. You could evaluate the force
using the path form of the Maxwell's stress tensor, after the path is
defined (across the face of the actuator) using FOR2D. This will treat
it as having an air gap. The macro does not check for the material
properties as does FMAGBC. It will use air, which is physically
correct, since due to the surface roughness of the material, there will
be some gap. This will over estimate the force, since with surface
roughness some of the surface area of the pole may not develop a force.
In times pass, some proprietary tests have been conducted by companies
to better define the "gap" in the model when the actuator is closed. In
many cases, when the gap is small, the size of the "small" gap may not
be significant since the reluctance is being controlled by saturation of
other parts of the model. This can be assessed by computing the MMF on
a path around the coil and looking at the MMF plot (PLPA, MMF)(you need
to remove the PDEF,CLEAR from the MMF macro in the APDL directory)

Mike Yaksh
NAC International
Norcross GA

-----Original Message----- Vijay Anand

For simple solenoid having plunger at closed position , I want
to calculate the holding force in the plunger.
Here Plunger is not fully enclosed by air. At the Closed end , plunger
is in closed position with iron path.

Please give me idea how can i calculate the force here.

Post generated using Mail2Forum (http://www.mail2forum.com)
Back to top
View user's profile Send private message
vijay.anand
User


Joined: 21 Oct 2008
Posts: 7

PostPosted: Fri Sep 18, 2009 9:09 pm  Reply with quote

Thanks Mike , I'll try this idea.


Thanks & Regards

Vijay Anand

>>> On 9/18/2009 at 5:05 PM, in message <--email address suppressed-->, "Yaksh, Mike" <--email address suppressed--> wrote:

Hi Vijay

One way would be to model a small gap (of air) between the two faces.
Unless the faces are "optically" so there is no gap, there is going to
be an air gap. In many designs there may be some type of non-magnetic
spacer, which would be the same as an air gap. If you still need to
treat this as having no gap in the model. You could evaluate the force
using the path form of the Maxwell's stress tensor, after the path is
defined (across the face of the actuator) using FOR2D. This will treat
it as having an air gap. The macro does not check for the material
properties as does FMAGBC. It will use air, which is physically
correct, since due to the surface roughness of the material, there will
be some gap. This will over estimate the force, since with surface
roughness some of the surface area of the pole may not develop a force.
In times pass, some proprietary tests have been conducted by companies
to better define the "gap" in the model when the actuator is closed. In
many cases, when the gap is small, the size of the "small" gap may not
be significant since the reluctance is being controlled by saturation of
other parts of the model. This can be assessed by computing the MMF on
a path around the coil and looking at the MMF plot (PLPA, MMF)(you need
to remove the PDEF,CLEAR from the MMF macro in the APDL directory)

Mike Yaksh
NAC International
Norcross GA

-----Original Message----- Vijay Anand

For simple solenoid having plunger at closed position , I want
to calculate the holding force in the plunger.
Here Plunger is not fully enclosed by air. At the Closed end , plunger
is in closed position with iron path.

Please give me idea how can i calculate the force here.



Larsen & Toubro Limited
Electrical & Electronics Division - EBG
http://www.LNTEBG.com

This E-mail may contain confidential or privileged information for the intended recipient(s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.

Post generated using Mail2Forum (http://www.mail2forum.com)
Back to top
View user's profile Send private message
Display posts from previous:   
This forum is locked: you cannot post, reply to, or edit topics.   This topic is locked: you cannot edit posts or make replies.    XANSYS Forum Index -> XANSYS
All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group

sleek template created by Andrew Charron