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

RE: Fatigue and Bowling Pins

[Subject Prev][Subject Next][Thread Prev][Thread Next]
It has been a little while since I have done fatigue work, but I do remember
reading that some materials exhibit better fatigue characteristics if they
"rest" in between large loads as compared to a comparable loading applied in
a non-stop series of cycles.  I don't remember the difference being
particularly large, but it was measurable.  Perhaps it has something to do
with stress relaxation occuring at the microscopic level at crack initiation
points?  Since it is not feasible in most situations to rest the material
(not able to take planes or bridges out of service after each use) I don't
think this is applied very often and probably isn't in too many texts.
Again, this is all something I haven't thought about in 6 years so I don't
have many details, but it could be related.  Try stopping by your location
university library and checking out a few of their more obscure fatigue
texts if you need more.

Paul Crocker, P.E.


-----Original Message-----
From: Balmer James [mailto:James.Balmer(--nospam--at)rsandh.com]
Sent: Wednesday, January 09, 2002 10:50 AM
To: 'seaint(--nospam--at)seaint.org'
Subject: Fatigue and Bowling Pins


I recently heard that bowling pins are routinely taken out of service for a
few weeks to extend their service life.  I confirmed this by calling a few
local alleys.  For a pin left in continuous service, service life is X
weeks.  For a pin that is routinely removed from service, service life is
C*X weeks.  Where C is greater than one and the service life ignores the
"rest" periods.

Is this a old wives tale created by a bowling pin salesman or is there a
reasonable explanation for this?

James

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