Dynamic Vibration Absorbers

A discussion of the dynamic mass absorber (tuned mass damper) and how to tune it for the frequency of a given structural system.

[famine]

This video has taught me more in 27mins than my final year university vibration control professor has in 6 months. Thank you for the clear presentation and detailed explanations!

[yahyasheikhnejad]

very nice explanation and thank you for your time. I enjoyed it a lot.

[Unplannedmoves]

Loved your Knowledge sir and the way you imparted into us.

[hannurissanen]

I'm going to use this theory on my working immediately. Thank you very very much.

[AJ-etvf]

Great, insightful video as usual. I particularly like and appreciate you pointing out what X2k2 = -Fo physically means, specifically that it means that k2 exerts a force on mass m1 equal to Fo which is why the the displacement would be zero. That didn't occur to me why the first time. I just thought that it's a nice, short formula compared to that of X1. Really appreciate these videos and this channel. Very helpful.

[hayden]

Great video - all lectures should do this digitally and clearly like this... One question, Omega = Omage1 = Omega2. If i was to add mass to the table it wont change Omega because this is the frequency of the motor... but it will change the mass term in the equation SQRT(K1/m1), which will change Omega1. I am an engineer and having to dive into a field I haven't looked at for 10 years! Your help would be appreciated!

[muhammadahsan]

Great video, really appreciate the work.

[ammarburhani]

Super good explanation. Good work bro.

[cedericcallens]

If you have a 10 storey building subjected to a wind load, what will be the difference in hanging this secondary mass on 1st, 5th or 10th floor? (Great video)

[fabiozangoli]

Very nice. Gave exactly info I was looking for. Thank you and a question: what tablet did you use for your presentation?

[justincontreras]

Your videos are awesome. Are you a professor/lecturer?

[stitaswain]

great sir ... thank you for the awesome video

[ticheroi]

As always very understandable, informative and interesting)

[정재덕-xk]

I think, It seems that the impedance matrix you mentioned is the dynamic stiffness matrix. Is that right?

[alieltair]

Hello, thank you for this it was very helpful. Is there any way I can get some sort of formal citation to reference it for an essay I am writing?

[JoakimStenudd]

Great video, very much helpfull. But one question, is there a way to go the other way around, to cancel out the movement of mass 2 with mass 1? When looking at the eq. 15 and 16 it looks impossible because the numerator is 1 in eq 16. I understand that the purpose of mass 2 is to absorb vibration from mass 1 but lets just imagine for a second we have a 2-dof system and try to achive this.

[Hudmyq]

Hi, Freeball,

It's me again. Thanks for your video. I'm working on the vibration absorber recentely. Based on equation 1 and 2, I have designed a simulink program to investigate the displacement of m1. However, as your conclusion shown on the end of your video, the displacement m1 isn't zero when the excitation frequency is equal to natural frequency of m1 and natural frequency of m2. Is it matlab problem ? or do we miss something here ?

[johnymacgyver]

Thank you freeball, very understandable for describing equations from the book.
may i ask? if i were to make a model of vibration absorber like this, i could have known the value of m2 i give to the system, but how could i calculate the value of k2 to assure me that the mass2 will definetly neutralize the response of the main system (X1)?
and is there a way for adjusting stiffness for the vibration absorber?
thank you, sorry for bad english

[yogisetiawan]

@Freeball99 let say if we have vertical tower to damp where the base of tower have been fixed with the ground, what is means by M1? Is it entire mass of tower? (Just try ti make analogy to solve something in my system). Thanks

[abraiz]

Where can I find the mathematics behind the damping of a pendulum type tuned mass damper with explanations? Not a spring-mass one