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Author Topic: Duffing oscilator  (Read 26178 times)
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afpedraza
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on: April 22, 2011, 06:35:59 am » posted from:Bogotá,Cundinamarca,Colombia

We are Andres Fernando Pedraza, and Malory Johana Sanchez From Bogotá. Colombia, we want show a simulation of chaos in duffing oscilator. thanks



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« Last Edit: April 22, 2011, 06:52:29 am by afpedraza » Logged
Fu-Kwun Hwang
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Reply #1 on: April 22, 2011, 08:21:43 am » posted from:Taipei,T'ai-pei,Taiwan

You will find "Upload new EJS jar file." check box, at the same line where you find "submit" button when you edit message.

Click the check box, then select the EJS jar file from your computer (the same file you have attached in the previous message).
Then click the submit (Post) button, and you will find simulation displayed as part of forum message.

You can update the jar file,too!( when you edit the message)
Please try it.  Grin
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afpedraza
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Reply #2 on: April 22, 2011, 09:38:25 am » posted from:Bogotá,Cundinamarca,Colombia

Thanks professor Fun. We hope that it can display the simulation, please let us know if it was possible to see

Very very thanks
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Fu-Kwun Hwang
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Reply #3 on: April 22, 2011, 04:23:12 pm » posted from:Taipei,T'ai-pei,Taiwan

You need to upload the jar file according to the process I have described in my previous message to be able to show the simulation as part of forum message.

I will do it for you now. The simulation will be displayed follow this line.

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
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Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
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Fu-Kwun Hwang
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Reply #4 on: April 22, 2011, 04:29:52 pm » posted from:Taipei,T'ai-pei,Taiwan

I know the problem why it was not working for you now.
You have changed the filename for the jar file created by EJS.

The original jar file was ejs_elastico.jar

It will work for you if you upload the original jar file generated from EJS.
I am eager to find more simulation created by you and your group members.  Grin
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lookang
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http://weelookang.blogspot.com


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Reply #5 on: April 22, 2011, 08:04:59 pm » posted from:Singapore,,Singapore

nice one Andres Fernando Pedraza, and Malory Johana Sanchez From Bogotá. Colombia!

just like to say the facebook fan page connected more people using Ejs to come here
http://www.facebook.com/pages/Easy-Java-Simulation-Official/132622246810575


this duffing oscillator is cool
i read on
and found another cool applets to understand the Ejs version one by afpedraza
http://www.math.udel.edu/~hsiao/m302/JavaTools/osduffng.html
http://www.peter-junglas.de/fh/physbeans/applets/duffingoscillator.html
http://www.scholarpedia.org/article/Duffing_oscillator they look like this
Duffing oscillator is an example of a periodically forced oscillator with a nonlinear elasticity, written as
 (1),
where the damping constant obeys , and it is also known as a simple model which yields chaos, as well as van der Pol oscillator.

from http://dynlab.mpe.nus.edu.sg/mpelsb/me4213/Duffing.html
Duffing oscillator, a 2 degree of freedom oscillator with cubic stiffness.
x’’ + ax’ + x3 – x = b cos(t)
The oscillator can exhibit chaotic (i.e. irregular) oscillations


Question:
how come the applet is 2 mass oscillating so what is the difference between the red and blue mass?
i open the evolution page and study
dv/dt = -k1*x/m*s*(b*x*x-1)-R/m*v+A*Math.cos(w*t)
dv1/dt = -k1*x1/m*s*(b*x1*x1-1)-R/m*v1+A*Math.cos(w*t)

is it to show despite the same equation and same initial conditions, the red and blue mass ends up differently to show chaos?
« Last Edit: April 22, 2011, 09:10:10 pm by lookang » Logged
afpedraza
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Reply #6 on: April 23, 2011, 01:16:56 am » posted from:Bogotá,Cundinamarca,Colombia

red and blue masses have different initial conditions but very close to each other, we want to show how two initially nearby trajectories can be separated into the future.

XoRED=1.50m
XoBLUE=1.51m
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lookang
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Reply #7 on: April 23, 2011, 09:00:29 pm » posted from:Singapore,,Singapore

ic...thx!
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ahmedelshfie
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Reply #8 on: May 04, 2011, 06:02:39 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL

Well, is a nice applet i was busy last days ago so didn't have chance to watch it good work Andres Fernando Pedraza, and Malory Johana Sanchez From Bogotá. Colombia
I llike the simulation.
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desertrose3
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Physics <3


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Reply #9 on: January 18, 2012, 06:05:54 am » posted from:Lahore,Punjab,Pakistan

I see the simulation. Thanks again. ALways informational!
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"That their main business was not put into the mind knowledge which was not there before, but to turn the mind's eye towards light so that it might see for itself." ...Plato's advice to educators(429-347BC)
 
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