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24-Ruby IV
ValeryOchkov24-Ruby IV
24-Ruby IV
April 19, 2017
Question

Pendulum model

  • April 19, 2017
  • 2 replies
  • 1828 views

I have a 3 pendulum model: 3 masses and 3 links. Links are hard in both direction.

I need some ideas for not hard links but soft string - hard in one direction and soft in other one.

The Mathcad 15 sheet s in attach.

The animation is here:

Video Link : 7750

2 replies

V
vlehner1-Visitor
1-Visitor
April 19, 2017

Hmmmh...

It's a good question and it seems to me that we have to define the length of a string in a little program/routine which allows a variable length.

What about this: use the acceleration when changes from positive values to negative.

If positive we could define the length like l=lo*(1+k1*a).

If negative we could define the length like l=lo*(1-k2*a).

k1,k2 is the "Dehnungskoeffizient" for hard and soft of a rubber-band

Another way could be to define a string as a spring with the hooksche's Law

I'm not familiar with Programming in Mathcad is , so i can't give reasonable solutions in that way.

btw: Great Animation Valery! ...really missing that in Prime...

best regards, Volker

V
24-Ruby IV
ValeryOchkov24-Ruby IVAuthor
24-Ruby IV
April 20, 2017

Thanks, Volker!

I think point masses must sometime free fly...

Fig-10-anim.png

And second.

We can create in Prime n pictures and then create an animation using some others program or Internet.

I have created so one animation and putted it here.

V
24-Ruby IV
ValeryOchkov24-Ruby IVAuthor
24-Ruby IV
April 22, 2017

In attach solution in Prime 3.1 - with units and with... animation!

You can print pictures and make... a clipbook!

One question!

I feel an error in calculation - forces are always negative! Check please!

Frame-1.png

Frame-2.png

Frame-3.png

Frame-4.png

Frame-5.png

Frame-6.png

Frame-7.png

Frame-8.png

Frame-9.png

Frame-10.png

Frame-11.png

Frame-12.png

V
24-Ruby IV
ValeryOchkov24-Ruby IVAuthor
24-Ruby IV
April 22, 2017

No problem to create animation in Mathcad Prime by Internet help!

Video Link : 7776

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