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.

Parametric Analysis of Microresistor beam example in MEMS module

Please login with a confirmed email address before reporting spam

I have the following questions on the Microresistor Beam example in COMSOL MEMS module.

1. How can I vary the input voltage from 0 to Vo ( say 5 V ) and get a plot of deflection and temperature distribution ( for the heat transfer and stress - strain module ) in steps of 0.5 V ?

2. I want to study the effect of beam dimensions ( length, width and thickness) on the cantilever deflection and peak temperature. How can I do a parametric study for this case ?


Thanks,
Bijoyraj

1 Reply Last Post Nov 4, 2010, 3:18 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Nov 4, 2010, 3:18 a.m. EDT
Hi

for the voltage, as you do not change the geometry and that I assume you are doing a stationary solving sequence you click on your Study 1 Step 1 stationary and you open the Continuation/Extent tab (last one)

therein you can add a parameter, but this one must be FIRST defined in the Global definition PArameter (lets call it "Param") , then in the solver you hit the + and add Param, and define a range list such as

"0 0.5 1" , or "range(0.0.1,1)"

and you go to your physics Voltage potential boundary node and write V0*Param as input voltage (you could also use V0 directly as parameter, a question of habit)

If you now want to change the geoemtry, you cannot use this method, as it's not "looping" around the full model, only the physics. For the geoemtry you must define new parameters in the Global Definition Parameter list, then replace the fixed dimensions in your geoemtry by these parameter names. Finally you right click the Study 1 and add explicitely a "parametric Sweep node" (this one qwill loop around the full model and change the geoemtry and update the emsh if required). You fill it in as above and off you go.

note that the solver subnodes might not update correctly if you have an exisitng solver there and you change it, this is valid for 4.0, partly 4.0a, but normally its aken correctly care of in 4.1) so one way is first to delete the old study first.

note that when you DELETE the study, you also delete all subnodes and results node that are linked to it, this is sometimes annoying, so its also possible to ADD new studies, but after a while you might have trouble finding your way in all the cnodes generated, therefore renaming them as you go on is usefull

--
Good luck
Ivar
Hi for the voltage, as you do not change the geometry and that I assume you are doing a stationary solving sequence you click on your Study 1 Step 1 stationary and you open the Continuation/Extent tab (last one) therein you can add a parameter, but this one must be FIRST defined in the Global definition PArameter (lets call it "Param") , then in the solver you hit the + and add Param, and define a range list such as "0 0.5 1" , or "range(0.0.1,1)" and you go to your physics Voltage potential boundary node and write V0*Param as input voltage (you could also use V0 directly as parameter, a question of habit) If you now want to change the geoemtry, you cannot use this method, as it's not "looping" around the full model, only the physics. For the geoemtry you must define new parameters in the Global Definition Parameter list, then replace the fixed dimensions in your geoemtry by these parameter names. Finally you right click the Study 1 and add explicitely a "parametric Sweep node" (this one qwill loop around the full model and change the geoemtry and update the emsh if required). You fill it in as above and off you go. note that the solver subnodes might not update correctly if you have an exisitng solver there and you change it, this is valid for 4.0, partly 4.0a, but normally its aken correctly care of in 4.1) so one way is first to delete the old study first. note that when you DELETE the study, you also delete all subnodes and results node that are linked to it, this is sometimes annoying, so its also possible to ADD new studies, but after a while you might have trouble finding your way in all the cnodes generated, therefore renaming them as you go on is usefull -- Good luck Ivar

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.