Need a book? Engineering books recommendations...

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

RE: Seismic Piping Question

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Here's my take on this: 

Since it is related to seismic forces, I assume that the "deformability"
relates to the ability of the piping to deform
laterally (such as in bending) during an earthquake. Consider connection
types as well as piping materials. 

If a given piping system were a very brittle material with no plastic range,
the ultimate deformation divided by limit deformation, i.e. deformability,
would be about 1/0.80 = 1.25. Thus a low deformability element with a
deformability less than 1.5 would be a very brittle material. 

A ductile steel material with a high ultimate strain relative to yield
strain likely would have an ultimate deformation in excess of 3.5 times the
limit deformation. Thus, I would consider a ductile steel piping system to
be a high deformability system. 

Review the materials used for the piping. For materials not clearly brittle
or ductile, assume limited deformability. 


William C. Sherman, PE 
(Bill Sherman) 
CDM, Denver, CO
Phone: 303-298-1311
Fax: 303-293-8236
email: shermanwc(--nospam--at)cdm.com


> -----Original Message-----
> From: Brian S Bossley [mailto:bsbossley(--nospam--at)venturaengineering.com] 
> Sent: Monday, May 17, 2004 9:30 AM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Seismic Piping Question
> 
> 
> I know it's not an exciting question, but could anyone help 
> me out with this one?
> 
> 
> I have a question in regards to the seismic design of a 
> piping system in IBC 2000/ ASCE 7-98.
> 
> Basically, how do I determine the deformabilty of a piping 
> system to know whether or not it's a high deformability, 
> limited deformability, or low deformability piping system?  
> If I look at ASCE 7, it gives definitions for these terms, 
> but while the limit deformation may be within yield strength 
> parameters, the ultimate deformation is deformation of a pipe 
> in the plastic range.  How do I determine this?  And how is 
> this load applied? In bending? In axial load?  As an inner pressure?
> 
> Any help or direction you could give me would be most appreciated
> 
> Brian S. Bossley, EIT
> Ventura Engineering
> 7610 Olentangy River Rd.
> Columbus, OH 43235
> (614) 847-1110 x121
> 
> 
> 
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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 
> ******* ****** ****** ****** ******* ****** ****** ******** 
> 

******* ****** ******* ******** ******* ******* ******* ***
*   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 
******* ****** ****** ****** ******* ****** ****** ********