Rotation from Transient Load 2

[MegaStructures]

What would be the best way to calculate how far this object would rotate if a force acted on it for 3-seconds only?

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki

 

[MegaStructures]

Tomfh do you think you could share your excel file?

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki

 

[WARose]

I interpreted the original question to be essentially "Where would the object, in this case a rod, be after holding the force for 3 seconds?". If I understand the answer correctly, it would move a maximum of 24" horizontally and rise about 0.4" vertically but not necessarily at 3 seconds.

I came out with it hitting its peak rise height at 3.83 seconds. (0.83 seconds after the 1500 lbs force is (presumably) ended.)

 

[BAretired]

So it appears that the c.g. of the rod, at precisely 3 seconds, would have deflected less than maximum. That is not what I would have expected. I would have expected it to be less than maximum, not because it is still moving out, but because it is moving back.

Thanks Tomfh and WARose for taking the time to perform these calculations.

BA

 

[WARose]

So it appears that the c.g. of the rod, at precisely 3 seconds, would have deflected less than maximum. That is not what I would have expected. I would have expected it to be less than maximum, not because it is still moving out, but because it is moving back.

I didn't consider once it stopped rising. (And began swinging back. I.e. after 3.83 seconds.) But I would think (by conservation of energy) it wouldn't rise any higher swinging back the other way. (And that especially is true if you consider friction.)

 

[BAretired]

I can see I have a lot to learn about dynamics.

BA