PSN-L Email List Message

Subject: Re: PSN Discussion
From: John & Jan Lahr johnjan@........
Date: Wed, 02 Oct 2002 19:39:00 -0600

Dear Dr. Bauer,

Thanks for getting back to me.  I'll let people know to limit their use to
sub-critical damping.  Is it OK to keep a link on my web site?


At 02:52 PM 10/2/2002 -0400, Wolfgang Bauer wrote:
>I am the author of the applet.  In the html file, I explicitly write that 
>this is only the solution for sub-critical damping.  This is all the 
>applet simulates, and for all those cases the applet provides the correct 
>solution.  I was not interested in supercritical damping, because it would 
>be too involved for the students in my class.
>The case m=k=1 and b>2 is supercritical.  I should, perhaps, have written 
>a warning into the applet output when supercritical cases are 
>reached.  For those, the applet does not work.
>W. Bauer
>On Wednesday, Oct 2, 2002, at 08:51 US/Eastern, Gerd Kortemeyer wrote:
>>Thanks for the bug report. We will look into it.
>>The question regarding usage rights has to be answered by the authors of
>>this applet, namely Profs. Wolfgang Bauer and/or Gary Westfall.
>>The applet is now part of the repository of a larger system,
>>- Gerd.
>>John & Jan Lahr wrote:
>>>  Gerd Kortemeyer
>>>Dear Gerd,
>>>Chris has pointed out that the Java code is not displaying things
>>>for large values of damping.
>>>We were looking at this page:
>>>Try, for example, m = k = 1 and then b = 4 and b = 8.  For b = 8
>>>the return to zero is faster than for b = 4, where as it should be
>>>We found the page through, so I don't know if you
>>>even intend for others to use it.  We're working on seismometer
>>>design with students at the Colorado School of Mines and thus
>>>were looking at damped harmonic motion applets.  See:
>>> for what we're up to.
>>>John Lahr
>>>Golden, CO
>>>At 05:21 PM 10/1/2002 -0400, ChrisAtUpw@....... wrote:
>>>>Hey, that was a nice applet! It shows the response for damping at
>>>>and below critical very nicely. However, there seems to be a
>>>>programming error, for high values of damping, say 4, give a MORE
>>>>rapid return to the zero line, when the TRUE response is to take
>>>>LONGER to reach zero! If you have infinite damping, the mass stays
>>>>where it is - it does NOT 'high tail' it back to the zero line!
>>>>       Regards,
>>>>       Chris
>Wolfgang Bauer, Professor and Chairperson
>Department of Physics and Astronomy
>Michigan State University
>4208 Biomedical Physical Sciences
>East Lansing, MI 48824-2320
>Tel.:           (517) 353 8662
>Fax.:           (517) 353 4500


Public Seismic Network Mailing List (PSN-L)

[ Top ] [ Back ] [ Home Page ]