XANSYS Message #: 25694

XANSYS Message: 25694 [Go back to message list]
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Subject: Re: different load steps
Author: Bill Bulat
Date: 2001-07-09 12:28:00

Hi Satish, If you wish to calculate mechanical stresses produced by processing, you may also want to review the element birth and death feature (EKILL and EALIVE commands) as well as the MPAMOD command. Careful: ANSYS uses a secant definition for thermal coefficient of expansion, NOT "instantaneous" or tangent. Check the online documentation for details. cheers Bill Bulat OMM -----Original Message----- Sent: Monday, July 09, 2001 6:52 AM To: 'xansys ' I'm not an expert at electronics packaging, but basically you can apply the loads to the solid model entities using say, SFA to apply a heat flux (I am assuming you're interested in thermal analysis), or BFA or BFV for heat generation. You would solve that load step. Then for more loadsteps you just delete the old loads and then apply whatever new loads you would want and solve again. This is a very basic description of the process, and many different ways of applying the loads. You can also apply loads via a table or function for time varying loads, such as in a transient analysis. This is all described in great detail in the Thermal Analysis Guide, along with examples of steady state and transient thermal analyses. I strongly suggest you study that, and start with simple problems that you can verify with hand calculations, so that you can at least understand the methodology and the physics of it before you start looking at your boards. Hope that helps. John Ceko P. Eng. HUSKY Injection Molding Systems Index Development Engineering 560 Queen St. S. Bolton, Ontario, Canada, L7E 5S5 Tel. (905) 951-5000 ext. 3347 Fax (905) 951-5365 Email: jceko@h... -----Original Message----- Sent: 2001, July 09, Monday 9:14 AM To: xansys Say for eg:- a TBGA package and I wish to apply different load steps to the heat sink and card. I am sorry about not including my full details. Satish Guttikonda, Graduate Research Associate, IEEC, SUNY Binghamton, Binghamton, NY 13905. --- In xansys@y..., "Ceko, John (Bolton)" wrote: > What do you mean by different components of the same package? Could you > explain that a little more, please? > Also, it's the etiquette of the list to include your full name and company > or educational afiliation. > John Ceko P. Eng. > HUSKY Injection Molding Systems > Index Development Engineering > 560 Queen St. S. > Bolton, Ontario, Canada, L7E 5S5 > Tel. (905) 951-5000 ext. 3347 > Fax (905) 951-5365 > Email: jceko@h... > -----Original Message----- > From: satishchandrag@y... [mailto:satishchandrag@y...] > Sent: 2001, July 09, Monday 8:40 AM > To: xansys@y... > Subject: [xansys] different load steps > Could someone tell me if I can apply different load steps to > different components of the same package and if yes, how do I go > about it. > Thanks, > Satish

Posts possibly associated with message #25694		Author	Date
`25678`	`different load steps`	`satishchandrag@`	`2001/07/09`
`25679`	`Re: different load steps`	`John Ceko`	`2001/07/09`
`25680`	`Re: different load steps`	`satishchandrag@`	`2001/07/09`
`25683`	`Re: different load steps`	`John Ceko`	`2001/07/09`
`25685`	`Re: different load steps`	`Steve Groothuis`	`2001/07/09`
`25687`	`Re: different load steps`	`satishchandrag@`	`2001/07/09`
`25694`	`Re: different load steps`	`Bill Bulat`	`2001/07/09`
`38532`	`contact analysis---PARAMETERS IN DIFFERENT LOAD STEPS`	`Liang Shaomin`	`2002/06/05`
`38547`	`Re: contact analysis---PARAMETERS IN DIFFERENT LOAD STEPS`	`George Carlson`	`2002/06/06`
`38642`	`How to change the real const in different load steps`	`Liang Shaomin`	`2002/06/09`
`38648`	`Re: How to change the real const in different load steps`	`Roberto Porto`	`2002/06/10`