Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Sloshing Damping

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I really would just like a KISS answer.  Is ASCE section 9.14.7.3.10 the
correct section to find seismic shear for granular filled tanks?  Is it a
simple execution of section 9.14.5.2 equations?  Should I just ignore the
0.5% sloshing damping?

Rich


-----Original Message-----
From: Christopher Wright [mailto:chrisw(--nospam--at)skypoint.com] 
Sent: Thursday, November 23, 2006 1:47 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: Sloshing Damping


On Nov 22, 2006, at 10:06 PM, refugio rochin wrote:

> an you tell us about a 3-D element modeling scenario that would work?  
> actually i have never modelled fluids as I suggest.

You can go at it several ways.
--ANSYS has a fluid element that will let you model confined fluids, 
but you'd probably have to do a time-history analysis of the structure 
and the tank all modeled explicitly. It's doable, but a huge pain in 
the ass.
--You could simplify things a lot by adapting Housner's 2DOF model for 
the tank and combine the lumped springs and masses representing the 
liquid with the structural model.
--If your tank didn't happen to be rectangular or cylindrical, you 
could model just the tank and fill it with fluid elements and track 
Housner's development to figure the masses and springs corresponding to 
the particular tank configuration you have, then use them with the 
structural model.
--You could just figure the impulsive and convective pressures from 
Housner's work, make them into equivalent static loads and add that to 
the dynamic response for the tank.

> with computers as they are becoming, it may be very easy to run such a 
> calculation, no?  why not exactly?  it could be an interesting 
> exercise to say the least.
The thing about FEA is that it is very powerful and seems able to do 
lots of things, but FEA doesn't convey understanding. It's a tool, like 
a hammer. People can be very skilled with hammers, but that doesn't 
make them into carpenters and the hammer can't explain when you're 
making a big mistake, even though you've hammered everything within 
earshot.

Christopher Wright P.E. |"They couldn't hit an elephant at
chrisw(--nospam--at)skypoint.com   | this distance" (last words of Gen.
.......................................| John Sedgwick, Spotsylvania 
1864)
http://www.skypoint.com/~chrisw/


******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ******** 



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********