Fall 2012 ME 395 - GSI Josh Lacey
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Fall 2012 ME 395 - GSI Josh Lacey

This is a discussion forum for Josh Lacey's lab sections of Fall 2012 ME 395.
 
HomeHome  Latest imagesLatest images  SearchSearch  RegisterRegister  Log inLog in  

 

 Graphing Problem

Go down 
2 posters
AuthorMessage
sinalex




Posts : 9
Join date : 2012-09-12

Graphing Problem Empty
PostSubject: Graphing Problem   Graphing Problem Icon_minitimeMon Sep 24, 2012 2:51 pm

GSIOverlord: How do we graph the damped oscillations from the dynamic test with the curve? We know the max frequency, but we cant figure out how to get the damped oscillation data points to have a curve with it to find the amplitudes of successive peaks.
Back to top Go down
GSI Overlord
Admin



Posts : 126
Join date : 2012-08-30

Graphing Problem Empty
PostSubject: Re: Graphing Problem   Graphing Problem Icon_minitimeMon Sep 24, 2012 8:24 pm

I assume you are talking about getting the peaks that you need for the log-decrement method. There's no one 'correct' answer to this, but you will most likely want to program some kind of algorithm using Excel or Matlab that picks off those peaks for you. Think about what mathematically is happening at each local maximum as a starting point for the algorithm. If you can't figure out a way to do it programmatically, you could of course use visual inspection to find the peaks, although the brute force approach would probably take more time.
Back to top Go down
http://fall2012me395.forumotion.com
GSI Overlord
Admin



Posts : 126
Join date : 2012-08-30

Graphing Problem Empty
PostSubject: Re: Graphing Problem   Graphing Problem Icon_minitimeTue Sep 25, 2012 12:29 am

Actually, it may just be easier for the log-decrement method to do a visual inspection, since you only need two successive, positive peaks. However, if you are trying to fit a curve to all the successive positive peaks, then you'll need a program, I suspect.
Back to top Go down
http://fall2012me395.forumotion.com
Sponsored content





Graphing Problem Empty
PostSubject: Re: Graphing Problem   Graphing Problem Icon_minitime

Back to top Go down
 
Graphing Problem
Back to top 
Page 1 of 1

Permissions in this forum:You cannot reply to topics in this forum
Fall 2012 ME 395 - GSI Josh Lacey :: Lab Questions :: Lab 2-
Jump to: